Supercritical Fluids - Free Essay Example

I. ABSTRACT (ENGLISH) The experimental determination of the yield of pyrethrins from the Chrysanthemum cinerariaefolium flower is usually carried out with Chromatographic Techniques. A lot of methods about this have been reported over the years [Z-M. ChertY.H. Wang (1996)]. These include HPLC [13 -22], GC [22-26] and SFC [B. Wenclawiak, A. Otterbach (2000) methods. Because of the need for only analyzing the pyrethrins (not reporting for the individual six pyrethrins but analyzing for total pyrethrins), GC was selected as a method of choice. The yield reported from literature usually ranges from 0.91 1.30% of the dry weight [Kolak et al., 1999], 0.60 0.79% [Bakari (2005)], 0.75 1.04% [Bhat (1995)], 1.80 2.50% [Morris et al. (2005), Bhat and Menary, (1984); Fulton, (1999)], 0.50 2.0% [Kiriamiti et al. (2003)], and 0.90 1.50% [Pandita and Sharma (1990)]. However, Casida and Quistad (1995) in their book: Pyrethrum Flowers: Production, Chemistry, Toxicology and Uses (pp123-193), states that it is possible to obtain pyrethrin yield of 3.0% or even more. We obtained, with hexane extraction in a water bath at controlled temperatures and vigorous stirring (with three magnetic stirrers at a speed of 30rpm); pyrethrin yields varying from 0.85 3.76% of the dry weight. To our knowledge, this is the first time to report of pyrethrins yield above 3% envisaged by Casida and Quistad. Key words: Supercritical Fluid Extraction, Supercritical Carbon Dioxide, Pyrethrins, Solvent extraction, Extraction Yield, Gas Chromatography, Pyrethrin concrete, Crude Hexane Extract. III. ABBREVIATIONS AND SYMBOLS GC Gas Chromatography HPLC High Performance Liquid Chromatography SFC Supercritical Fluid Chromatography SCF Supercritical Fluid SCFs Supercritical Fluids SFE Supercritical Fluid Extraction SC-CO2 Supercritical Carbon Dioxide SC Supercritical CO2 Carbon Dioxide et al et alii (and others) pp page % percentage CHE crude hexane extracts BC Before Christ PY pyrethrin PYI pyrethrin 1 PYII pyrethrin 2 C1 cinerin 1 C2 cinerin 2 J1 Jasmolin 1 J2 Jasmolin 2 P1 pyrethrin 1 P2 Pyrethrin 2 A1 area of pyrethrins 1 A2 area of pyrethrins 2 WHO world health organization Fig Pc critical pressure Tc critical Temperature Cp critical point Cm centimeters ~ Approximately oC degree centigrade MPa mega Pascal FID flame ionization detector n-hexane normal hexane mL milliliters /min per minute Soc. Society Eds editions Sci. Science m meters mm millimeters tR retention time k Retention factor R2 Pearson correlation coefficient LOQ limit of quantification LOL limit of linearity LOD limit of detection BOD beyond limit of detection IS internal standard k response factor f relative response factor m micro meters L micro liters rpm revolutions per minute 1.0. CHAPTER 1: Introduction and Literature Review 1.1.0 Supercritical Fluids (SCF) When a fluid is forced to a pressure and temperature above its critical point (Fig. 1), it becomes a supercritical fluid. Under these conditions, various properties of the fluid are placed between those of a gas and those of a liquid. The supercritical state of a fluid is thus defined as one whose liquid and gas are indistinguishable from each other, or one in which the fluid is compressible (i.e. behaves as a gas) while having a density similar to a liquid and, therefore, similar solvating power. Their low viscosity and relatively high diffusivity gives them better transport properties than liquids, can diffuses easily through solid materials and hence faster and better extraction yields. The most important properties of a SCF are its density, viscosity, diffusivity, heat capacity and thermal conductivity. Higher densities of SCFs contribute to greater solubilization of compounds, while low viscosities enable Easy penetration into solids and facilitate flow with fewer hindrances. Manipulating the temperature and pressure above the critical points affects the properties of SCFs and enhances their ability to penetrate and extract targeted molecules from the source materials [1]. Since density is directly related to solubility, by altering the extraction pressure, the solvent strength of the fluid can be modified to exhibit desirable transport properties that enhance its adaptability as a solvent for liquid extraction processes. The density of a SCF is closer to that of liquids and its viscosity is comparable with gases, hence high diffusivity and faster dissolution of solute particles (the diffusivity of SCFs is ~10-4 cm2 s-1 while that of liquid solvents is ~10-5 cm2 s-1). This has contributed to the increasing use of SCF as solvents for extraction purposes. 1.2.0 Supercritical Fluid Extraction (SFE) Supercritical Fluid Extraction (SFE) is a separation technology that uses supercritical fluid as the solvent. Every fluid is characterized by a critical point, which is defined in terms of the critical temperature and critical pressure. Fluids cannot be liquefied above the critical temperature regardless of the pressure applied, but may reach a density close to the liquid state as mentioned earlier. The consumer and public awareness of the health, environmental and safety issues emanating from organic solvents use in chemical processes and above all, the possibility of contaminating the final products with the solvent are forces to reckon with in recent times. This has driven the chemical industry looking for the best separation technologies to obtain natural compounds from high purity and healthy products that are of excellent quality [2]. The high cost of organic solvents, environmental regulations, and new requirements in the medical fields, for all time purer and highly valuable products have also revitalized the need for the development of new but clean technologies for products processing [3]. 1.3.0 Supercritical Carbon Dioxide (SC-CO2) SFE with Carbon dioxide (CO2), for this and many reasons is most unique and is able to save both time and money while retaining an overall extraction precision and accuracy. CO2, therefore, compressed to pressures above its critical pressure [4]; isothermally shows effective solubility powers in the region of its critical temperature [5-6]. Though a lot of SCFs can be adapted as solvents, CO2 is by far, the most extensively used due to its non-toxic, inert and non-flammable nature. It is also inexpensive and is generally environmentally accepted substance [7]. Biological products are often thermally labile, lipophilic, and non-volatile and as such required to be kept and processed at around room temperatures. CO2 has a critical temperature of 31oC which makes it particularly an attractive medium for this task. Other fluids show critical temperatures in the vicinity of critical state but are often difficult to handle and to obtain in pure state, may be toxic, explosive or ecologically unsafe. For such logical reasons, SFE using CO2 has emerged as an attractive unit operation for processing biomaterials. However, its limitations include the difficulty of extracting polar analytes, owing to the non-polar character of CO2, the different recoveries obtained from spiked and natural samples, and the frequent need for clean-up steps after extraction. Poor thermodynamic description of Supercritical (SC) solvent-solute mixtures, high capital cost for its extraction processes and an almost absence of engineering data to facilitate scale-up and design are also the prime factors that limits the use in industrial and commercial scales. For an excellent engineering design requires reliable data on the transport of a given biomaterial into the SC-CO2; such as the thermodynamic properties, fluid-liquid or fluid-solid equilibrium data of the biomaterial in the region of the temperatures and pressures where processing is technically and economically viable. Also, the measurements for the biomaterial plus SC-CO2 mixture in this condition, any mass transfer limitations for the bulk material into the SC solvent and the selectivity for the desired chemical species with the rest of the solubles in the biomaterial is paramount. Nonetheless, SFE with CO2 has great potential in the field of biomaterial processing as evidenced by the many papers published and the communications presented at the recent symposia on Supercritical fluid Technology [8]. CO2 is a good solvent for extracting lipid-soluble compounds and enables a high level of recovery [9]. CO2 is supercritical above 31.10C and 7.38 MPa, which makes it an ideal solvent for extracting thermally sensitive materials such as pyrethrins. 1.4.0 Set-Up and Principle A Pilot plant equipped with two fractionation cells. (1) CO2 pump; (2) modifier pump; (3) solid samples extraction cell; (4) fractionation cell 1; (5) fractionation cell 2; (6) valve. A fluid (CO2) is brought to a specific pressure-temperature combination, which allows it to attain supercritical solvent properties for the selective extraction of active ingredients from the sample matrix of a biomaterial (in this case Pyrethrum). The sample is exposed to the SC- CO2 under controlled conditions; time, temperature, and pressure that allow dissolution of the active ingredients (Pyrethrins) from the sample in the SCF. The dissolved active ingredients will then be separated from the supercritical solvent by a significant drop in solution pressure [10]. Several guiding principles can be utilized to effect the extraction of these ingredients, particularly the quantitative extraction. This ideal extraction method would afford total recovery and high purity of the isolated desired ingredients (Pyrethrins). Due to the inherent variability in density, chemical composition etc, many substances that can be extracted by SFE, modification of the extraction conditions; specificall y temperatures, pressures, and extraction time, may be necessary to obtain maximum extraction yield. In addition to being used for total active ingredient (Pyrethrins) quantification, the pressure-temperature-time variables in this case would be manipulated to allow selective extraction of minute quantities of polar or non-polar analyses from the Pyrethrum sample matrices. This will help attain the optimum extraction time for the process. 1.5.0 Pyrethrum Pyrethrum flowers come from the Chrysanthemum genus. Due to the size, shape, and colour of the petals; and the daisy-like appearance, they are often called painted daisies or painted ladies. Other names given to it are Buhach, Chrysanthemum Cinerariaefolium, Ofirmotox, Insect Powder, Dalmatian Insect Flowers, and Parexan. According to Visiani (1842-1852), it was first recorded in Dalmatia [11]. Other writers [Bakari P. (2005)] believe that the Pharmacist Antun Drobac (1810-1882) from Croatia was the first to prove its insecticidal activity [12]. Yet there are claims that it was first identified to possess insecticide properties in Asia around 1800 or about 300 B.C.[ Jeanne Roberts]; and that the Crushed and powdered plants were used as insecticides by the Chinese as early as 1000 BC. The Pyrethrum contains about 1-2% pyrethrins by dry weight, but approximately 94% of the total yield is in the seeds of the flower [Casida J.E., Quistad G.B. (1995)] [13]. From literature [14] [Coomber H.E. (1948)], the chemical structures of the active ingredients, pyrethrin I and pyrethrin II was identified in 1924 by a German chemist Herman Staudinger and a Croatian scientist Lavoslav Ruika. Kenya is the worlds main producer today, producing more than 70% of the global supply [Casida (1973)]. [15-17] 1.6.0 Pyrethrins Pyrethrins are the natural active ingredients of the chrysanthemum. Pyrethrin I, cinerin I and jasmolin I are esters of the chrysanthemic acid, and cinerin II, pyrethrin II, and jasmolin II are esters of the pyrethric acid. The three chrysanthemic acid esters are referred to as pyrethrins I (PYI), and the pyrethric acid esters as pyrethrins II (PYII) [Essig K., Zhao Z. J. (2001)]. Pyrethrins I, though insoluble in water, are soluble in some hydrocarbons and organic solvents [WHO (1975)]. According to Todd et al. (2003), they are non-volatile at ambient temperatures, non-toxic to mammals and other worm-blooded animals; and highly unstable in light (photodegradable) [Chen and Casida, (1969)], biodegradable [WHO (1975)], but toxic to aquatic animals. They are mainly used for biological crop protection and as domestic insecticides; and are the major formulations of synthetic pyrethroids. Pyrethrins when used in sufficient amounts are very effective in killing many insects. Although pyrethrins are soluble in a number of organic solvents such as hexane, acetone, benzene, petroleum ether, methanol, chlorinated hydrocarbons, etc; other considerations as practical, economic and environmental concerns limit the use of many of these solvents. This reduces the options to just a few. One of the qualities of Hexane in the extraction of pyrethrins is that it can dissolve the active ingredients effectively without dissolving all the other natural contaminants (pigments, waxes, fatty acids, etc), which are present and must be removed. Removing it from the concrete is also possible at lower temperatures, which limits degradation due to prolonged heating. Its low boiling point is also an added quality. Again, it can be recovered for recycling and reduces the weight of the concrete. Above all, it is inexpensive, accessible and environmentally friendly. It is non-toxic, non-corrosive, non-reactive, and non-flammable. 