Determination of Vitamin C Content in Foods

Determination of Vitamin C Content in Foods Zheng Xiao Introduction Vitamin C, also known as L-ascorbic acid, is an essential component of our diets. It is a good antioxidant, a key component that helps to prevent damage to proteins and deoxyribonucleic acids. In the food industry, vitamin C is added to increase the nutritional content of food products and also for preservative purposes. As the human body is unable to synthesise vitamin C, it would have to be consumed as part of our diet. Fresh fruits and vegetables for instance are common sources of vitamin C. Vitamin C is a labile compound and is easily degraded by enzymes and atmospheric oxygen. Its oxidation can be accelerated by excessive heat, light, and heavy metal cations (Pisoschi, Danet, Kalinowski, 2008). During the manufacturing process, some vitamin C would be lost. Thus, in fruit juice products, vitamin C level is commonly used as a gauge for quality. This prompts manufacturers to fortify their products with high levels of vitamin C to ensure that sufficient vitamin C is present in the product throughout the storage process. Due to the wide use of ascorbic acid in both food products and in the pharmaceutical industry, many analytical methods exist for the determination of ascorbic acid, including titrimetric, spectrophotometric and chromatographic methods, each with their advantages and disadvantages. An example of a titrant used is 2,6-dichlorophenolindophenol (DCIP), which will oxidise the ascorbic acid that is present in the sample. While titrimetric methods are simple to use, they are also known to overestimate the amount of ascorbic acid present due to the presence of oxidisable species other than ascorbic acid (Hernà ¡ndez, Lobo, Gonzà ¡lez, 2006). In addition, many interferences often occur with coloured samples (Arya, Mahajan, Jain, 2000). An example would be the masking of colour change at the end point of titration by highly coloured extracts from fruits and vegetables (Eitenmiller, Landen, Ye, 2007). Spectrophotometric methods work by determining the absorbance of vitamin C which is compared against standard concentrations. However, such methods are susceptible to possible interference due to absorbance exhibited by other components that is present in the sample matrix. Lastly, chromatographic methods are commonly used because of their simplicity, short analysis time and sensitivity (de Quirà ³s, Fernà ¡ndez-Arias, Là ³pez-Hernà ¡ndez, 2009). The sample is separated into its components based on their relative affinity with the mobile and stationary phase. Reversed-phase high performance liquid chromatography (RP-HPLC) for instance is a very efficient method that is used in ascorbic acid analysis of fruits, vegetables and beverages. Ascorbic acid is relatively hydrophilic due to the presence of several hydroxyl groups. Thus, it has a higher affinity to the polar mobile phase than the non-polar stationary phase, allowing it to be separated from the other components in a sample. The retention time gives a qualitative analysis of the sample while the area under the peak allows for the quantitative determination of ascorbic acid content present. However, a major disadvantage of this method is its high cost compared to other conventional methods. The objective of this experiment is to determine the ascorbic acid content in commercial guava juice by RP-HPLC. Materials and Methods The product analysed was commercial guava juice. The experimental procedure was as stated in the laboratory manual, with the slight amendments as follows. The filtrate (2mL) from the centrifuged sample was diluted (1 part sample: 4 part acetic acid) with 2% acetic acid. Five sets of standard ascorbic acid solutions were prepared (40ppm, 80ppm, 120ppm, 160ppm and 200ppm for each set) using a stock solution (1000ppm ascorbic acid) and 2% acetic acid for dilution. The standard solutions were filtered using the 0.45 micron cellulose acetate syringe filter, beginning with the lowest concentration. The column used was a Phenomenex Ultrasphere 5u C18 column (1504.6mm) and the wavelength used was 254nm. Results and Discussion A calibration graph was plotted (Figure 1) using average peak area (Table A1 in appendix) for standard solutions versus their respective concentrations. For each standard solution, four duplicates were prepared. This was done to increase the accuracy of the calibration curve. The r2 value obtained (0.9984) was close to the ideal value 1, indicating a good linear correlation between the area under peak of interest and ascorbic acid concentration. This allows good estimates of ascorbic acid content to be made given the area under peak of interest for each sample. Table 1. Ascorbic acid concentration in samples prepared by Groups 10 to 18 Sample calculation for Group 11: Ascorbic acid concentration in diluted sample = = 116ppm Ascorbic acid concentration in original sample = 116ppm 5 = 581ppm = 58.1 mg / 100mL of juice Average ascorbic acid concentration in original sample = =58.0 mg / 100mL of juice The average retention time of the samples prepared by different groups was 2.557min (Table A3 in Appendix), which is highly similar to that of the ascorbic acid standard solutions was 2.559min (Table A2 in Appendix). This verifies that ascorbic acid was the component analysed. The average ascorbic acid concentration in the guava juice product determined experimentally was 58.0mg/100mL of juice. This was approximately 3.9 times higher than the amount indicated on the packaging (15mg/100mL). As mentioned earlier, As the expiration date is approached, ascorbic acid would be lost to different extents depending on the storage conditions (Kabasakalis, Siopidou, Moshatou, 2000). Manufacturers are known to add ascorbic acid to their products to improve their nutritional value and also to account for the ascorbic acid lost during the manufacturing and storage process (Ottaway, 2008). Since the experiment was conducted before the expiration date of the product (March 14, 2014), a higher ascorbic acid content would be expected. The original ascorbic acid concentration for group 14 was excluded from the calculation as it was almost double of other results and thus likely to be an outlier. A possible reason might be an error in dilution during the preparation of the sample. The other results were found to be precise with a low standard deviation (1.4) and a low coefficient of variation (2.5%). Conclusion The ascorbic acid content of commercial guava juice determined using RP-HPLC was 58.0mg/100mL of juice. References Arya, S. P., Mahajan, M., Jain, P. (2000). Non-spectrophotometric methods for the determination of Vitamin C. Analytica Chimica Acta, 417(1), 1-14. doi: http://dx.doi.org/10.1016/S0003-2670(00)00909-0 de Quirà ³s, A. R.