1.7.0 Pyrethrin Extracts Although pyrethrins are soluble in a number of organic solvents such as hexane, acetone, benzene, petroleum ether, methanol, chlorinated hydrocarbons, etc; other considerations as practical, economic and environmental concerns limit the use of many of these solvents. This reduces the options to just a few. Normal Hexane (n-hexane) is the solvent for the extractions. One of the qualities of Hexane in the extraction of pyrethrins is that it can dissolve the active ingredients effectively without dissolving all the other natural contaminants (pigments, waxes, fatty acids, etc), which are present and must be removed. Removing it from the concrete is also possible at lower temperatures, which limits degradation due to prolonged heating. Its low boiling point is also an added quality. Again, it can be recovered for recycling and reduces the weight of the concrete. Above all, it is inexpensive, accessible and environmentally friendly. It is non-toxic, non-corrosive, non-reactive, and non-flammable. The Hexane is heated above ambient temperature, considering its boiling point (pyrethrum is 170 oC 200 oC) [23] as the upper limit; for efficient extraction but raising the temperature has an effect. It promotes and aids degradation of the active ingredients. The concentration of pyrethrins in the concrete is expected to be 30 10% by weight with contaminants. Organic compounds that have lower molecular weights (ester, ether, etc) are soluble in liquid carbon dioxide. Some constituents of pyrethrum are partially soluble in liquid CO2, while others are not. Fatty acids, alkanes, triterpenols, Water, are those slightly soluble yet inorganic salts, amino acids, sugars, carotenoids, and fruit acids are insoluble [Marc Sims, (1981)]. Pyrethrins are very soluble in liquid CO2 due to the lone ketone and at least one or ester in its molecules. The rest of the molecule is hydrocarbon. Normally, GC analysis of the Pyrethrin components is difficult because Pyrethrin I and II undergo thermal isomerization to form isopyrethrin I and II at temperatures above 200oC [24-27]. These temperatures can neither be avoided in split or splitless injection systems nor in the elution from capillary columns. This brings about a transition of the isopyrethrins continuously and lead to improper integration of Pyrethrin I and II the peaks. The use of very short thin film columns combined with an on-column injection system17 will reduce this thermal conversion. Yet even with such columns the capacity and the separation performance will be insufficient. It also means that the natural Pyrethrins will appear together but the overall detection of the total amount of the pyrethrins is therefore feasible. 1.8.0 Properties Pyrethrum is very important due to these key properties: 1.8.1 Action: It attacks rapidly, the nervous system of the insects providing knockdown and killing effects eventually. 1.8.2 Immunity: In fact, there are beliefs that insects developing resistance to Pyrethrum is not practicable due to the complex nature of its structure 1.8.3. Toxicity: For a long time, it has proven to be safe for humans and other warm blooded animals but some claim it is toxic for cats [PetEducation.com], but toxic to aquatic animals even at as 2 parts per trillion [Bhanoo, Sindya (2010)] Green Inc. Energy, Environment, and the Bottom Line. New York Times, https://greeninc.blogs.nytimes.com 1.8.4 Activity: It has a vast spectrum of activity and can be used against any insect species. This is because of its closely related group of compounds (PYI and PYII). 1.8.5 Repellency and inhibition/jamming: Pyrethrum is also used to repel insects in food and grain during storage and personal protection. Beside this, it is also used to inhibit insects biting efficiency [ ] or jam their biting ability 1.8.6 Flushing: It is considered to have the greatest flushing action than any insecticide. It disturbs and flashes out the insects in their hiding outs. 1.8.7 Environment: Pyrethrum is photodegradable and as such is environmentally friendly (half-life of 12 days in soil) [www.ehow.com]. It also decomposes in air and relatively high temperatures and therefore presents no hazards due to persistence [NPTN Fact Sheet]. National pesticide telecommunications network 1.9.0 Pyrethroids Pyrethroids are man-made (synthetic) but chemically stabilized form of natural pyrethrins. Their structures are adapted and resemble that of pyrethrins and as such have similar activities. They are altered to improve their stability and potency.There are two kinds. Type I include tetramethrin, Allethrin, bioresmethrin, resmethrin and permethrin. Some type II pyrethroids are cyfluthrin, cypermethrin, deltamethrin, fenvalerate, cyphenothrin, and fluvalinate. They are persistent compounds (cypermethrin, permethrin and deltamethrin) and are resistant to degradation by air and light and therefore, are appropriate for use in wide applications, but they have higher significant mammalian toxicities (Morgan, 1989). 1.10.0 Synergist Despite the potency and safety of pyrethrum, it has few limitations. Some insects are able to recover from the knockdown effect. Again, because it breaks down in air and sunlight, it looses its effectiveness quickly in outdoor use. These are combated by treating pyrethrum extract with a liquid called Synergist. This has the ability to protect the pyrethrum from breaking down in the insects system. Small quantities of pyrethrum are mixed with these chemicals to effectively and efficiently control insect populations. The most popular of there are MGK-264 and Piperonyl butoxide. 1.8.0 Experiments 1.8.1. Objective The purpose of this experiment is to determine, compare the efficiency and provide a method by which pyrethrins are obtained in an appreciably pure and at the same time stable form (yet economical) from pyrethrum flowers by extracting 1) with an organic solvent (n-hexane) in a Soxhlet extraction and finally obtaining the pyrethrins from the concrete using sc.CO2 (proposed method); and 2) Directly with SC.CO2 and finally dissolving the concrete in organic solvents (methanol, petroleum ether and n-hexane) to obtain the pyrethrins (Factory method). 1.8.2. Chemicals Grounded chrysanthemum cinerariaefolium, Hexane, CO2 SFE grade 1.8.3. Instruments Soxhlet apparatus, burner, and flask, filter paper 1.8.9. SFE apparatus A self built apparatus with the following parts will be used: the pump, cylinder, oven, flow valves, pressure gauges, and thermometers. 1.9.0. Normal (Organic) Solvent Extractions 1.9.1. Water bath Extraction of the pyrethrins from 100g of the grounded pyrethrum flowers with hexane would be conducted in a water bath (YUHUA, DF-101S) in batches at temperatures of 35oC, 40 oC, 45 oC, 50 oC, 60 oC and 70 oC in 3hrs, 4hrs, 5hrs, 6hrs and 7hrs; in a 1000mL round bottomed flask. Agitation would be achieved by stirring vigorously with three big size magnetic stirrers at a speed of 20rpm. The hexane would then be removed with a rotary evapourator (YUHUA, RE-2000B) at a temperature of 25 oC and at a speed of 180rpm; to obtain the pyrethrin concrete (20mL) also called Crude Hexane Extract (CHE). 1.9.2. Chromatographic Conditions A Gas Chromatogram with flame ionization detection (FID); Agilent., HP-5 capillary Column, 30mm 0.25mm id., 0.25um lm thickness would be used. Each run required about 50mins. The instrument would be calibrated with multiple-point standard additions calibration method using the six individual standard samples to be prepared. The peak area of each component in the sample solutions would be fitted within the linear range of the standard. The split/split less injector, in the ratio 20:1, would be kept at 250 C. Nitrogen would be the carrier gas at a ow rate of 1.6L/min with an injection volume of 0.1L. The temperature program would start at 180 oC, kept for 11 minutes, heated at 10C/ min to 200 C, kept for 8 minutes; heated to 210 C at 10 C/min, kept for 18 minutes, then heated to 245C at 30C/min, staying at this temperature for 4 minutes. 1.9.3. SFE Conditions The carrier gas will be Hexane with a constant flow rate of 2mL/min, pressure would be between 13-25Mpa. The temperature program would be from 35-45oC. Contact time would be within 3hrs to 6hrs. References 1) Dunford, N.T., Teel, J.A., King, J.W., 2003, A continuous counter current supercritical fluid deacidification process for phytosterol ester fortification in rice bran oil. Food Research International 36, 175-181. 2) Ravents, M., Duarte, S., Alarcn, R., 2002, Application and possibilities of supercritical CO2 extraction in food processing industry: an overview. Food Science Technology International 8 (5), 269-284. 3) Mohamed, R.S., Mansoori, G.A., 2002. The use of supercritical fluid extraction technology in food processing, featured article food technology magazine, June, The World Markets Research Centre, London, UK. 4) The pressure of a fluid in its critical state; i.e. when it is at its critical temperature and critical volume, source: Answers.com 5) The temperature above which a gas cannot be liquefied, regardless of the pressure applied, source: Answers.com 6) The solubility of naphthalene in supercritical ethylene., J. Am. Chem. Soc 7) Extraction with supercritical Gases, Verlag Chemie, Deerfield Beach, FL 8) Present state of extraction of natural materials with supercritical fluids and development trends in supercritical fluid science and technology, eds, K. P. Johnston and J. M. Penninger, ACS symposium series No. 406, pp. 478-498; Performance of a packed column for continuous SC-CO2 processing of anhydrous milk fat. Biotech, Progress, 9) Awasthi, A., Trivedi, R.K., 1997: A review on supercritical carbon dioxide extraction of natural products, Chemical Engineering World Feature/Article; Fattori, M., Bulley, N.R., Meisen, A., 1988. Carbon dioxide extraction of canola seed: oil solubility and effect of seed treatment. Journal of the American Oil Chemists Society 65, 968-974. 10) Food analysis second edition: crude fat analysis. Purdue University, West Lafayette, Indiana, pp. 203-214 11) Visiani R. (1842-1852). Flora Dalmatica 12) Bakari P. (2005), Buha prirodni insekticid. Gospodarski list 17: 41-45 13) Casida J.E., Quistad G.B. (1995). Pyrethrum flowers: Production, Chemistry, Toxicology, and Uses. Oxford University Press, New York. 14) Coomber H.E. (1948). The chemical evaluation of Pyrethrum flowers, Pyrethrum Post 1 (1): 16-19 15) Chandler S.E. (1948), The Origin and Early History of the Production of Pyrethrum in Kenya. Pyrethrum Post 1 (1): 10-13 16) Mocatta G. (2003). Pyrethrum- from ancient discovery to advanced agriculture; Agriculturalist, Botanical Resources Australia. 17) Jones, G. D. G. Pyrethrum production, In Pyrethrum; The Natural Insecticide. J. E. Cadisa (eds.). Academic Press. New York, NY. 1973. pp 17-21. 18) Essig K., Zhao Z. J. (2001b). Preparation and characterization of a Pyrethrum extract standard. LC/GC 19(7): 722-730 19) Head S.W. (1966). A study of the insecticidal constituents in Chrysanthemum cinerariaefolium. (1) Their development in the flower head. (2) Their distribution in the plant. Pyrethrum Post 8(4): 32-37 20) WHO (World Health Organization). 1975. Data Sheet on Pesticides No. 11; Pyrethrins. www.inchem.org/documents/pds/pds/pest11_e.htm 20) Todd, G. D., Wohlers, D., and Citra, M. Toxicology Profile for Pyrethrins and pyrethroids. Department of Health and Human Services. Agency for Toxic Substances and Disease Registry. Atlanta, GA. 2003. 21) Chen, Y-L., and Casida, J. E. 1969. Photodecomposition of pyrethrin I, allethrin, phthalthrin, and dimethrin. J. Agr. Food Chem. 17: 208-215. 22) W.H.T. Pan, C.K. Liu, L. Y. Chou and M.H. Lee, J. Chin. Med., 5 (1994) 71 23)M. MATSUMOTO, Jpn Patent 119,682, 1974 24) L.W.Levy, Br. Patent 870, 456, 1961 25) G. Foget , J. Toxicol.Environ. Health, 32 (1991) 11 26) V.M.Valentine, Veterinary Clinics of North America-Small Animal Practice, 20 (1990) 375 27) D.A. Otieno, I.J. Jondiko, P.G. McDowell, and F.J. Kezdy, J. Chromatogr. Sci. 20, 566 (1982). 28) Technical Data sheet, Wefco marketing international cc; www. Wefco.co.za 29) Zong-Mao Chen, Yun-Hao Wang, chroma. Methods for the determination of pyrethrin and pyrethroids pesticides in crops, foods and environmental samples; journal of chrom. A. 754 (1996) 367-395 30) Ernesto Reverchon, Iolanda De Marco, Supercritical fluid and fractionation of natural matter; J. of suppercrit. Fluids, 38 (2006) 146-166 31) Carlo Bicchi, Claudio Brunelli, Mario Galli, Abino Sironi, Conventional inner diameter capillary columns: an approach to speeding up GC; J. of chrom. A, 931 (2001) 129-140 32) Thomas J. Class and Joachim Kintrup, pyrethroids as household insecticides: analysis, indoor exposure and persistence; Fresenius J. Anal Chem (1991) 340: 446-453 33) B.W. Wenclawiak, M. Krappe, A. Otterbach, In situ transesterification of the nat. pyreth; J. of chrom. A, 785 (1997) 263-267 34) Wynn H.T. Pan, Cheng-Chin Chang, Tien-Tsu Su, Fong Lee, Ming-Ren Steve Fuh: prep. supercrit. Fluid extract. Of pyreth I and II from Pyrethrum flower; Talanta 42 (1995) 1745-1749 35) Amrith S. Gunasekara, environ. Fate of pyrethrins; depart. Of pesticide regulation 1001 I street, Sacremento, CA 95812: novenmber 2004, revised 2005 36) Martina Gardisa, Klaudija Carovic-Stanko, Ivan Kolak, Zlatko Satovic; Morphological and biological diversity of Dalmatian pyre. Review article. Croatia 37) Ken Essig and Zhouming J. Zhao; Aventis environ. Sci, 95 chestnut ridge road, Montvale, new jersey 07645 38) .[ Jeanne Roberts, www.celsias.com: Insecticide Treated Mosquito Nets and Malaria Prevention: Weighing the Benefits, Naming the Benefactors] 2.0. CHAPTER 2: Report on GC analysis and Organic (Normal) Extractions 2.1.0 Objective The objective of this section of the experiment was to establish standard curves, by gas chromatographic techniques; for pyrethrins 1 (PYI) and pyrethrins 2 (PYII); the two groups of the six essential ingredients (Cinerin 1, Jasmolin 1, Pyrethrin 1; and Cinerin 2, Jasmolin 2, Pyrethrin 2) of the chrysanthemum (with the standard sample provided by the company), and to determine the percentage yields (and global yield) after Hexane (normal) extractions. 2.2.0 Background In analytical chemistry, the accuracy of quantitative measurements of the constituents of samples, using standard samples of known composition usually requires calibration. It is usually, but not automatically, done with samples and standards dissolved in appropriate solvents. This is due to the ease of preparing and diluting accurately, mixture of standard samples. Several standard solutions are prepared and analysed or measured, a line or curve is drawn (fit) to the data points and the obtained equation is used to translate values from the unknowns into corresponding concentrations. It has the advantage that random errors in the preparation and readings of standard solutions are averaged over many standards. Again, non-linearity can be seen and eliminated by fitting into the linear sensitivity range by dilution. Yet still, this can be compensated for by using non-linear curve fitting methods. It is usually, but not limited to a first-order of measured fit signal (area) on the y-axis against concentration on the x-axis. The model equation is: y (signal) = m (slope) * x (concentration) + c (intercept) (1) It is the most common and straightforward method, but its main drawback is that it cannot compensate for non-linearity. A minimum of two data points are needed to construct the curve. The concentration, x of the unknown sample is given by x = (y-c)/m.. (2) Where y is the measuredsignal, m is the slope and c is the intercept from the curve (straight line fit). The value of c is zero if the curve is forced through the origin: then x = y/m.. (3) 2.3.0 Gas Chromatography Gas Chromatography (GC) is a means by which separations, quantifications and identifications of analytes of a given solution or mixture is done. The essentials required for this method are an injection port where samples are placed. There is also a column on where separations of the components are done; a carrier gas whose flow is regulated to carry the samples all along the instrument, and a detector for the identification of analytes as well as a data processor. By this tool, a sample is brought to the vapour form and a carrier gas sends the sample into a column. The carrier gas should be inert; chemically. The choice is often governed by the type of detector which is used. With a gas-liquid chromatography, the column is normally packed with a solid stationary phase. Once the sample moves along the column, the analytes that interact strongly with the phase spend more time in the stationary and the moving gas phases, hence will require more time to travel along the column. There are generally two types of columns: packed and capillary (sometimes called open tubular). Packed columns are 1.5 10m in length and have about 2 4mm internal diameter. Capillary columns are coated with liquid stationary phases or lined with thin layer which adsorb the stationary phase. They are more efficient than packed columns. After exiting the column the analytes once separated are detected by a detector and their response recorded for analysis. The time from injection of a sample to the time an analyte is detected is defined as Retention time tR. The boiling point of the sample is vital in determining retention time. Those with higher volatility (lower boiling points) tend to have shorter retention times as they spend more time in moving from the gas phase. Each analyte (component) will have a different retention time. Retention factor, k, (or capacity factor) is a term used to describe the travel rate of an analyte on a column. If the retention factor is less than one, elution will be quick such that to determine accurately the retention time is difficult; otherwise elution takes a very long time. The retention factor for an analyte is usually between one and five. For optimum efficiency, the volume must not be very large, and must be put in the column as a vapour plug. The most common injection method is the use of a micro syringe to inject the sample. For effective separations, peaks must symmetrical, sharp and hence no band broadening and trailing must be present. The greatest constraint of gas phase chromatography is the vaporization of the solid and liquid samples on the column in the gaseous state. This limits its use usually to the study of thermo stable and sufficiently volatile compounds (1) www.chromatographyonline.com 2.4.0 Determination of the Standard/Calibration Curve A calibration curve provides the relationship between a signal produced by an instrument and the concentration of the analytes being measured. Different analytes produces different and unique signals. The measurements (signals) of an analyte of unknown sample are commuted, from the standard curve into concentrations. Quantitative analysis with GC is based on comparative methods. The Concept is that the sample with the analyte and a standard Sample that has the same concentration of this analyte will produce similar results, using an instrument with the same conditions. Several standards of known are prepared and their concentrations calculated. Then a standard curve is established from the values of the analytical result (in this case; area) as a function of analyte concentration. This standard curve is then used to find the concentration of an unknown sample. Usually, the abscissa (x-axis) corresponds to the concentration and ordinate (y-axis) of the signal result (area). 2.4.1. Regression analysis The import of this analysis is to provide an equation that relates the instrument results to the concentrations used, such that with a given result the corresponding unknown concentration can be determined. The model of the function is y = f (x), defining y. The errors in calculating the concentrations would be acceptable (less) if the signal of the unknown are in the range (middle) of the signals of the standards. 2.4.2. Simple linear regression Once the results of the detectors are linear as a function of the measured variable, then the goal now is to obtain the parameters of a straight line of best fits. The least squares regression line, which reduces the sum of the square or the error of the data points; is represented by the linear equation, y = mx + c.. (4) x is the independent variable, and y is the dependent variable. The term c is the y-intercept or regression constant (c is the value when x = 0), and the term, m; is the slope (sensitivity) or regression coefficient. The Pearson correlation coefficient R2 gives a measure of the reliability of the linear relationship between the x and y values. If R2 = 1, the linear relationship between x and y exists and is exact. Values of R2 close to 1 indicate excellent linear reliability. If the correlation coefficient is far away from 1, the relationship is less reliable. A straight line suggests that the errors in y follow the law of normal distribution and usually, the experimental error is considered to affect the y value only but not the x value (concentration recorded). If the response of any unknown falls outside the range of the standard, then additional work is required. Likewise if it falls below the Limit of Detection, then the sample needs to be concentrated and must be diluted if it lies above the Limit of Linearity. 2.4.3 Calibration Methods There are about three methods for the determination of the standard/calibration curve. These are explained below. 2.4.3.1 External standard method This method involves the comparison of two chromatograms obtained successively but with the same control conditions. The first chromatogram is acquired from a standard solution (reference solution) of known concentration in a solvent, for which a known volume is injected and the corresponding area in the chromatogram is measured. The second chromatogram results from the injection of the same volume of the sample in a solution containing an unknown concentration of the compound to be measured. Since the same volumes of both samples are injected, the ratio of the areas is proportional to the ratio of the concentrations which depend upon the masses injected. For precision, several solutions of varying concentrations are used in order to create a calibration curve. 2.4.3.2 Internal standard method With internal standardization, a second compound, often related to the analyte but never found in the sample, is added at a known concentration to every sample and calibrator. It is the ratio of the analyte to internal standard that is the critical measurement in an internally standardized method. The calibration curve data are generated by injecting calibration samples of different concentrations, that all contain the same concentration of internal standard. The ratio of the analyte area to the internal standard area is calculated and plotted as the y-value against the concentration of the calibrator in x-axis. This compensates for any imprecision resulting from the injected volumes, which is the main drawback of the External standard method. This method relies on the relative response factor of each compound to be measured against the standard. It requires two chromatograms, one to calculate the relative response factors of the compounds of interest, and the other for analysis. The idea of relative response factors arises because the detector does not respond to each analyte in a mixture the same way. The areas of peaks could directly be used, if this was so; to obtain the total composition. This is done by dividing the peak area of each by the total area of the peaks. Hence, every peak area should be multiplied by an appropriate factor known as the response factor, (k) to compensate that. The compensated areas are then what are used to calculate the total mixture composition. Each response factor is then ratioed to that of a chosen component and this is termed relative response factor (f). The relative response factors then enable the determination of the total composition of any unknown mixture of similar components. The regression equation is rearranged as in equation (3), which allows calculation of the unknown concentration. 2.4.3.3. Method of Standard Additions Usually, in both the external and internal standard methods, matrix-based standards are prepared. This implies that the standard to be used for the calibration must not have any traces of the analyte. By this, reduces the likely signal stifling or interference of the matrix. To be exact, a blank matrix sample is analysed to ensure that no interfering peaks exist. Unfortunately sometimes, it is not possible to have an analyte without interfering peaks (free matrix). In such cases, this method is employed. A series of standards are obtained in several different concentrations. The standards are so added to portions of the sample. Several concentrations of the reference sample may be prepared (if available), without an internal standard. Thereafter, the samples are assayed and the corresponding results appropriately plotted. 