-B., Fernà ¡ndez-Arias, M., Là ³pez-Hernà ¡ndez, J. (2009). A screening method for the determination of ascorbic acid in fruit juices and soft drinks. Food Chemistry, 116(2), 509-512. doi: http://dx.doi.org/10.1016/j.foodchem.2009.03.013 Eitenmiller, R. R., Landen, W. O., Ye, L. (2007). Vitamin Analysis for the Health and Food Sciences, Second Edition: Taylor Francis. Hernà ¡ndez, Y., Lobo, M. G., Gonzà ¡lez, M. (2006). Determination of vitamin C in tropical fruits: A comparative evaluation of methods. Food Chemistry, 96(4), 654-664. doi: http://dx.doi.org/10.1016/j.foodchem.2005.04.012 Kabasakalis, V., Siopidou, D., Moshatou, E. (2000). Ascorbic acid content of commercial fruit juices and its rate of loss upon storage. Food Chemistry, 70(3), 325-328. doi: http://dx.doi.org/10.1016/S0308-8146(00)00093-5 Ottaway, P. B. (2008). Food Fortification and Supplementation: Technological, Safety and Regulatory Aspects: Elsevier Science. Pisoschi, A. M., Danet, A. F., Kalinowski, S. (2008). Ascorbic Acid Determination in Commercial Fruit Juice Samples by Cyclic Voltammetry. Journal of Automated Methods and Management in Chemistry, 2008. doi: 10.1155/2008/937651 Appendix Table A1. Area under peak of interest for standard solutions Average area under peak for 40ppm = = 2197282 Table A2. Retention Times for standard solutions Table A3. Retention Times for samples prepared by Groups 10 to 18

A braid of loneliness Essay -- Character Analysis, Rayona, Ida

â€Å"The most terrible poverty is loneliness, and the feeling of being unloved.† –Mother Teresa A Yellow Raft in Blue Water by Michael Dorris is a novel about Native American, narrated by three generations of Indian women; Ida the grandmother, Christine the mother, and Rayona. The stories of three people, â€Å"twisting and tying and blending,† fabricate the braid of their relationship. Each of three strands is a complicated composition of hairlines. There is a hairline that all strands have in common and shape this braid: loneliness. Through the story, loneliness played a crucial part in every character’s life. It is the important cause of characters’ action. It shapes the relationship between mother and daughter. Ultimately, one’s loneliness shapes not only that character, but also affects and causes the loneliness in the next generation. The first character who tells her story is Rayona. Being the last generation, she is in the bottom of the well of loneliness. After her parents separated, Rayona lives with Christine, her mother, who habitually changes her job and moves to the new place. Consequently, she never stays in any schools long enough to make some friends. Her life with Christine is also bitter. In Rayona’s opinion, Christine does not take care of her much. She said â€Å"I try to recall what Mom says when she’s sentimental and lonesome: how he was the best one, the only one, because he left her me. How I’m her sterling silver lining, the one who’ll never leave her like he did. Like she did me.† (64) She is disappointed by Christine’s care that exists only in her speech. Lacking of both friends and warm family, Rayona suffered from loneliness. When she goes back to the reservation with Christine to stay with Aunt Ida, Chris... ... ease her with the warmth of my body, to support her with the strength of my arms. But she did not expect this from me, and I did not give it.† The loneliness of mother is the unwanted gift. From generation to generation, the hairlines of loneliness twist and tie the braid of this family. It obstructs the hairline of love. It obstructs the hairline of care. It leads the braid of this family to nowhere. Loneliness is a cell that imprisons mother’s love from reaching the daughter, leaves them feeling unloved, and became lonely. This baneful hairline will continuously distort the braid until they realize. Until they realize that the solution is turning back to face the reality, holding hands and let the truth comes out, then, the three-generation-long loneliness will disappear. The braid will be set in the right shape and tie the family members together with love. A braid of loneliness Essay -- Character Analysis, Rayona, Ida â€Å"The most terrible poverty is loneliness, and the feeling of being unloved.† –Mother Teresa A Yellow Raft in Blue Water by Michael Dorris is a novel about Native American, narrated by three generations of Indian women; Ida the grandmother, Christine the mother, and Rayona. The stories of three people, â€Å"twisting and tying and blending,† fabricate the braid of their relationship. Each of three strands is a complicated composition of hairlines. There is a hairline that all strands have in common and shape this braid: loneliness. Through the story, loneliness played a crucial part in every character’s life. It is the important cause of characters’ action. It shapes the relationship between mother and daughter. Ultimately, one’s loneliness shapes not only that character, but also affects and causes the loneliness in the next generation. The first character who tells her story is Rayona. Being the last generation, she is in the bottom of the well of loneliness. After her parents separated, Rayona lives with Christine, her mother, who habitually changes her job and moves to the new place. Consequently, she never stays in any schools long enough to make some friends. Her life with Christine is also bitter. In Rayona’s opinion, Christine does not take care of her much. She said â€Å"I try to recall what Mom says when she’s sentimental and lonesome: how he was the best one, the only one, because he left her me. How I’m her sterling silver lining, the one who’ll never leave her like he did. Like she did me.† (64) She is disappointed by Christine’s care that exists only in her speech. Lacking of both friends and warm family, Rayona suffered from loneliness. When she goes back to the reservation with Christine to stay with Aunt Ida, Chris... ... ease her with the warmth of my body, to support her with the strength of my arms. But she did not expect this from me, and I did not give it.† The loneliness of mother is the unwanted gift. From generation to generation, the hairlines of loneliness twist and tie the braid of this family. It obstructs the hairline of love. It obstructs the hairline of care. It leads the braid of this family to nowhere. Loneliness is a cell that imprisons mother’s love from reaching the daughter, leaves them feeling unloved, and became lonely. This baneful hairline will continuously distort the braid until they realize. Until they realize that the solution is turning back to face the reality, holding hands and let the truth comes out, then, the three-generation-long loneliness will disappear. The braid will be set in the right shape and tie the family members together with love.