2.5.0 How to determine an unknown concentration Determination of the unknown concentration of any sample can be done in two ways: 2.5.1. Graphically: Once the signal of the unknown is obtained, a horizontal line is drawn from the signal on the y axis (0.068) to meet the calibration curve and then a vertical line drawn straight down to the concentration on the x-axis (shown with blue arrows). The value at this point (estimated as 0.32M) is the concentration of the unknown sample as shown below. 2.5.2. Mathematically: The equation of the calibration curve is fitted to the data, and solved for concentration as a function of the signal (y). Then, the signal for each unknown is substituted into this equation and the corresponding unknown concentration calculated for. This gives more accurate concentration values compared with the graphical method. The fit equation is as in equation (1) and it is expressed mathematically as in equation (4) above. Solving equation (4) for Concentration (x) yields either equation (2) or (3) depending on whether the fit is forced through zero or intercept at c. i.e. x = (y c)/m (2) Or x = y/m (3) x is the unknown concentration to be calculated. 2.6.0 GC Analysis My first problem was to determine a set of experimental analysis conditions that give a better separation of the six analytes in a pure solution prepared from the standard sample provided by the company, in a reasonable time frame. Several conditions were tested until this particular one below chosen. Identification of the individual peaks was based on the similarities between the peaks produced and those from literature (B.W. Wenclawiak et al, 1997) with different conditions though. Analyses with these conditions were repeated three times for accuracy and reproducibility. Six standard solutions prepared were injected and chromatograms obtained. Replicate injections of each solution were made for precision and accuracy. The peaks from these chromatograms were compared with those found in literature for the identification of the individual analytes and their corresponding retention times noted. After this, the peak areas for PYI and PYII of all the six solutions were calculated by the software and recorded. A plot of these peak areas and the concentrations calculated earlier gave the standard curve for the analysis. 2.7.0 Experimental Procedure 2.7.1 Chemicals and Reagents Hexane: 110-54-3C6H14 97.0%86.18M Ethanol64-17-5 C2H5OH99.7% (46.07M) Ethyl dodecanoate: Filter papers (7cm and 15cm): Finel: filters (0.45m): Syringes (1mL): All the solvents were analytical-reagent grade. Hexane and Ethanol were purchased from Sinopharm Chemical Reagent Co., Ltd and used without any pre-treatment. 2.7.2 Equipment and Apparatus 2.8.0 Samples The grounded chrysanthemum (light green with a characteristic smell) was provided by the company in as well as two samples of the pyrethrum concrete (yellowish in colour). The first sample contained 50% of pyrethrins (i .e. 29.5% of pyrethrins 1 referred to as PYI and 20.5% of pyrethrins 2, called PYII); and the second one had 85.15%, comprising of 46.33% PYI and 38.82% PYII. 2.9.0 Conditions The conditions finally chosen as the best, after a series of conditions tried was: The split/split less injector, in the split ratio 20:1, was kept at 250 C. Nitrogen was used as carrier gas at a ow rate of 1.6L/min. The injection volume was of 0.1 L. The temperature program was started at 180 C kept for 11 minutes, heated at 10C/ min to 200 C, kept for 8 minutes; heated to 210 C at 10 C/min, kept for 18 minutes, then heated to 245C at 30C/min, staying at this temperature for 4minutes. The chromatographic analysis was performed in a gas chromatograph with an FID detector, Agilent GC, HP-5 Column, 30mm 0.25mm id., 0.25 m lm thicknesses. This column was chosen because it gives the best resolution, identication and quantication for products containing OH and C=O. (Rosana, Vanessa, 2003; Analytica Chimica Acta 505 (2004) 223-226). 2.10.0 Standard Curve Once the conditions were established, 2g of the PY concrete was transferred into a 100mL volumetric flask and Ethanol was filled to the mark and shook to mix. Knowing the mass, the concentration of the PY solution (20mg/mL) was then calculated using the relation: Concentration (mg/mL) = mass (mg)/Volume (mL) . (5) The concentration of PYI (9.266mg/mL) and PYII (7.764mg/mL) was calculated keeping in mind the % of each group in the sample provided (i.e. 46.33% and 38.82% respectively). Six standard aliquots; 1mL, 2mL, 4mL, 8mL, 16mL and 32mL of this PY solution was then transferred into a 50mL flask each and diluted with Ethanol again to the mark and mixed. The concentration of each standard portion and the PYI and PYII concentrations were then calculated appropriately. Pure PY sol PY conc.(mg/ml) PYI conc.(mg/ml) PYII conc.(mg/ml) pure sol 20 9.266 7.764 1ml 0.4 0.1853 0.1553 2ml 0.8 0.3706 0.3106 4ml 1.6 0.7413 0.6211 8ml 3.2 1.4826 1.2411 16ml 6.4 2.9651 2.4845 32ml 12.8 5.9302 4.969 Table 1: Concentrations of each standard portion calculated With a micro syringe, 0.1L of each of these solutions were injected into the GC for analysis. The elution times and the corresponding peak areas were noted and recorded. See the table below. Comp. 1ml 2ml 4ml 8ml 16ml 32ml Elution (min) Peak area Elution (min) Peak area Elution (min) Peak area Elution (min) Peak area Elution (min) Peak area Elution (min) Peak area Cinerin1 19.86 20.01 19.87 42.79 19.87 81.28 19.87 174.29 19.88 260.04 19.91 618.90 Jasmolin1 23.11 11.94 23.11 12.86 23.11 24.18 23.11 58.79 23.12 87.79 23.13 209.17 Pyrethrin1 24.27 56.51 24.29 121.83 24.29 227.91 24.31 487.30 24.34 722.69 24.43 1711.29 Cinerin2 38.44 24.09 38.46 37.92 38.47 75.19 38.48 161.23 38.51 238.44 38.57 581.32 Jasmolin2 42.06 19.06 42.07 29.42 42.06 48.35 42.07 114.08 42.07 161.40 42.09 390.64 Pyrethrin2 42.91 4.22 42.91 3.60 42.91 8.09 42.91 18.14 42.92 26.26 42.96 57.89 Table 2: Elution times and peak areas of analytes in standard sample The concentrations and the peak areas are then tabulated to construct the overall standard curves for PYI and PYII respectively. Soln. PY(mg/ml) PYI(mg/ml) A1 PYII (mg/ml) A2 pure sol 20 9.266 4436.5566 7.764 1790.7451 1ml 0.4 0.1853 88.4592 0.1553 47.3710 2ml 0.8 0.3706 177.4739 0.3106 70.9374 4ml 1.6 0.7413 333.3663 0.6211 131.6275 8ml 3.2 1.4826 720.3725 1.2411 293.4468 16ml 6.4 2.9651 1070.5243 2.4845 426.1003 32ml 12.8 5.9302 2539.3593 4.969 1029.8515 Table 3: concentration and corresponding peak areas The Pearson correlation coefficient R2 in each of the curves is about 0.99. From literaturechromatography online, this indicates the measure of the reliability of the linear relationship between the x (concentrations) and y (peak areas) values. Therefore, the standard curves could be used for the determination of corresponding unknown concentrations given their peak areas. 3.0 CHAPTER 3: Organic (Normal) solvent Extraction 3.1.0 Objective and Procedure The main objective of this extraction process is to obtain a light coloured Product with a high recovery rate of the six pyrethrin active ingredients [Kiriamiti et al. 2003]. Extraction essential components with an organic solvent is the simplest, commonest and most importantly, economic technique in modern Chemical industry Wikipedia. The desired samples are submerged completely and agitated in an organic solvent. This agitation (with or without heat) helps to dissolve the desired compounds needed. Hexane, dimethyl ether, methanol, ethanol are some of the most common organic solvents used for these kinds of extractions. However, not only the desired components are extracted during this process. Other soluble substances (waxes and pigments) that are hydrophobic are also extracted. The solvent is removed from the extract by vacuum processing at lower temperature, for re-use. The process can last for hours or weeks, or even more. After the solvent removal, the waxy thick mass left is the concrete. This is composed of essential oils and other oil soluble (lipophilic) materials (Wikipedia). The concrete is too thick (viscous), coupled with the presents of undesired components; to be used directly. A further treatment, usually with another solvent that only dissolve the desired compounds from the concrete is necessary. This solvent is again removed leaving behind the absolute (substance). 3.2.0 Sample Preparation For all chemical analyses, the analyte to be measured must be in a sufficient quantity and in a suitable form for the GC analysis. Usually, samples require pretreatment. This has an influence on the end result. Sample preparation is therefore an essential step in analysis just as measurements. Then appropriate extraction methods are employed. A 100g of the grounded chrysanthemum material containing the desired analytes was weighed out and placed inside a 500mL round bottom flask and a bottle of normal Hexane (as extraction solvent) was poured in to submerge the sample completely. This was then transferred into a water bath. The set up was then equipped with a condenser, to condensate the liquid vapour and connected to water source. The temperature program was set and the system was heated at various temperatures (40 oC, 50 oC, 60oC and 70 oC) each at times 5hrs and 7hrs. Magnetic stirrers were used to maintain equal distribution of heat and solvent and the rotation was set at 20rpm in each case. Each solution was filteredfilter paper-7cmwith the aid of a rotary evapourator after the set time and the extracted solid discarded. The filtered solution was condensed to 10ml each with a rotary evapourator to remove the solvent. This system has the advantage that the solvent is repeatedly recycled and also the temperature can be controlled (since the sample is thermo labile). Each concentrated sample was thereafter, filtered (0.45m) and 0.1L of each analysed in the GC. The results are below. Cp Art 40C (5Hrs) 50C (5Hrs) 60C (5Hrs) 70C (5Hrs) t A t A t A t A C1 19.91 20.88 23270.3 20.24 5483.71 20.25 5039.21 20.30 5921.06 J1 23.13 23.80 10711.0 23.33 3043.60 23.33 2753.30 23.39 3258.92 P1 24.43 25.44 19810.3 24.86 8830.62 24.87 7989.68 24.95 8956.26 C2 38.57 39.55 4121.32 39.16 3328.70 39.19 3132.16 39.35 3767.63 J2 42.09 42.289 1125.67 42.23 2075.81 42.25 1956.50 42.29 2505.47 P2 42.96 43.237 215.407 43.18 329.54 43.20 304.55 43.25 1030.98 Ttl 191.09 190.27 389.82 193.01 23091.95 193.09 21175.4 193.53 25440.32 Table 4: results for 5hrs analysis Cp Art 40C (7Hrs) 50C (7Hrs) 60C (7Hrs) 70C (7Hrs) t A t A t A t A C1 19.91 20.19 4175.84 20.13 3015.38 20.16 3069.10 20.96 21666.50 J1 23.13 23.31 2341.50 23.27 1642.98 23.32 1651.68 23.87 10253.00 P1 24.43 24.80 6795.98 24.72 5034.69 24.76 4946.84 25.51 18905.40 C2 38.57 39.08 2675.11 38.98 1841.87 39.06 1896.36 39.73 3905.71 J2 42.09 42.21 1638.08 42.18 1097.48 42.22 1206.58 42.34 1616.78 P2 42.96 43.16 284.72 43.11 182.52 43.15 187.01 43.28 167.43 Ttl 191.09 192.75 17911.23 192.39 12814.92 192.7 12957.57 195.69 56514.82 Table 5: results for 7hrs analysis The average elution time for each analyte was calculated within each time frame. Component Standard sample At 5hrs At 7hrs Cinerin 1 19.91 20.43 20.36 Jasmolin 1 23.13 23.46 23.44 Pyrethrin 1 24.43 25.03 24.95 Cinerin 2 38.57 39.31 39.21 Jasmolin 2 42.09 42.26 42.24 Pyrethrin 2 42.96 43.22 43.18 Total 191.09 193.71 193.38 Table 6: average retention times With the peak areas from Table 4, the concentrations and yields for PYI and PYII within these times was calculated as well. Concentrations (mg/ml) Num Comp Pyret Stand 5hrs 7hrs 40 50 60 70 40 50 60 70 1 C1 PYI 9.27 1175.54 379.33 344.90 396.34 290.94 211.83 211.27 1110.71 2 J1 3 P1 4 C2 PYII 7.76 247.65 259.97 244.51 331.15 208.46 141.52 149.16 257.96 5 J2 6 P2 Total PY 17.03 1423.19 639.30 589.41 727.49 499.40 353.35 360.43 1368.67 Table 7: concentrations of PYI and PYII Yields Num Comp Pyreth Stand 5hrs 7hrs 40 50 60 70 40 50 60 70 1 C1 PYI 0.46 1.18 0.38 0.34 0.40 0.29 0.21 0.21 1.11 2 J1 3 P1 4 C2 PYII 0.38 0.25 0.26 0.24 0.33 0.21 0.14 0.15 0.26 5 J2 6 P2 Total PY 0.85 1.42 0.64 0.59 0.73 0.50 0.35 0.36 1.37 Ratio (PYI : PYII) 1.21 4.75 1.46 1.41 1.20 1.38 1.50 1.40 4.27 Table 8: yields and ratio for PYI and PYII The areas of PYI and PYII for the various temperatures from the analysis (Tables 4 and 5), gave higher concentrations (Table 7). These exceeded the range set for the standard. The range for PYI is 9.27mg/ml and that of PYII is 7.79mg/ml. Yet the lowest concentrations for PYI and PYII (Table 7) are 211.27mg/ml and 141.52mg/ml respectively. The total PY concentration in the standard (range) is 17.03mg/ml and the highest PY concentration from the analysis (extractions) is 142.32mg/ml (since PYI and PYII have the same volume, their concentrations could be added). Therefore, and for accurate results, these concentrations should be diluted (mix with more solvent) to fit into the range before proceeding with the analysis. This can be done by ways: 1) Finding the Dilution Factor. This in a way will tell how many times the initial volume (before the analysis) should be diluted to fit into the range. For such cases, the concentrations gotten from the reading on standard curve should be multiplied by the dilution factor. Therefore, the dilution factor, Df = final concentration/initial concentration (6) The final concentration is 1423.19mg/ml and the initial concentration is 17.03mg/ml Therefore, Df = 1423.19(mg/ml)/17.03(mg/ml) Df = 83.56958 This show a that the initial concentrated volume of 10ml should be multiplied almost 84 (i.e. about 850ml) times. This is too much solvent to use, hence not economical. 1) By taking a portion (aliquot) of the concentrated concrete and diluting it with an amount of solvent. The concentration of the concentrated concrete, Cc = 142.32mg/ml and that of the diluted concrete is Cd. The volume of the concentrated concrete taken is Vc and that of the dilution targeted is Vd Using the dilution equation Cc * Vc = Cd * Vd.. (7), the diluted concentration, Cd can be calculated. Cc = 1432.19mg/mL, if Vc = 1mL and Vd = 50mL. Cd = ? Cd = 1432.19 x 1 / 50 (mg/mL) = 14.3219mg/mL This new diluted concentration falls within the range of 17.03mg/mL Therefore, after concentrating the extract to 10mL, 1mL aliquot is moved into a 50mL flask and solvent topped to the mark before the GC analysis. 2) Eliminating the use of the rotary evapourator. Since a bottle of Hexane (500mL) is used for the extraction each time, it is not necessary to concentrate the solution after filtration but top up with some hexane to 500mL (some hexane will escape during the extraction process) mark before the GC analysis. 3.3.0 Optimum Extraction Temperature Table 8 shows the extraction temperatures and the corresponding yields between 5hrs and 7hrs. The result in this case suggests that the optimum temperature is at 40oC. This is because pyrethrins are thermo labile and therefore degrade after 40oC [E. Stahl, 1998; C. Gourdon, 2002; W.H.T.Pan, 1994]. At 40oC, targeted PY components are extracted more but after this temperature (with the increase) more undesirable components are extracted at the expense of the pyrethrins components which decompose. Again, at 40oC 5hrs gave a better yield than 7hrs. This suggests that with prolong heating, even at a safer extraction temperature (40oC), the PY yield is affected negatively. Therefore, an investigation into the optimum time and yield at this temperature (40oC) was done and the results, by fitting into the concentration range this time, before GC analysis are below: Num Comp Pyret Stand 40oC 3hrs 4hrs 5hrs 6hrs 1 C1 PYI 9.27 4.23 5.72 3.77 3.59 2 J1 3 P1 4 C2 PYII 7.76 1.03 1.81 0.83 0.70 5 J2 6 P2 Total PY 17.03 5.26 7.53 4.60 4.29 Table 9: Concentrations at various times at 40oC The results show that the concentrations are fitted into the range such that all the concentrations less than the maximum range set (17.03). Even more, they are within half of the range. This is important because the errors in the concentrations will be minimal if the signal (area) from the unknown lies in the middle of the signals (areas) of all the standards (chromatography online). Num Comp Pyreth Stand 40oC 3hrs 4hrs 5hrs 6hrs 1 C1 PYI 0.46 2.12 2.86 1.88 1.80 2 J1 3 P1 4 C2 PYII 0.38 0.52 0.90 0.41 0.35 5 J2 6 P2 Total PY 0.85 2.64 3.76 2.29 2.15 Ratio (PYI: PYII) 1.21 4.10 3.16 4.56 5.15 Table 10: Yields and ratio of PYI and PYII 3.4.0 Results and Discussions The percentage yields I obtained are not out of place comparing with literature. In some cases, the yield of PY varies from 0.91 to 1.30% of the dry weight [Kolak et al., 1999; Casida and Quistad, 1995]. According to Bakari (2005), the yield is between 0.60 0.79%. Bhat (1995) reported content ranging from 0.75 to 1.04%. However, Morris et al. (2005), reported yields of approximately 1.80 to 2.50%. Still according to Kiriamiti et al. (2003) the yield ranges between 0.50 and 2.0% while Pandita and Sharma (1990) gave yields varying from 0.90 to 1.50%. Above all Casida and Quistad (1995) states that it is possible to obtain pyrethrin yield of 3.0% or more. Therefore, the yield from my analysis of 0.85 to 3.76% conforms to literature. From this analysis, the optimum extraction conditions with Hexane are at 40oC in 4 hours (yield 3.76) but is this the real optimum extraction conditions (especially the temperature)? Since PY does not decompose between 20oC and 40oC, is it possible to have the optimum temperature at 25oC, 30oC or even 35oC? With this in mind, a further investigation was carried out in the same time frame (4hrs) beginning with 30oC such that if the result gave more yield than the one at 40oC, then the next would be 25oC and possibly 20oC. On the other hand, if the result gave fewer yields then the next would be 35oC and possibly 45oC. This would confirm the optimum conditions for the extraction process. 3.5.0 Conclusion References 1) Wikipedia 2) chemical analysis book 3) www.chromatographyonline.com 5) B.W. Wenclawiak et al, 1997 6) Rosana, Vanessa, 2003; Analytica Chimica Acta 505 (2004) 223-226 7) Kolak et al., 1999; Casida and Quistad, 1995 8) Bakari (2005) 9) Bhat (1995) 10) Morris et al. (2005) 11) Kiriamiti et al. (2003) 12) Pandita and Sharma (1990) 13) Casida and Quistad (1995) 14) Journal of chemical education vol. 75, no. 9, September 1998 Pyrethrins are well separated on polar columns but their analysis with a conventional (normal) column takes about 1 h. This is unacceptable but with a short OV-1 column, analysis time is reduced and thermal decomposition is also drastically limited; since the residence time is shorter and the elution temperature of pyrethrins I and II is lower. [Recommendation] A cold-on-column injection system and a high constant flow rate can further reduce pyrethrin degradation and elution temperatures and as a consequence their isomerization. [Recommend]

What a 16 Personality Types Quiz Can Tell about You

Should you do what you feel pushed toward doing or should you follow you heart? The answer is so simple, it’s laughable! But what will people who do not know what they want to do in life choose from? Is their only option that of going off on the path laid down by life’s natural course, or try and fail a couple of times in an attempt to find out where they fit? Here is where a well drafted personality traits quiz comes in handy, saves time and heart break and gives those who were not born with a plan a chance at real happiness and personal accomplishments: the 16 personality types quiz! Who Invented the 16 Personality Types Model? Generated from the Jungian theories on types of personalities and expanding on his concepts on Introversion and Extraversion, Judging Functions and Perceiving Functions, the 16 personalities model was coined by Katharine Briggs and her daughter, Isabel Myers-Briggs. They used acronyms to define each personality type and their interest was more in the area of what combination of traits makes out a type, with a dominant function that â€Å"programs† a person for a certain role. How Does This Help You? Certainly you have taken a number of other quizzes as well, curious about your personality. But the results were usually pointing towards very inclusive categories with general definitions and not enough insight. This model is built bearing in mind the way in which all of your personality traits interact. This means that, far from a simple† you are an introvert an extrovert† rendering, it bears the fact that people can be included into other â€Å"in-between† categories. By taking this test, you too will fall in one category defined by an acronym such as ENFJ-T or ISTP-T and you will have a lot to learn about yourself from these simple letters. What Can You Find out by Taking This Quiz? In brief, test results take each candidate through the general profile, present strengths and weaknesses, insights on themselves in relation to family, friends and life partners and explain career patterns and workplace habits. They also give you an idea of what types of projects and tasks, or social situations you will fare better in. Why Should You Know about This Classification? It is always best to cultivate the natural abilities of each individual and to stop forcing impossible demands which only end up creating frustration and failure. For example, introverted and assertive types are better at working alone with full control over the environment and full trust on their skills. This already narrows down the list of jobs and projects. By knowing what you have to work with earlier in life, as a student, you will know better how to invest your time, manage situations and create opportunities where they are really possible. Finding out what your dominant functions are means knowing what you are better suited for. Who knows? You may even be so surprised at how well you are doing something, that you may even end up feeling like you are cheating, since you are naturally so good at it. Here’s a brief classification of the 16 personality types quiz. Which type fits your personality best? INFP (The Healer) – imaginative and idealistic. The Healer guides after their own set of beliefs and core values. They are compassionate, caring and sensitive; creative and incredibly artistic. INFJ (The Counselor) – intuitive and motivated. The Counselor has imaginative ideals, and they are incredibly compassionate, caring and sensitive. ENFJ (The Teacher) – driven and energetic. The Teacher has a vision. They see great potential in others, and they use their charisma to persuade others with ingenious ideas. ENFP (The Champion) – original and imaginative. The Champions are enthusiastic students who love to express their thoughts out loud. They use humor to engage others, and have excellent creative potential. INTJ (The Mastermind) – eager to improve themselves and come up with the best ideas. The Mastermind has deep analytical skills; they’re intellectuals who enjoy complex problem solving and logical reasoning. ENTJ (The Commander) – commanders are strategic leaders; they’re motivate to organize and they enjoy crafting complex plans to turn ideas into life-long goals. ENTP (The Visionary) – inspired innovators and motivated to come up with the best solutions; the Visionaries are clever and curious; they seek to understand the principles, the people and systems surrounding them. Unconventional and open-minded, the Visionaries are constantly aiming to influence, analyze and understand others. INTP (The Architect) – captivated by logical analysis and constantly preoccupied with theory, the Architects are detached and they like to spend time exploring new concepts, seeking understanding and making connections. ESFJ (The Provider) – sensitive to other people’s needs, the Providers are dedicated to cooperating with those around them. They value tradition and loyalty, and put their family and friends on the first place. ESFP (The Performer) – charming and engaging. The Performers like to entertain. They’re energetic, spontaneous and fun, and they love to communicate and be in the center of attention. ISFJ (The Protector) – loyal, compassionate and practical. The Protector is grounded and conventional. They have a deep sense of liability and focus on completing duties ISFP (The Composer) – gentle caretakers and rather quiet, the Composers are friendly and warm. They’re flexible, easy to talk to and spontaneous, and they see beauty in everything that surrounds them. ESTJ (The Supervisor) – hardworking and commanding. The Supervisor is the perfect leader. They love to rule, and they value predictability and methodology. ESTP (The Dynamo) – extremely energetic, the Dynamos are thrill seekers; they love interacting with people, and they have the greatest sense of humor. ISTJ (The Inspector) – responsible and extremely organized, The Inspector is neat and ordered. They are reliable and love to follow the rules. ISTP (The Craftsman) observant artisans, adaptable and independent. The Craftsmen are extremely attentive to details; they are reserved and attentive, and they enjoy taking action and express their thoughts loud and clear. Well, found someone familiar?