Development And Evaluation Of A Dispersive Liquid Environmental Sciences Essay

It has been developed a small-scale, simple, and rapid diffusing liquid-liquid microextraction ( DLLME ) process in combination with fiber optic-linear array sensing spectrophotometry ( FO-LADS ) with charge-coupled device ( CCD ) sensor profiting from a micro-cell. The official mention methods ( ASTM D2330 – 02, ISO 7875-1 ) which require boring processs were replaced with modified method, as a consequence, it has achieved a major decrease in sample size, riddance of the usage of expensive glasswork, and a lessening in the measure of trichloromethane used every bit good as much more addition in sensitiveness. Our presented method requires merely one twentieth of sample ( 5.0 milliliter ) , less than one three-hundredth of microextraction dissolver ( chloroform = 138 A µL ) , and much reduced in analytical clip compared with official analytical methods ( less than one minute ) . The standardization curve was additive in the scope of 0.06 A- 10-1 – 0.8 A- 10-1 milligra m La?’1 of Na dodecyl sulphate ( SDS ) with a correlativity coefficient ( R ) of better than 0.99 and the LOD was 0.02 A- 10-1 milligram La?’1. The repeatability of the proposed method ( n=7 ) were found to be 4.5 and 3.6 % for the concentration of 0.03 and 0.07 milligram La?’1, severally. The enrichment factor was found to be 75 for SDS. Keywords: Diffusing liquid-liquid microextraction A · Water analysis A · Methylene blue active substance A · Anionic wetting agent A · Fiber optic-linear array sensing spectrophotometry1. IntroductionA turning public concern over protecting our environment obligate chemists, including analytical chemists, to alter their activities in such a manner that they will be conducted in an environmentally friendly mode. Sampling, and particularly sample readying, often involves coevals of big sums of pollutants. This is why sample readying techniques that use a little sum of organic dissolver, or none at all, have been developed [ 1-4 ] . Anionic wetting agents ( AS ) are widely used in family cleaners, industrial detergents and decorative preparations. The wetting agents expelled to natural H2O reservoirs as municipal and industrial wastes are good known to hold inauspicious effects on aquatic beings ; hence the monitoring of wetting agents in environmental samples is of great importance [ 5, 6 ] . For the measuring of entire surfactant concentration, titration methods have been extensively explored [ 7, 8 ] . Several ion-selective electrodes sensitive to anionic wetting agents have been reported so far [ 9-11 ] . Anionic wetting agents are normally determined by spectrophotometric methods utilizing methylene blue ( MB ) , this standard methods being used to find AS in the surface and tap-water samples ( ASTM D2330 – 02, ISO 7875-1 ) [ 12, 13 ] . The method is based on the formation of blue-coloured trichloromethane extractible ion-pair between the AS and the cationic MB. This requires three consecutive extractions of AS-MB content in 100 milliliter of sample with 15, 10, and 10 milliliter of trichloromethane. The ion-pair is determined by spectrophotometry, mensurating the optical density at 650 nanometer. However, these official methods are non merely long and boring but besides require great measures of sample and trichloromethane which has harmful consequence on chemists and environment. Besides, this method needs batch of research lab glasswork, do these operations highly expensive and uncomfortable for the operator. So it seems necessary to seek for new offers as options for the a foresaid method in order to increase the laboratory productiveness, operator safety, comfort, and to cut down drastically the reagents ingestion and waste production. Koga et Al. proposed a decrease of the size of sample employed for AS finding in H2O, being modified this method to utilize 50 milliliter of H2O and 5 milliliter trichloromethane, holding obtained a six times addition of the research lab productiveness [ 14 ] . An other simplified methods that cut down the measures of reagent by utilizing a certain sort of adsorbent have been proposed [ 15 ] . However, this method besides involves boring processs. Besides other research workers studied primary biodegradation of AS in aerophilic showing trials based on the formation of ion-pair of AS and MB [ 16 ] . By early 2006, Assadi and his research group innovated an attractive, high public presentation and powerful liquid-phase microextraction ( LPME ) method which named their techniques â€Å" Diffusing liquid-liquid microextraction † ( DLLME ) [ 17-19 ] . Beyond the trait of simpleness of operation and celerity, ingestion of microextraction dissolver at the micro-level volume and compatibility with analytical instruments are other profitable characteristics of DLLME as a sample pretreatment method [ 20-25 ] For extremely sensitive, accurate, rapid, and cheap measuring with ingestion of extraction dissolver at micro-level volume, we propose a simplification of the spectrophotometric MB method that can be utile for finding anionic wetting agents in aqueous samples. A consecutive DLLME in combination with fiber optic-linear array sensing spectrophotometry ( FO-LADS ) with charge-coupled device ( CCD ) sensor profiting from a micro-cell was used for this intent.2. Experimental2.1 Reagent and criterions The reagents used in the experiments were of analytical class: MB ( used as a cationic dye ) , sodium dodecyl sulphate ( SDS, employed as a representative