Problems With Drinking Water Supplies in Kenya Essay example

Water is a bare necessity both for the survival of an individual and a nation. Freshwater scarcity has become a global concern as the projected worldwide demand on water exceeds supplies. Less developed countries in particular are currently suffering from severe water shortages and water contamination. #8230;half the population of our civilized world suffers today with water services inferior to those of the ancient Greeks and Romans#8230;In many developing countries, cholera, dysentery, and other water related diseases are on the upswing. (Gleick,1999) Kenya, Africa is one such case. Kenyas population is approximately 105,000, with a high infant mortality rate and an average life expectancy of 58. Average water conditions†¦show more content†¦Most crops are harvested in poor soil and produce low yields, providing inadequate nutrition and food supplies. Poverty and poor education contribute to the problem. Farmers are in very disadvantageous economic conditions to impr ove their land or equipment. The people of Kenya prove to have very little education on hygiene, bacteria, or water born viruses. Government inefficiency is contributing to the problem. Although the Kenyan legislature has instituted the National Irrigation Board, the agency is weak and fails to effectively enforce regulations on consumption and pollution. It is estimated that 80% of current water abstractions have no permits and inspectors rarely monitor those that do. Also, Kenya is not a member of any convention that deals with waters shared across national boundaries. However, government efforts are currently being made to improve the situation in Kenya. The Lake Naivasha Riparian Owners Association is working on an environmental management plan. Steps have been taken to promote more advanced agricultural techniques such as intercropping and soil and water conservation. Proper uses of agrochemicals are being encouraged along with development of organic farms, which are less environmentally threatening. Outside agencies such as PLAN International are making huge progressive developments in Kenya. PLAN is working with issues of water shortages, poverty, and poor health by assisting communities financially andShow MoreRelatedComparing Different Ways of Supplying Water to Kenya1516 Words   |  7 Pagesdifferent ways to supply water in this region. At the end of the report, make a recommendation of the best method of water provision. 1. Introduction Water is one of the vital substances on earth and according to Kreger (2004)â€Å"Actually, only 1% of the worlds water is usable to us. About 97% is salty seawater, and 2% is frozen in glaciers and polar ice caps. Thus that 1% of the worlds water supply is a precious commodity necessary for our survival.† All humans on earth need water to survive. ARead MoreThe Severe Water Crisis Of Africa Is One Of The World s Leading Problems1145 Words   |  5 PagesThe severe water crisis in Africa is one of the World’s leading problems. Kenya and South Africa have always had limited water resources, and now with their population continuing to grow, an increase in the demand for water is needed now more than ever before. Water plays a crucial role in continuing to help the continent of Africa develop and grow. This lack of water affects food security, impoverished people, and their health. Imagine spending one-third of your day collecting water from the nearestRead MoreWater Scarcity Of Ethiopia And Water Sanitation842 Words   |  4 PagesOn 28 July 2010 the human right to water was clearly accepted by the United Nations General Assembly. Clean drinking water are essential to the realization of all human rights were also been acknowledged (United Nations, 2014). The human right to water include five factors which are sufficient, safe, acceptable, physically accessible and affordable (United Nations, 2014). However, in these five factors, sufficiency and safety are the top two serious issues which will be discussed in this reportRead MoreGlobal Climate Change On Natural Disasters And Agricultural Production1308 Words   |  6 PagesHuman well-being is fundamentally dependent on ecosystems for the provisioning, cultural and regulating services that they provide (World Bank, 2007). Clean water is one of the critical resources provided to man by ecosystems. As such, t he ecosystem concept has been elevated as a fundamental attribute for human development. Maintenance and access to ecosystem services has consistently been associated with better health and economic outcomes. Human health risks originate from traditional forms ofRead MoreChesilot Water Project Essay1569 Words   |  7 Pagescommunity. In this paper, I will review the Chesilot Water Project, one of the successful community based programs explored in Were’s â€Å"Local Organization and Gender in Water Management: A Case Study from the Kenya Highlands.† Kenya is one of the most water scarce countries in Africa and the world. Therefore, there are many areas with inadequate access to safe and sufficient water. The WHO estimates that only 12% of rural Kenyans have household water connections (WHO/UNICEF, 2004). During the 1980’sRead MoreWater Scarcity in History1668 Words   |  7 PagesNatural ecosystems require water for the survival of the plants and animals that live within them. These ecosystems help to regulate water quality and quantity of water. Wetlands hold water in periods of high rainfall, slowly releasing it during dryer periods, and purify it of heavy metals and other contaminants. Forests recharge our groundwater, which can be used elsewhere for drinking or irrigation. (Bergkamp 1) Natural ecosystems can help to prevent floods, provide shelter and millions of peopleRead MoreThe Unfortunate Reality Of Africa s Water Problem1109 Words   |  5 PagesThe Unfortunate Reality of Africa’s Water Problem Intro, statistics- Water scarcity is defined as the lack of sufficient water resources to meet the demands of usage in different regions. Worldwide, 782 million people lack access to safe and sanitary water, 37% of those people live in Sub-Saharan Africa. According to World Health Organization (2006), in 2004, only 16% of those in Africa had access to drinking water through a household connection. According to an estimation done by the United NationsRead MoreAbout Transnational company1249 Words   |  5 Pages Should the Kenyan Government encourage TNCs to invest in Kenya? Globalization is the process by which businesses or other organizations develop international influence or start operating on an international scale (Capital, 2013). Globalization has increased the production of goods and services, for instance the biggest companies are no longer national firms, but transnational corporations  with subsidiaries in many countries. Transnational Corporations (TNCs) are companies with branches in manyRead MoreKenya Water Crisis1862 Words   |  8 PagesWater crisis in Kenya Ygnacia Bradford October 12, 2010 An increasingly serious drought continues to plague the county of Kenya effecting the environment and numerous ways. The Population, Health Risks Disease The typical day for a rural Kenyan family, usually children, who should otherwise be in school, walk several miles to search for water to provide for the family for cleaning, and food preparation. Most times the water is dirty, not treated or which is contaminated by surfaceRead MorePoverty And Its Effects On African Nation1353 Words   |  6 Pagestotalitarian regimes. Having large debts result in little to no money being used for social service, such as education, pensions or medical care. The African nation is pushing for debt relief, because they are unable to maintain payments. This problem does not affect other nations as much like Nigeria but it does take a toll on the smaller nations and the large debtor nations. There are large amounts money being used in Africa for developments of mega projects. Ghana is the richest country in Africa

27 Ways to Use the Verb Fare in Italian

The verb fare, which in English means to make, do, prepare, execute, or carry out—say, make your bed or do your homework or make pasta—is one of the richest, most versatile verbs in the Italian language. Its used to express a nearly boundless array of actions, from standing in line to making friends, buying oneself a new car, taking a walk, or taking a trip. And, of course, the weather. The Latin derivation of the verb fare—from facere—weighs heavily on the verbs conjugation, making it a most irregular second-conjugation verb. In fact, fare heads up its own model and family of irregular and pesky verbs that derive from fare—a topic all of its own. Here, though, we want to tell you about the myriad purposes of fare. They are more than curious idioms or phrases: They are staple expressions of everyday actions and sentiments—many of them creative and interesting, displaying the full color of the Italian language—that you will want to understand and use. Idioms With Fare Here are some of the most common expressions of actions that use fare in Italian. They are transitive and conjugate with avere: fare il biglietto to purchase a ticket fare la fila/la coda to stand/wait in line fare la spesa to go grocery shopping fare lo shopping/le spese to go shopping fare ginnastica/sport to exercise/do sports fare forca/chiodo to play hookey fare una domanda to ask a question fare una fotografia to take a picture fare una passeggiata to take a walk fare un giro to go for a ride or a stroll fare colazione to have breakfast fare un viaggio to take a trip fare il bagno/la doccia to swim or bathe/to take a shower fare un capello in quattro to split hairs fare castelli in aria to daydream fare finta to pretend fare il possibile/di tutto to do everything possible fare del proprio meglio to do one's best fare amicizia to make friends fare alla romana to split the check fare il pieno to fill up the gas tank fare la pipà ¬/fare i bisogni to tinkle/go to the bathroom fare il callo to get used to something negative fare la bocca to get used to something good fare confusione to make noise/create confusion fare da sà © to handle something on one's own fare danno to cause damage fare festa to take the day off fare lo stupido/il cretino to act stupidly fare il bravo to act nicely fare attenzione to pay attention fare male/fare bene to harm/do good (or act wrongly or rightly) fare fatica to struggle fare tardi/presto to be late/early fare in tempo to manage to do something on time fare fronte a to face something (figuratively) fare bella/brutta figura to look good/bad/make a good or bad impression fare a meno to do without something fare torto a qualcuno to wrong someone fare a botte to brawl fare piacere to please fare schifo to be gross or disgusting fare colpo to impress/make a nice showing fare impressione to shock (negatively) fare buon viso a cattivo gioco to smile or play along with someone's deception or bad intent Expressions With Farsi In these uses, fare is used in reflexive mode or otherwise intransitive mode. You conjugate with essere: farsi la barba to shave farsi i capelli to cut one's hair or get one's hair done farsi coraggio to hearten oneself/give oneself courage farsi in là   to move over farsi in quattro to bend over backwards farsi vivo/a/i/e to get in touch farsi largo to push through a crowd farsi bello/a/i/e to primp farsi un nome to make a name for oneself farsi valere to assert oneself farsi conoscere to make oneself known farsi notare to draw attention farsi il segno della croce to make the sign of the cross farsi capire to make oneself understood farsi pregare to make someone beg farsi vento to fan oneself farsi desiderare to make someone wait farsi gli affari propri to mind one's business farsi la macchina, la casa nuova to buy oneself something (a car, a new house) farsi male to hurt oneself Other Important Uses of Fare Fare has some other important uses in conjunction with other verbs or acting in the place of other verbs: Lasciare fare to let something be/leave something alone Lascia fare; dopo faccio io. Leave it; I will take care of it later. Avere a che fare to have (or not) something to do with something or someone Non ho niente a che fare con Luca. I have nothing to do with Luca. Darsi da fare to work hard at something Mi do da fare ma non trovo lavoro. I am working hard at it but I can't find a job. Saperci fare to know how to do something well Quel ballerino ci sa fare. That dancer knows what he's doing. Far fare qualcosa a qualcuno to make someone do something La mamma mi fa sempre fare le pulizie. Mom always makes me clean. Fare vedere to show someone something Mi fai vedere il tuo vestito nuovo? Will you show me your new dress? Fare sà ¬ che to make it so as to make something happen La mamma ha fatto sà ¬ che non fossi a casa quando hanno portato la macchina nuova. Mom made it so I would not be home when they delivered my new car. Fare (un lavoro) to have/do a profession La Lucia fa la maestra. Lucia is a teacher. Fare (come bastare) to last/to suffice Questa acqua farà   per due giorni. This water will last for two days. Fare (come cogliere/tagliare) to cut or pick La signora à ¨ andata a fare l'erba per i conigli. The woman went to cut grass for her rabbits. Fare (come dire) to say (to go, informally) Ho visto e Andrea e mi fa, "Mi presti dei soldi?" I saw Andrea on the street and he goes, "Would you loan me some money?" Fare passare to let someone by Fammi passare! Let me by! Fare da mangiare to cook Oggi ho fatto da mangiare. Ho fatto una minestra. Today I cooked. I made a soup. The Weather: Il Tempo The verb fare is used in many expressions relating to the weather. The weather—it, third-person singular, spoken or unspoken—is the subject, making cold, hot, or snow. Che tempo fa? How is the weather?Oggi fa bello. Its beautiful today.Domani fa cattivo tempo. Tomorrow its going to be bad weather.Questa settimana ha fatto caldo. Its been hot this week.Qui fa sempre freddo a gennaio. Its always cold here in January.In primavera fa sempre fresco. In spring, its always cool.Domani fa la neve. Tomorrow its going to snow. Proverbs Using Fare Of course, because the verb fare covers so many actions, it is used in a number of proverbs or sayings about everyday life. Tra il dire e il fare cà ¨ di mezzo il mare. There is a big difference between words and actions.Chi non fa non falla. Those who dont do anything dont make mistakes.Chi fa da sà © fa per tre. If you want something done, do it yourself.Non fare agli altri cià ² che non vorresti fosse fatto a te. Treat others as you want to be treated.Tutto fa/tutto fa brodo. Every little bit helps.Chi non sa fare non sa comandare. A bad worker is a bad master.