anionic wetting agent ) , acetone as disperser dissolvers, trichloromethane as microextraction dissolver, NaOH, HNO3 ( 65 % ) , HCl ( 37 % ) , acetic acid, and Na ethanoate for doing buffer solution ) and obtained from Merck ( Darmstadt, Germany ) . Absolute ethyl alcohol ( & gt ; 99.6 % ) purchased from Bidestan company ( Qazvin, Iran ) . The needed measure of SDS was dissolved in pure H2O to do standard solution of 1000 mg L-1. The stock solutions of MB ( 3 A- 10-3 mol L-1 ) were prepared by fade outing appropriate sums in dual distilled H2O. All the plastic and glasswork were cleaned by soaking for 24 H in 10 % v/v HNO3. After cleansing, all containers were exhaustively rinsed three times with dual distilled H2O and twice with acetone prior to utilize. No any detergent was used to clean glasswork because it is hard to take from surfaces and causes high consequences. 2.2. Apparatus and Instrumentation apparatus The fiber optic-linear array sensing spectrophotometer was perched from Avantes ( Eerbeek, Netherlands ) . The light beam from the UV-Vis beginning ( Deuterium-Halogen ) was focused to the sample micro-cell ( Starna Scientific, Essex, England, Cat. NO. 16.40F-Q-10/Z15 ) . The spectrograph accepts the light beam transmitted through the optical fibre and disperses it via a fixed grate across the 2048 component CCD-linear array sensor. The instrumental parametric quantities are listed in Table 1. A Universal EBA 20 extractor equipped with an angle rotor ( Angle rotor for 8 A- 15 milliliter tubings, 6000 revolutions per minute, Cat. No. 2002 ) were obtained from Hettich ( Kirchlengern, Germany ) . An adjustable pipette ( 10-100 A µL ) was prepared from Brand ( Wertheim, Germany ) . All 0.1, 1.0 and 2.5 milliliter panpipes were prepared from Hamilton ( Reno, NV, USA ) . To clean out the micro-cell, avoid any memory consequence and better the repeatability of process, it was washed three times by about 2 milliliters of propanone between each analysis and dried with a watercourse of cold air by usage of a hair drier. 2.3. Mention process Hundred milliliter of sample was placed into a 250 milliliter dividing funnel and 10 milliliter of a 1 A- 10a?’3 mol L-1 MB solution and 15 milliliters trichloromethane were added. After agitating the mixture smartly for 1 min, the two stages were let to divide and chloroform bed taken for analysis. Each sample was extracted to boot two times utilizing 10 ml part of trichloromethane and optical density measurings were made at 650 nanometers in forepart of an external standardization prepared from SDS. Solutions in the scope between 0.1 and 0.5 milligrams La?’1 were extracted in the same manner than samples. 2.4 Recommended analytical process Into a series of screw cap glass trial tubing with conelike underside 5.0 milliliter of the standard SDS solutions at the concentration in the studied scope were pipetted out. Then 25 A µL of 3 A- 10-3 mol L-1 MB standard solution was added. Afterwards, 2.00 milliliter ethyl alcohol ( disperser dissolver ) incorporating 138 A µL trichloromethane ( microextraction dissolver ) was injected quickly into the sample solution utilizing a 2.50-mL syringe. This injection led to a cloudy solution, caused by the all right droplets of trichloromethane into the aqueous sample. The stage separation was accelerated by centrifugating at 5500 revolutions per minute for 3 min. After this measure the spread all right droplets of trichloromethane were settled at the underside of the aqueous solution in conelike trial tubing. Subsequent to this process, for evacuating the upper aqueous solution a long needle connected to 10-mL injection syringe was immersed down in to prove tubing and pulled the spe culator up till minute 200-300 A µL of aqueous stage remains at the top of organic bed. The volume of the settled organic stage was determined utilizing a 100-i? ­L microsyringe at 25  °C which was 65A ±2 A µL. Sixty micro-liter of this settled stage was removed by micropipette and introduced into micro-cell. The ordinary optical density of AS-MB ion-pair in trichloromethane was measured at the wavelength of 650.0 nanometers by agencies of FO-LADS.3. Result and treatmentIn order to obtain a high sensitiveness, the parametric quantities impacting the DLLME such as the type of the microextraction and the disperser dissolvers every bit good as their volume, concentration of MB, pH, and the microextraction clip were optimized. The enrichment factor ( EF ) was defined as the ratio of the analyte concentration in the settled stage to the initial analyte concentration in the aqueous sample. The analyte concentration in the settled stage was calculated from the standardization graph obtained by the conventional liquid-liquid extraction ( LLE ) /FO-LADS ( extraction conditions: 2.0 milliliters standard H2O sample in the concentration scope of 4.5 A- 10-4 – 1.5 A- 10-3 mol L-1 of MB and 1.5 – 5.0 mg L-1 SDS which extracted with 2.0 milliliters trichloromethane ) . 3.1. Chemical reaction of SDS and MB The equilibrium between SDS, MB and the distribution of SDS-MB ion-pair in H2O and trichloromethane has been qualitatively reported in the literature [ 14 ] . The AS dissolved in H2O are somewhat soluble in trichloromethane. On the other manus, MB dissolves good in both, trichloromethane and H2O, supplying a bluish colour solution in all the instances. When pure H2O is assorted with a chloroform solution of MB, the bluish colour is quickly transferred to the aqueous stage. 