Analysis Of Martin Luther King Jr. - 1308 Words

â€Å"If we are to have peace on earth, our loyalties must become ecumenical rather than sectional. Our loyalties must transcend our race, our tribe, our class, and our nation; and this means we must develop a world perspective,† said Martin Luther King Jr. No other race of people on earth have been persecuted and oppressed more than the Jews. This persistent reality of their history is a sharp reminder that history does repeat itself and it’s not always beneficial. During the Roman Empire in the first century of the Common Era, we see both Caesar Augustus and Tiberius treat the Jews favorably to the extent of giving them imperial protection. This was not an unusual gesture because the Romans were pantheistic worshipers and were more liberal†¦show more content†¦In Egypt, Umar returned power to the Bishop of Alexandrea who was a fugitive during roman rule. The Bishop said, today I witness in this city of Alexandria, salvation and contentment reigning after a long period of persecution by the Roman Rulers.† http://eng.dar-alifta.org/foreign/ViewArticle.aspx?ID=543 During the reign of the Catholic kings in Spain, after the fall of the romans between 586 to 711 C.E., there was an increased persecution of the Jews. King Recceswinth’s conversion from Arianism to Catholicism brought about a sudden piety in his faith combined with anti-Jewish sentiments. He formally issued laws forgiving the debts of all the Christians who he claimed were being oppressed by the Jews. This situation was brought about because the Jews were successful entrepreneurs and tradesmen and had accumulated significant property and wealth to such a degree, that they owned nearly a third of the empire making the reigning monarch uneasy. The Christians being forbidden to charge taxes, had no incentive of profit to be part of the trade. The Jews however, did and ended up not only wealthy but owning Christian servants who could not pay back their debts. They even ended up with collateral from the churches that borrowed for them. This economic and social discrepancy was reason enough for the then monarch to enforce an unjust law, forcing them to convert toShow MoreRelated Analysis of Letter from Birmingham by Martin Luther King Jr.937 Words   |  4 PagesAnalysis of Letter from Birmingham by Martin Luther King Jr. Martin Luther King Jr., is one of the most recognized, if not the greatest civil rights activist in this century. He has written papers and given speeches on the civil rights movement, but one piece stands out as one of his best writings. â€Å"Letter from Birmingham† was an intriguing letter written by King in jail in the city of Birmingham, Alabama. He was responding to a letter written by eight Alabama Clergyman that was publishedRead MoreEssay on Critical Analysis of Martin Luther King, Jr.s Speech1674 Words   |  7 PagesCritical Analysis of Martin Luther King, Jr.s Speech Introduction In this critical analysis I am going to look at Martin Luther King, Jr and the I have a dream speech. Martin Luther King, Jr is very distinguished due to the many outstanding achievements he accomplished throughout his life. He was an American clergyman and he accomplished the Nobel Prize for one of the principal leaders of the American civil rights movement. Kings defiance to segregation andRead MoreAnalysis of Martin Luther King Jr.s Letter from Birmingham Jail962 Words   |  4 Pagesintangible, it is still necessary. Some forms of inspiration come as passionate love while others appeal as injustice. Martin Luther King Jr.s Letter from Birmingham Jail was a response to A Call for Unity by eight white clergymen. His inspiration for writing the letter was the clergymens unjust proposals and the letter allowed him to present his rebuttal. Martin Luther King Jr. effectively crafted his counter argument by first directly addressing his audience, the clergymen, and then using logosRead MoreSociological Analysis of Martin Luther King, Jr.’s Letter from a Birmingham Jail1214 Words   |  5 Pagesï » ¿ Sociological Analysis of Martin Luther King, Jr.’s Letter from a Birmingham Jail Abstract The paper analyses Martin Luther King, Jr.’s â€Å"Letter from a Birmingham Jail† from a sociological point of view and shows how three major theories (structural functionalism, social conflict, and symbolic interactionism) are treated in the letter. The paper shows different appreciation of King’s ideas and works by his contemporaries and modern people. It also explores the concepts of â€Å"nonviolentRead MoreAnalysis of Martin Luther King Jr. Warrior for Peace by Tanya Savory848 Words   |  4 Pages racism was very powerful and the white people were the most stronger people in the communities, however, it was only in some states of the United States Of America. In others the racism did not existed, for example according to the book â€Å"Martin Luther King Jr. Warrior For Peace†by â€Å"Tanya Savory† in one of the states that there was no racism was Connecticut. During the winter of 1928, in Montgomery, Alabama, a black girl who was only fifteen-year-old got on a city bus so she could go visitRead MoreAnalysis of Martin Luther King Jr. ´s Letter From Birmingham Jail771 Words   |  3 Pagesagainst the prejudice that they have to face, accomplish justice that every single one of them are fighting for. Dr. Martin Luther King, a leader of the protest against prejudice was able to pursue the rights for African American people. However eight of his fellow clergymen criticized his procedure to protest, but they still supported him. In the Letter from Birmingham Jail, King wanted to encourage others to rebel against the wrong, even if it is not wise it is right, he was optimistic and yetRead MoreRhetorical Analysis Of I Have A Dream Speech By Martin Luther King Jr.815 Words   |  4 Pagessteps of the Lincoln Memorial more than two score years ago, Dr. Martin Luther King electrified America with his momentous I Have a Dream speech. Ai med at the entire nation, King’s main purpose in this speech was to convince his audience to demand racial justice towards the mistreated African Americans and to stand up together for the rights afforded to all under the Constitution. To further convey this purpose more effectively, King cleverly makes use of the rhetorical devices — ethos, pathos andRead MoreAn Analysis of Jonathan Swift and Martin Luther King Jr.’s Stylistic Devices2370 Words   |  10 PagesBirmingham Jail Martin Luther King Jr. has two different audiences. First he addresses the eight clergymen who wrote him the original statement posing a few questions they would like him to answer. But more importantly he writes to the white moderate, in particular those who are â€Å"lukewarm† on the issue at hand, segregation. These â€Å"lukewarm† people do not have a solid opinion either way, they merely â€Å"sit on the fence† waiting for some one to persuade them. Similar to Swift, King uses parallel structureRead MoreRhetorical Analysis of the I Have a Dream Speech by Dr. Martin Luther King Jr.1219 Words   |  5 Pagesechoed throughout Washington D.C. August 28, 1963 as Martin Luther King Jr. paved the path to freedom for those suffering from racial segregation. It was the day of the March on Washington, which promoted Civil Rights and economic equality for African Americans. In order to share his feelings and dreams with the rest of the nation, Martin Luther King Jr. gave his speech encouraging all to overcome racial segregation. Martin Luther King Jr.’s I Have a Dream speech was very effective due to theRead MoreAnalysis of Dr. Martin Luther King, Jr.s I Have A Dream Speech619 Words   |  3 Pages28, 1963, Dr. Martin Luther King Jr. delivered one of the most famous speeches of all time to an audience of more than 200,000 civil rights supporters on the steps of the Lincoln Memorial. In his, â€Å"I have a dream† speech, King addressed his encouragement of white and black people working together to achieve racial peace and harmony. He especially wanted to teach the young blacks that equality could be gained through the use of non-violence. The main reason King used nonviolence

History of Emirates Airlines Free Essays

string(86) " company moves into the new multi – million dollar Emirates Group Headquarters\." The story of a firm whose success story is intertwined with the incredible development of Dubai could be nothing but fascinating. Against a backdrop of regional unrest and volatile global economies, progress has been maintained at a rapid pace in every year of Emirates’ and dnata’s existence. A combination of business acumen, ambition and savvy investment set in motion a series of events which have propelled Emirates and dnata to amongst the most respected and recognized brands in the world. We will write a custom essay sample on History of Emirates Airlines or any similar topic only for you Order Now The story of a firm whose success story is intertwined with the incredible development of Dubai could be nothing but fascinating. Against a backdrop of regional unrest and volatile global economies, progress has been maintained at a rapid pace in every year of Emirates’ and dnata’s existence. A combination of business acumen, ambition and savvy investment set in motion a series of events which have propelled Emirates and dnata to amongst the most respected and recognized brands in the world. 2012 Emirates join Boeing in Seattle to celebrate the unveiling of its 1,000th 777. The landmark aircraft becomes the 102nd to join Emirates’ Boeing 777 fleet. Rio de Janeiro, Buenos Aires, Dublin, Lusaka, Harare, Dallas, Seattle, Ho Chi Minh City, Barcelona, Lisbon and Washington join the Emirates network, while a cargo-only service launches to Liege. Dnata acquires a majority stake in Travel Republic, the largest privately owned online travel agency in the UK, representing one of the biggest transactions in the company’s history. Marhaba celebrates its 20th anniversary and unveils new look. In tennis, Emirates becomes the Official Airline of the US Open and title sponsor of the Emirates Airline US Open Series. Emirates become the Team Sponsor of cricket’s Indian Premier League side Deccan Chargers. 2011 Emirates places the largest single order in Boeing’s history – 50 777-300 ER aircraft, worth $18 billion in list price. The order also included 20 777-300 ER options valued at US$ 8 billion. The Emirates Group posts a record profit of AED 5. 9 billion (US$1. 6bn) for the financial year Basra, Geneva, Copenhagen, St Petersburg and Baghdad are added to the Emirates network, while a cargo-only service is launched to Erbil. Shanghai, Johannesburg, Munich and Rome are added to Emirates’ A380 network. Emirates become the Partner and Official Airline of Real Madrid. Emirates and the Victoria Racing Club announce a new five-year sponsorship agreement. Emirates SkyCargo completes its first 100 per cent paperless freighter flight between Nairobi and Amsterdam. Emirates agree to sponsor the ‘Emirates Air Line’, a cable car across London’s River Thames. Aero Mobile, Emirates’ inflight mobile phone service provider, reaches its five millionth user and Emirates launches Wi-Fi internet connectivity for its A380 fleet. Dnata unveils a new company philosophy and fresh visual branding. Dnata announces a global investment of US$70 million in new equipment and facilities. dnata acquires a 50 per cent interest in Wings Inflight Services, a South African catering services provider. 2010 Emirates celebrate its 25th anniversary marking a quarter of a century of success and remarkable growth. New routes to Tokyo, Amsterdam, Prague, Al Medinah al Munawarah, Madrid and Dakar launch, while cargo-only operations to Almaty, Bagram and Campinas commence. The Emirates Group posts an increased profit of AED 4. 2 billion (US$1. 1bn) for the financial year ending 31 March 2010. Emirates orders 32 additional A380s at the Berlin Air Show along with GP7200 engines by Engine Alliance. It also orders 30 additional B777-300ERs at the Farnborough Air Show. Emirates are part of celebrations in South Africa an Official Partner of the FIFA World Cup. Emirates SkyCargo operates the first paperless flight between Mauritius and Dubai with all shipments carried processed electronically. Emirates SkyCargo sets a new record by operating the longest ever non-stop freighter flight of 17. 