3.2. Consequence of ion-pair formation status parametric quantities The overall ion-pair formation status of SDS and MB is concentration of each, pH every bit good as clip needed. Our efforts were chiefly centered on optimising these parametric quantities under our microextraction conditions ( DLLME ) . In this survey the clip required for ion-pair formation were tested between 0 sec -10 min. The consequences, deducing from the ion-pair formation utilizing different reaction times, exhibited that the reaction clip has no any consequence on ion-pair formation efficiency and longer clip period did non better the reaction. In order to find the optimum pH for the ion-pair formation, several sample pH values were varied from 2.5 – 7.5 to prove the ion-pair formation of AS and MB in 5.0 mL H2O samples incorporating 0.04 mg L-1 SDS and extra sum of MB. The highest microextraction efficiency was achieved in the pH of studied scope and we found that in the alkalic solution MB it self would pull out into trichloromethane in absence of any MBAS. In optimisation processs no any buffer solution were used because after adding reagents the pH of solution become somewhat acidity in coveted scope. The influence of the MB concentration on the ion-pair formation/microextraction efficiency was performed in the scope of 0 – 2.1 A- 10-5 mol L-1 while the concentration of SDS was 0.04 mg L-1. During the fluctuation of this concentration the other experimental variables remained changeless. The consequences demonstrated that by increasing the MB concentration up to 1.5 A- 10-5 mol L-1 the microextraction efficiency increased and, so, no fluctuation were observed ( as depicted in Fig. 1 ) . Sing the fact that proposed method is additive up to 0.08 milligrams L-1, hence, the sum of 5 A- 10-5 mol L-1 MB was selected as consider adequate surplus sums. 3.3. Influence of the microextraction dissolver sort and volume The choices of an appropriate microextraction dissolver have a high importance function to acquire a high sensitiveness DLLME, so sort and volume of it were studied and optimized. Microextraction dissolver should hold particular features in DLLME ; it should hold really low solubility in H2O, extraction capableness of interested compounds, and much denseness than H2O. Chloroform and C tetrachloride are available as the most celebrated microextraction dissolvers in DLLME. During our primary surveies we found that C tetrachloride is non capable to pull out the ion-pair of SDS-MB at all. Furthermore, the recommended dissolver in the standard methods is trichloromethane ; hence, it was our extinguished pick. To look into the consequence of microextraction dissolver volume, experiments were performed by utilizing 2.00 mL ethyl alcohol incorporating different volumes of trichloromethane ( 138, 143, 148, 153, 158 and 163 i? ­L ) . By increasing the volume of trichloromethane from 138 to 163 A µL, the volume of the settled stage additions about from 65 to 90 A µL. Harmonizing to consequences ( Fig. 2 ) , optical density lessenings with increasing the volume of trichloromethane ; it is clear that by increasing the volume of trichloromethane the volume of the settled stage additions. Subsequently, at low volume of the microextraction dissolver high optical density or enrichment factor was obtained. 3.4. Influence of the disperser dissolver sort and volume In DLLME, choosing an appropriate disperser dissolver is of import, since disperser dissolver should be mixable with both microextraction dissolver and aqueous sample. For the interest of geting the most suited disperser dissolver, two sorts of instead safe disperser dissolvers: propanone and ethyl alcohol were studied. A series of sample solutions were studied by utilizing 2.00 milliliter of each disperser dissolver incorporating 138 A µL of trichloromethane and the enrichment factors were investigated. The consequences showed that ethyl alcohol showed much better efficiency than propanone ( enrichment factor of 75 and 17, severally ) . Less toxicity and the higher microextraction efficiency of ethyl alcohols make it a better pick. After taking ethanol as disperser dissolver, it is necessary to optimise the volume of it. The influence of the disperser dissolver ( ethanol ) volume on the microextraction efficiency was tested over the scope of 0.50 – 2.00 milliliter, but the fluctuation of the ethyl alcohol volume ( disperser dissolver ) caused alterations in the settled stage volume. Hence, it was impossible to see independently the influence of the ethyl alcohol volume on the microextraction efficiency in DLLME. To avoid this job and in order to achieve a changeless volume of the setteled stage, the ethyl alcohol and trichloromethane volumes were changed at the same time. The experimental conditions were fixed and included the usage of different ethanol volumes: 0.50, 1.00, 1.50, and 2.00 milliliter, incorporating 97, 102, 121, and 138 I?L of trichloromethane, severally. Under these conditions, the settled stage volume remained changeless ( 65 A ± 2 I?L ) . Fig. 3 shows the curves for optical density o f SDS-MB ion-pair versus the volume of ethyl alcohol. The optical density increased, when the ethanol volume increased from 0.50 to 2.00 milliliter of ethyl alcohol as disperser dissolver. Harmonizing to the consequences, a 2.00 milliliter ethyl alcohol was chosen as the optimal disperser dissolver volume. 3.5. Influence of the microextraction clip Microextraction clip ( interval clip between the injection of a mixture of disperser dissolver and microextraction dissolver, before get downing to centrifugate ) is of import factor that may be effects microextraction efficiency of analytes from aqueous stage to organic stage. The fluctuation for microextraction efficiency of SDS-MB as a map of microextraction clip was studied in the scope of 5 unsweet – 10 min. The ensuing informations, exposing that the microextraction clip has no important consequence on the microextraction efficiency for the mark compound. It was revealed that after the formation of the cloudy solution, the contact country between the microextraction dissolver and the aqueous stage was well big, defining why the extraction equilibrium could be established really fast. In this method the most time-consuming process was centrifugation of the sample solution in the microextraction process, which was about 3 min. Sing the fact this period of clip ( 3 min ) is for eight trial tubing ( microextraction vass ) , the clip required for managing one trial tubing is less than 25 seconds. 3.6. Analytic features of the method To measure the practical pertinence of the proposed DLLME/FO-LADS technique for finding of MBAS in H2O samples, several analytical public presentation features such as enrichment factor, one-dimensionality, bound of sensing ( LOD ) and repeatability were investigated under optimized conditions. The standardization curve was additive in the scope of 0.06 A- 10-1 – 0.8 A- 10-1 milligram La?’1 of SDS with a correlativity coefficient ( R ) of better than 0.99. The LOD, defined as CL =3 SB/m ( where CL, SB and m are the bound of sensing, standard divergence of the space and incline of the standardization graph, severally ) , was 0.02 A- 10-1 milligram La?’1. The repeatability of the proposed method expressed as comparative criterion divergences ( RSDs, n=7 ) were found to be 4.5 and 3.6 % for the concentration of 0.03 and 0.07 milligram La?’1, severally. The enrichment factor was found to be 75 for SDS. 3.7. Consequence of diverse ions and application to practical samples Any organic or inorganic compound that will organize a trichloromethane extractable ion-pair with MB will interfere by bring forthing high consequences. These positive intervention include organic sulfonates, carboxylates, phosphates, and phenols, every bit good as inorganic cyanates, chlorides, nitrates, and thiocyanates. On the other manus, any compound efficaciously viing with MB to organize an AS ion-pair will give negative consequences. These negative interventions cause by some aminoalkanes and have analytical significance in the instance of quaternate ammonium compounds. For pretreatment of MBAS in all Waterss and waste Waterss that contain meddlesome substances the undermentioned process is recommended by ASTM mention method. The selected sample is hydrolysed by boiling under partial reflux with hydrochloric acid. The residuary merchandises are neutralized to a controlled pH value, and reacted with 1-methylheptylamine. The resulting ion-pairs are extracted into a trichloromet hane stage and evaporated to dryness on a steam bath. The amine constituent of the ion-pair is removed by boiling in an aqueous alkaline media and the stray MBAS are so determined under the described mention process. Besides other research workers examined the consequence of assorted diverse ions on the finding of AS by similar method [ 14, 6 ] . In order to set up the cogency and pertinence of proposed method, it was applied to the finding of AS in several existent H2O samples ( mineral, pat, and good H2O samples ) by proposed method. For this intent, 5.0 milliliter of each sample was preconcentrated utilizing DLLME technique as described before ( pH was adjusted with acetic acid/sodium ethanoate buffer if necessary ) . In order to measure matrix consequence, the standard add-on method was applied for the finding of AS ( at spiking degrees of 0.02 and 0.05 mg L-1 ) in spiked existent samples which the comparative recoveries of analytes are mentioned in Table 2. The obtained consequences were compared with those obtained from spiked distilled H2O. In all instances, the spike recoveries confirm the dependability of the proposed method. The obtained comparative recoveries indicates that matrix does non act upon the microextraction efficiency in the mentioned samples ( no serious interventions ) , hence, there was non any duty t o take interventions. As it can be seen in table 3, the public presentation of proposed method shows distinguishable advantages over other methods with mention to try volume, extraction dissolver volume, RSDs, LODs and additive dynamic scopeDecisionsThis survey demonstrated that DLLME process with really pleasant and robust features for check of AS seems to offer possible campaigners for mention method, which utilizes really little sum of microextraction dissolver every bit good as its low cost. Furthermore, freshly DLLME process in combination with FO-LADS equipped with charge-coupled device ( CCD ) sensor profiting from a micro-cell demonstrated that LPME ( DLLME ) could be combine with spectrophotometer system despite of micro-level sample volume without any dilution and diminishing the sensitiveness. Analysis of several existent samples for AS content illustrated the truth, dependability, simpleness, dependability and bargain rate of method. It appears to be a time-saving techni que, chiefly for research labs executing analysis of a big figure of samples with a rapid coverage clip. Besides we suggest the pertinence of this method for supervising the biodegradation of AS.