5 hours between Sydney and New York. Dnata acquires Mercator Asia in Thailand, its first overseas IT subsidiary. Dnata ground handling welcomes the first commercial flight to land at the new Dubai World Central – Al Maktoum International. Dnata officially opens its ‘baggage hub control center’ across all three terminals at Dubai International Airport. Dnata becomes the 4th largest catering provider worldwide by acquiring Alpha Flight Group Ltd. 2009 Dnata acquires two of the UK’s leading ground-handling operations at London Heathrow Airport and Manchester Airport. Dnata opens Afghanistan’s first internationally recognized one stop travel shop in the country’s capital, Kabul. Emirates launches flights to Durban and Luanda. Emirates begin operations of the Airbus A380 on the Sydney, Auckland, Bangkok, Toronto and Seoul routes. Emirates becomes the world’s largest operator of Boeing 777s with the delivery of its 78th B777 aircraft. Wolgan Valley Resort Spa, Australia’s first conservation-based resort and Emirates Hotels Resorts’ first property outside of Dubai, welcomes its first guests. Arsenal Soccer Schools Dubai – a joint venture between Emirates and Arsenal – opens its doors. Dnata marks its 50th anniversary at the Dubai Airshow. Al Maha Desert Resort Spa celebrates its 10th anniversary. Skywards, with more than five million members, marks its 10th anniversary with a new look and an enhanced Program. Premier Inn, a joint venture between the Emirates Group and Whitbread plc. opens its second hotel in Dubai at Silicon Oasis. The millionth Emirates passenger uses their own mobile phone on an aircraft equipped with the AeroMobile system. The largest ever Emirates’ TV advertising campaign to date – â€Å"Meet Dubai† – airs around the world. Emirates opens its Community Health Education Society (CHES) home for HIV-positive children in Chennai, India. 2008 Dnata acquires a 23% share of worldwide corporate travel company, Hogg Robinson Group (HRG), the largest share of the company, which gives dnata access to a network of 120 countries. dnata purchases a 49% share in Mind Pearl, a global contact center outsource organization, which sees dnata expand across three continents in their offering of contact center outsource solutions. Dnata’s cargo operation joins forces with Kanoo, UAE and SDV International Logistics, France to create one of the UAE’s largest logistics solutions providers, Freightworks. The company moves into the new multi – million dollar Emirates Group Headquarters. You read "History of Emirates Airlines" in category "Papers" The Emirates- dedicated Terminal 3 opens in October and within a month 500,000 passengers had flown out the terminal. Emirates SkyCargo begins operations out of Dubai Cargo Village’s new Mega Terminal, with a capacity to handle 1. 2 million tonnes annually. The first Emirates flight to Los Angeles touches down, while flights are also launched to San Francisco and Cape Town. Emirates becomes the first international carrier to introduce an in-flight mobile phone service. Emirates takes delivery of three A380s and aviation history is made when its first A380 touches down in New York. The 10,000th cabin crew member joins the Emirates team. New Emirates sporting facility 7he Sevens hosts record crowds at the Emirates Airline Dubai Rugby Sevens. 2007 Dnata enters the European market for the first time with the takeover of Jet Aviation Handling AG, the airport handling division of Swiss-based Jet Aviation Group. Emirates stuns the world by signing contracts for 120 Airbus A350s, 11 A380s and 12 Boeing 777-330ERs, worth an estimated $34. 9 billion, at the Dubai Air Show. New Engineering Centre and Engine Test Cell are officially opened. The Emirates Harbour Hotel Residence and the Marina Hotel open their doors. The addition of Sao Paulo to the network represents the first non-stop flight between the Middle East and South America. Emirates Flight Catering begins operations at its new $120 million facility at Dubai International. 2006 Emirates signs an agreement for 10 Boeing 747-8F in a deal worth $3. 3 billion. Emirates seals $195 million partnership deal with Fifa – the world governing body of football –and also buys the rights to screen every match played at the Germany World Cup on flights. Arsenal play their first match at the new Emirates Stadium. Sheikh Ahmed says Emirates is at the heart of Dubai’s Dhs300 billion investment in aviation and aerospace. Emirates SkyCargo signs $2. 8 billion order for 10 Boeing 747-8Fs. 2005 Emirates Group workforce totals 25,000 people from 124 countries around the world, making it Dubai’s biggest employer. Passenger traffic continues to rise with 12. 5 million recorded in the year. Emirates orders 42 Boeing 777s in a deal worth $9. 7 billion, the largest Boeing 777 order in history. 2004 Emirates orders four Boeing 777-300ERs, with nine options, in a $2. 6 billion deal. The SkyCargo fleet is increased with three Airbuses A310-300s added to its six Boeing 747s. Emirates makes its first flight to North America – a non-stop 14-hour flight to New York’s JFK Airport. This marked the first non-stop passenger service from the Middle East to North America, a continent which Mr. Flanagan described, in aviation terms , as the most important in the world. Emirates signs a ? 100 million deal with English Premiership side Arsenal, which includes naming rights to its new stadium for 15 years and shirt sponsorship for eight years, starting from the 2006/07 season. Dnata opens its first regional travel outlet in Kuwait. 2003 CAE and Emirates join forces to open the $100 million Emirates Aviation Training Centre which boasts numerous full-flight simulators. Emirates shocks the industry at the Paris Air Show with the biggest deal in civil aviation history – a staggering order for 71 aircraft at a cost of $19 billion. Daily service from Dubai to Sydney starts on the first A340-500 to join the fleet. The A340-500 features revolutionary ice in-flight entertainment system – including 500 channels in all classes, while every seat is equipped with a phone. After carrying 8. 5 million passengers, an increase of 26%, the airline posts an incredible profits increase of 94 per cent to Dhs907 million from Dhs468 million. Dnata is given a new corporate logo – a globe cushioned by a stylized runway represented by a curving green strip. 2002 Four million passengers vote in the Skytrax internet poll and Emirates is again named Airline of the Year. Global passenger levels drop by four per cent but Emirates figures rise 18. 3 per cent to 6. 8 million. Cargo across the world plunges nine per cent but Emirates enjoys an increase of 19. per cent to 400,000 tonnes. Group announces $275 million investment in new hangar complex at the Emirates Engineering Centre. 2001 Emirates SkyCargo Centre – with a capacity to handle 400,000 tonnes a year – opens. Emirates signs ? 24 million deal to sponsor English Premiership football club Chelsea for four years. In a survey of 2. 7 million airline passengers by Skytrax Research, Emirates was v oted Airline of the Year. Emirates takes delivery of its 18th Airbus A330-200 and orders two more, making it the biggest A330 operator in the world. With rivals reeling from September 11 and Boeing and Airbus in a weak bargaining position, Emirates stuns the world by announcing a $15 billion order for 15 A380s, eight A340-600s, three A330s and 25 Boeing 777s. 2000 The Sheikh Rashid Terminal opens, increasing the capacity at Dubai International to 22 million passengers a year. Frequent flyer loyalty programme Emirates Skywards is launched. Sheikh Ahmed announces Dubai Government is to invest $500-600m in the new Terminal 3 – with a capacity for 20 million passengers a year. Emirates becomes the first airline to sign up for the Airbus A380 when it orders seven, with an option on five more, at the Farnborough Air Show. Emirates buys another six Boeing 777-300s. Mr Flanagan is made a Commander of the British Empire. 1999 Emirates enters the hotel property market with the opening of the Al Maha Desert Resort Spa. The first of 17 new generations Airbus A330-200s arrive in Dubai. Emirates Group’s workforce totals 11,000. Dnata enters the South East Asian airport services market with the launch of dnata Philippines Inc. The airline capitalizes on the UAE’s growing ties with Australia and a deal is struck to add Sydney, Brisbane and Perth to the Melbourne route. Emirates sponsors the Melbourne Cup, the biggest meeting in Australia’s horse racing calendar, and the nation’s cricket team at the World Cup. The livery of the Emirates fleet is updated with a modern, dynamic design. Passenger arrivals at Dubai International hit the 11 million mark. 1998 Emirates increases its capacity by 26 per cent as passenger figures hit 3. 7 million, while cargo levels go up to 200,000 tonnes. Group takes a 43 per cent stake in Air Lanka, which is renamed SriLankan. Emirates is voted Best Airline in the World at prestigious OAG Awards. he $540 million Terminal 2 is opened at Dubai International. 1997 Emirates makes a $2 billion order for 16 Airbus A330-200s. Airline defies high fuel prices to again post record profits as passenger figures top three million and the cargo haul hits 150,000 tonnes. Emirates takes delivery of six Boeing 777-200s, giving it new long-haul capabilities. 1996 Airline takes delivery of its first Boeing 777-200 and becomes the first airline to show live footage of take-off and landing. Its maiden flight to London is followed by Emirates’ inaugural flight to Melbourne. Emirates becomes title sponsor of the world’s richest horse racing event – the Dubai World Cup. 1995 As the airline celebrates its 10th birthday, it has a fleet flying to 34 locations in the Middle East, Far East and Europe. Emirates enters the African market, with flights into Johannesburg, Nairobi and Kenya. Sheikh Ahmed’s aim for more Emiratis to forge careers with Emirates starts to take shape as the first pilots graduate from Emirates’ training programme. Emirates Flight Training Centre opens. 994 Emirates is the first airline to equip an Airbus fleet with an on-flight fax facility. 1993 Emirates becomes the first airline to introduce telecommunications on an Airbus – in all three classes. 1992 Emirates becomes the first airline to install video systems in all seats in all classes throughout its fleet. Emirates convinces the French government to allow it to fly into Paris. $2 million terminal exclusive to Emirates is opened at Dubai International. Emirates becomes first airline to order a $20 million Airbus full-flight simulator. 1991 On January 17, Emirates grounds its fleet for several hours as the battle to liberate Kuwait begins. Operations resume and Emirates’ maintains 90 per cent of its normal services during the first month of the conflict. Emirates finally gets a slot at the busiest international hub in the world – London Heathrow. Shortly after the arrival of another Airbus A300-600R, taking its fleet to nine, Emirates orders seven Boeing 777s, with an option for seven more, in a $64. 5 million deal. As the airline celebrates its sixth anniversary, 25,000 passengers a week are being flown to 23 destinations. 1990 Sheikh Ahmed signs up for three more Airbus A310-300s at the Asean Aerospace exhibition in Singapore. Emirates bucks the industry trend and continues to expand despite the Iraqi invasion of Kuwait and adds Manchester to its schedule. Flights are added to Singapore, Manila and Bangkok. 1988 Damascus is added to the Emirates route network, giving it a total 12 destinations in just 38 months of business. Deals are struck to fly into London’s Gatwick Airport, as well as Istanbul, Frankfurt and Male, the capital of the Maldives. On July 3, A6-EKA flies from to Toulouse to Dubai as Emirates takes delivery of its first bought aircraft. The Airbus A310-304 is designed to Emirates specifications, giving the airline the opportunity to fully implement its commitment to offering a superior flying experience than its rivals. 1986 The network grows with traffic rights acquired into Amman, Colombo, Cairo and Dhaka. Investment in infrastructure and expansion costs sees Emirates posting losses for what would be the only time in its history. 1985 Sheikh Mohammed introduces Mr. Flanagan to his uncle and future Emirates chairman Sheikh Ahmed bin Saeed Al Maktoum. Mr. Flanagan embarks on ambitious mission to launch an airline with $10 million in five months. Sheikh Ahmed and future president Tim Clark join Mr. Flanagan’s team. Pakistan International Airlines agrees to wet-lease Emirates two aircraft. Deals are struck to fly into Karachi, New Delhi and Bombay. A PR disaster is thwarted by recruiting 80 Emirates staff to travel incognito to disguise the dismal sales of tickets on the maiden flight. On October 25 Flight EK600 departs Dubai International for Karachi. Sheikh Mohammed gifts two Boeing 727-200s to the airline. 1984 Sheikh Mohammed bin Rashid Al Maktoum and Mr. Flanagan discuss launching an airline in Dubai. Mr. Flanagan is among a 10-man team which produces a business plan for the new airline – to be named either Dubai Airlines or Emirates airline. Sheikh Mohammed opts for Emirates and the decision is made to build the airline on top of dnata, which was already the sales agent for 25 airlines. 1978 Maurice Flanagan moves to Dubai to become director and general manager of dnata. 1960 Sheikh Rashid bin Saeed Al Maktoum opens the airport and implements innovative open-skies policy. 1959 Dnata is established by the Dubai Government with just five staff to provide ground handling services at the new Dubai International Airport. How to cite History of Emirates Airlines, Papers