Adeline Yen Mah Essay Example

Adeline Yen Mah Essay Example Adeline Yen Mah Paper Adeline Yen Mah Paper Some readers might say Adeline had presented a picture of childhood which was consistently unhappy? Do you agree? Chinese Cinderella is about a young girl battling through life and many misfortunes to finally get a good future, which she gets through sheer perseverance. I believe that Adeline Yen Mah does have a terrible childhood which consists of mainly sorrowful situations; but her being an optimistic child; she is able to transform little actions into something she can find pleasure from. Therefore in this essay I will discuss how I disagree with the statement Some readers might say Adeline had presented a picture of childhood which was consistently unhappy, as I believe that however rarely it took place there were a few happy situations. I will also try to discuss the idea of how each of these happy situations are transformed each time into depressing situations. The story begins with an enthusiastic child, overjoyed by the recent events where she was awarded a prize at school. She is then delighted about the fact that her dearly loved Aunt Baba would keep her certificate in the same box in which she kept her truly, valuable, possessions, as if her award were also some precious jewel impossible to replace. Therefore I believe she did have moments of true happiness but they were short-lived as these emotions are soon distorted by the adversity she received through her family. For example we are then informed of the sad matter of how no one goes and visits her at school when she receives theses prizes. In this same scene we find out how Adelines own sister blamed her, a four year old child, for the death of their mother. If you had not been born Mama would still be alive. I feel that this show the true extent of how horrible her family were to her and how lonely she may have felt throughout life. Soon after, because of the Japanese invasion, Adeline moves with her family to Shanghai, where she is enrolled into another school. She was excited yet nervous. But again her emotions are quickly transformed into the feeling of resent as she realises that no one had made plans on how she was to travel to and from school. After getting lost she phones home and realises no one had missed her. This again shows how her happiness is always short-lived. Rules basically form our lives. The rules that Adeline has to live with are truly unpleasant and her life is very restricted. She is not given any pocket money, tram fare, or new clothes. This shows her life in general was not a chain of happy events and did consist of misery. An important event to consider was when we are told that the children had been looking forward to Chinese new year for weeks and their new outfits. Again, this however small it may be his is obviously something that Adeline found pleasure in, or it would have been if she didnt get a basic, brown smock mode of material left over from one of big sisters garments. This shows she is not considered nearly as important as Niangs biological children, who get beautiful new clothes in all occasions. All throughout the story it is very clear to see there is a very apparent division between Niangs children and Adelines brothers and sister. Niang and her biological children live on the first floor, unlike Adeline and brothers and sisters who are to live on the second floor. Adeline and the others are not allowed to step foot on the first floor yet Niang can enter their rooms at any time to inspect it. This is Niangs way of showing authority in the family as they now live under her roof, and therefore her rules. Even though Adeline and her siblings were treated poorly by their parents, in chapter 9 her and her siblings unite together to organise themselves against Niang, even though the plan does not go ahead, the actuality that she is finally part of a family or a group obviously means a lot to her, yet this diminutive bit of happiness which she holds onto is taken by her own brothers who play a revolting prank on her where they trick her into drinking their urine. This scene tells us that, all that Adeline really wants is to be accepted, she wants to be part of something, and not have to be alone. I hope I have been able to show you clearly how it is that Adeline does have moments of happiness however small they may be but the point I am trying to make is that they are short lived and soon turn into a miserable situations. Each happy memory so far clearly turns into a heartbreaking, demoralizing situation. Another memory which is hastily transformed into a depressing remembrance is when Adeline was given a pet duckling known better as P. L. T.

Staff Training And Development Essay The WritePass Journal

Staff Training And Development Essay Introduction Staff Training And Development Essay CIPD in EWCO (2009). ‘Impact of recession on workplace training’. Available from: eurofound.europa.eu/ewco/2009/09/UK0909039I.htm. Last Accessed on 13th Dec. 2012 3.Deal, T.E., Kennedy, A.A., (1982) :Corporate Cultures: The Rites and Rituals of Corporate Life, Harmondsworth, Penguin Books 4.Garrison, D.R., Anderson, T., (2003) :E-Learning in the 21st Century, RoutledgeFalmer, Taylor Francis Group Hall, D. T., Moss, J. E. (1998). ‘The new protean career contract: Helping organizations and employees adapt’.Organizational Dynamics, 26, 22–37. Herzberg, F. (1966) :Work and the Nature of Man, Staples Press Holbeche, L. (2006), Understanding Change: Theory, Implementation and Success, Elsevier Butterworth-Heinemann Hung, H. Wong Y. (2007), The relationship between employer endorsement of continuing education and training and work and study performance’: A Hong Kong case study. International Journal of Training Development, 11, 4, pp. 295-313. Irving, P. G., and Meyer, J. P. (1999). ‘On Using Residual Difference Scores in the Measurement of Congruence: The Case of Met Expectation Research. A Longitudinal Analysis’, Personnel Psychology, 52(1), pp. 85-95. Jerling K. (1996). Education, Training, and Development in Organisation. Pearson: South Africa Keeney, M. J., Svyantek, D. J. (2000). ‘A review of psychological contract theory and research: Promise nothing and they still may get angry’. Current Trends in Management, 5, 65–94. Kimberly, W. 2009, Value Initiatives Improving Performance in the Workplace. NY:GRIN Verlag 9.Lamb, R., (1984) Competitive Strategic Management, Prentice Hall 10.Lambin, J.J., (2000) Market-Driven Management: Strategic Operational Marketing, MacMillan Business Landale A. (1999). Gower handbook of training and development. 3rd ed., Gower Publishing: UK 11.Maslow, A.H. (1943), ‘A theory of human motivation’, Psychological Review, Vol. 50 No. 4, pp. 370 396. 12.McConnell, C. R. 2004, Managing Employee Performance, Health Care Manager, Vol. 23, No. 3, p. 273, Supplemental Index. 13.Pedler, M., Burgoyne, J., Boydell, T., (2003) A Manager’s Guide to Leadership, McGraw-Hill Phillips, J.J., Pulliam Phillips, P., (2002) Retaining Your Best Employees: In Action Case Study Series, American Society for Training and Development Rabey, G., (2003) The Paradox of Teamwork, Industrial and Commercial Training, Vol. 35, No. 4, pp. 158 – 162 Robinson, S. L. (1996). ‘Trust and breach of the psychological contract’. Administrative Science Quarterly, 41:574–599. Robinson, S. L., Morrison, E.W. (1995a). ‘Psychological contracts and OCB: The effect of unfulfilled obligations on civic virtue behavior’. Journal of Organizational Behavior, 16: 289–298 Roughton, J. Mercurio, J. 2002, Developing an effective safety culture: A Leadership Approach. NY: Butterworth-Heinemann 17.Schein, E.H. (2004): Organizational Culture and Leadership, Jossey-Bass 18.Thompson, J.L., Martin, F., (2005) Strategic Management: Awareness and Change, 5th Edition, Thomson Learning 19.Smith, M. K., (2001) ‘Peter Senge and the learning organisation’, the encyclopaedia of informal education, available online at www.infed.org/thinkers/senge.htm Turnley, W. H., Feldman, D. C. (1999a). ‘The impact of psychological contract violations on exit, voice, loyalty, and neglect’. Human Relations, 52, 895–922. Van den Bossche, P., Segers, M., Jansen, N., (2010) Transfer of Training: The Role of Feedback in Supportive Social Networks, International Journal of Training and Development, Vol. 14, Iss. 2, pp. 81 – 94 van Dam, N. (2002). E-learning by design: Can a better-designed course help you learn more? e-learning. 3(1), 38-39. Venkatesh, V. and Goyal, S.(2010). ‘Expectation Disconfirmation and Technology Adoption: Polynomial Modeling and Response Surface Analysis,’MIS Quarterly 34, (2), 281-303 Vroom, V.H. (1964), Work and Motivation, John Wiley

Consumerism and Identity Essay Example | Topics and Well Written Essays - 1000 words - 10

Consumerism and Identity - Essay Example In this paper I will qualify the statement that the capitalist commercial culture has been blamed for the bad experiences in the society. Argument for the Claim The society has continually faced problems that range from economic to political, and fingers point to the commercial culture of capitalism. Profit motive in the commercial sector plays an important role on food that people eat and to a great extent account for effects of other consumables. Emergence of economic concepts of cost minimization towards optimal profits play a core role as capitalists seeks less costly strategies to productions and marketing strategies for market control. In the food industry, for example, industrialization has transformed eating habits to commercially processed foods that are rich in chemicals and fats and expose consumers to eating disorders such as overweight. Using the media to penetrate into new markets also influences consumers towards the capitalists’ products and increases incidence s of effects of industrial products (Twitchell 1). Economic effects of capitalism also support the claim that the commercial culture is responsible for depression and associated disorders among members of the society. Unlike in socialist culture where the society owns resources and collectivism ensures needs of every member of the society, capitalism concentrates excessive resources on a few individuals while a majority of members of the society remain in poverty and have to struggle for their needs. Human suffering due to lack of basic needs or wants therefore flourish in the society while a non-capitalist system would have resolved such conditions. The condition worsens by capitalists’ selfish interest that seeks to increase the capitalists’ possession at the expense of the working class that mainly lives in poverty. Capitalist commercial culture has also threatened social cultures and cultural figures through undermining cultural values. Competitiveness in the corpo rate sector and the profit orientation of capitalists has for example promoted creativity into cultural shifts in what appears as better practices and utilities. Cultures and their benefits to the society have suffered from the developments as they become inferior and lose value. High level of competition in the market and self-interest has also promoted ills such as corruption and associated consequences in substandard products that risk consumers’ lives and undermine economic growth (Twitchell 1). Established criticisms of the commercial culture also support Twitchell’s position that the culture does not benefit the society. Some oppressive conditions are manageable, especially through collective responsibility as observed in socialist culture, but self-centered interest in the capitalist culture overlooks strategies for resolving the conditions. Widening gap between economic classes is an example and explains why the poor get poorer and the rich continue to amass we alth. Capitalistic culture also undermines efforts for harmonizing living standards in the economy and promotes such acts as discrimination and exploitation to promote suffering and stress.

Social Media and Employment Research Paper Example | Topics and Well Written Essays - 2250 words

Social Media and Employment - Research Paper Example Instead of using social networks as a mere communication channel, people started to exploit it in different ways. For example, employers are using social networks nowadays, to identify potential candidates for the vacancies in their organizations. Recruitment through social networks is the cheapest and quickest way of filling vacancies in an organization. This paper analyses various ways through which social networks can be used for the recruitment process and also the advantages and disadvantages in using social networks for the recruitment process. Definition: Social Networking â€Å"Social networking is the grouping of individuals into specific groups, like small rural communities or a neighborhood subdivision. When it comes to online social networking, websites are commonly used. These websites are known as social sites†(What is social networking, 2011). Social sites help to build an online community in the virtual world to function like a social community in the real worl d. Online community can accommodate people from distant parts of the world irrespective of their cast, age, race, gender or religion. Background: Social Networking & Employment Just like alcohol or drug addiction, social media or social networking is a kind of addiction to most of the people in the current generation. Majority of the people who know something about computers and internet may have accounts in social media networks to communicate with their friends and relatives and also to express their views to the external world. The capabilities or potentials of social media networks are increasing day by day. Earlier, people used it for sharing photos, videos, music and opinions; however at present social media networks have been used for many other purposes. For example, leaders of the ongoing struggle against corruption in India have used social media networks such as Twitter and Facebook extensively to gather support for their agitations against corruption. Identification of t alents or recruitment process is another area in which social networks started to show its potentials. Since people reveal their qualifications and experiences in their profile, it is easy for the employers to search through databases of social networks and identify the talents they are looking for. Since social networks provide a platform for people to express themselves or to express their views, employers can easily identify whether a person is suitable or not for their organization. Even though social networks provide immense advantages both to the employers and the job seekers, employers may face lot of disadvantages also while using social networks for recruitment purposes. It is not necessary that people always provide details about their actual qualifications and experiences in their profile in social networks. In many cases, people provide exaggerated claims about their qualifications and experiences in their social network profiles in order to attract others and the employ ers may not get the actual information about a person while using social networks for recruitment process. Some of the social websites like LinkedIn provides not only the facility to put the user’s resume online, but also it helps the employers the facilities to communicate effectively with the job seekers. Employers can use these facilities effectively to identify talents. According to Lindow (2011), â€Å"LinkedIn can be a good place to start, because what LinkedIn has done is given people the permission to put their resume online,†