chemical methods of sample preparation

... ABBREVIATIONS LIST OF PUBLICATIONS IV VI SUMMARY VII CHAPTER 1 GENERAL INTRODUCTION 1.1 GENERAL REMARKS ABOUT SAMPLE PREPARATION METHODS 1.2 OVERVIEW OF SAMPLE PREPARATION METHODS 1.2.1 MICROWAVE-ASSISTED ... Following are general information about sample preparation methods A complete sample analysis procedure includes steps: Sample collection, sample preparation, sample analysis, data handling and final ... Therefore, developing new sample preparation and pretreatment methods is urgently needed These needs have driven the development of a wide range of new sample preparation methods, such as microwave...

Ngày tải lên: 16/09/2015, 15:54

... total plant biomass of each sample, were identified Vegetation was harvested on a 0.25 m circular area of each sample plot and bulked within a subplot Dry biomass of each sample was recorded ... combination to compare methods of soil cultivation (whole plots), levels of weed control (subplots), and size classes of planting stock (sub-subplots) For the purpose of this study, the seedling ... consisted of cross classification of subplots between the major species and soil cultivation combined with weed control treatments (samples) In this method, a classification of the samples is...

Ngày tải lên: 08/08/2014, 19:21

... contamination 5.1.2 5.2 Automatic sampler (optional)—The sampler must incorporate glass sample containers for the collection of a minimum of 250 mL of sample Sample containers must be kept refrigerated ... seven days of collection and completely analyzed within 40 days of extraction.2 10 Sample Extraction 10.1 Mark the water meniscus on the side of the sample bottle for later determination of sample ... analysis of a QC check standard will depend upon the number of parameters being simultaneously tested, the complexity of the sample matrix, and the performance of the laboratory If the entire list of...

Ngày tải lên: 14/02/2014, 03:20

... QC check sample to contain 50 µg/L of each parameter by adding 200 µL of QC check sample concentrate to 100 mL of reagent water 8.2.3 Analyze four mL aliquots of the well-mixed QC check sample ... control program The minimum requirements of this program consist of an initial demonstration of laboratory capability and an ongoing analysis of spiked samples to evaluate and document data quality ... addition of 10 µL of this standard to 5.0 mL of sample or calibration standard would be equivalent to 30 µg/L 7.4.3 Analyze each calibration standard according to Section 10, adding 10 µL of internal...

Ngày tải lên: 14/02/2014, 03:20

... 15-40% of Mass 95 30-60% of Mass 95 Base Peak, 100% Relative Abundance 5-9% of Mass 95 50% of Mass 95 5-9% of Mass 174 >95% but 101% of Mass 174 5-9% of Mass 176 Table ... QC check sample to contain 20 µg/L of each parameter by adding 200 µL of QC check sample concentrate to 100 mL of reagent water 8.2.3 Analyze four mL aliquots of the well-mixed QC check sample ... solution of mL of sample or standard is equivalent to a concentration of 30 µg/L of each surrogate standard 6.8 BFB Standard—Prepare a 25 µg/mL solution of BFB in methanol 6.9 Quality control check sample...

Ngày tải lên: 05/03/2014, 21:20

... minimize contamination Automatic sampler (optional)—The sampler must incorporate glass sample containers for the collection of a minimum of 250 mL of sample Sample containers must be kept refrigerated ... prepare QC check samples at a concentration of 100 µg/L by adding 1.0 mL of QC check sample concentrate to each of four 1-L aliquots of reagent water 8.2.3 Analyze the well-mixed QC check samples according ... seven days of collection and completely analyzed within 40 days of extraction.2 10 Sample Extraction 10.1 Mark the water meniscus on the side of sample bottle for later determination of sample volume...

Ngày tải lên: 05/03/2014, 21:20

... minimize contamination Automatic sampler (optional)—The sampler must incorporate glass sample containers for the collection of a minimum of 250 mL of sample Sample containers must be kept refrigerated ... 10 Sample Extraction 10.1 Mark the water meniscus on the side of the sample bottle for later determination of sample volume Pour the entire sample into a 2-L separatory funnel Check the pH of ... Fill the sample bottles and, if residual chlorine is present, add 80 mg of sodium thiosulfate per liter of sample and mix well EPA Methods 330.4 and 330.5 may be used for measurement of residual...

Ngày tải lên: 14/03/2014, 20:20

... minimize contamination Automatic sampler (optional)—The sampler must incorporate glass sample containers for the collection of a minimum of 250 mL of sample Sample containers must be kept refrigerated ... prepare QC check samples at a concentration of 100 µg/L by adding 1.00 mL of QC check sample concentrate to each of four L aliquots of reagent water 8.2.3 Analyze the well-mixed QC check samples according ... seven days of collection and completely analyzed within 40 days of extraction.2 10 Sample Extraction 10.1 Mark the water meniscus on the side of the sample bottle for later determination of sample...

Ngày tải lên: 14/03/2014, 20:20

... incorporate glass sample containers for the collection of a minimum of 250 mL of sample Sample containers must be kept refrigerated at 4°C and protected from light during compositing If the sampler uses ... 8.2.2 Using a pipet, prepare QC check samples at a concentration of 20 µg/L by adding 1.00 mL of QC check sample concentrate to each of four L aliquots of reagent water 8.2.3 8.2.4 Calculate ... later determination of sample volume Pour the entire sample into a L separatory funnel Check the pH of the sample with wide-range pH paper and adjust to within the range of 5-9 with sodium hydroxide...

Ngày tải lên: 22/03/2014, 14:20

... minimize contamination Automatic sampler (optional)—The sampler must incorporate glass sample containers for the collection of a minimum of 250 mL of sample Sample containers must be kept refrigerated ... surrogate compound at a concentration of 100 µg/mL in acetone Addition of 1.00 mL of this solution to 1000 mL of sample is equivalent to a concentration of 100 µg/L of each surrogate standard Store ... prepare QC check samples at a concentration of 100 µg/L by adding 1.00 mL of QC check sample concentrate to each of four L aliquots of reagent water 8.2.3 Analyze the well-mixed QC check samples according...

Ngày tải lên: 28/03/2014, 19:20

... minimize contamination 5.1.2 Automatic sampler (optional)—The sampler must incorporate glass sample containers for the collection of a minimum of 250 mL of sample Sample containers must be kept refrigerated ... check samples at a concentration of 0.100 µg/L (100 ng/L) by adding 1.00 mL of QC check sample concentrate to each of four L aliquots of reagent water 8.2.3 Analyze the well-mixed QC check samples ... the side of the sample bottle for later determination of sample volume Pour the entire sample into a L separatory funnel 10.2 Add 1.00 mL of internal standard spiking solution to the sample in...

Ngày tải lên: 28/03/2014, 20:20

... region of Figure 1, where the CL emission A of the sample studied here is compared with Figure CL spectrum A in the near-IR region of the investigated sample compared with that (B) of a sample ... Page of Table Values of the experimental ratio Rexp of the HAADF intensity IHAADF of sublayer #1 to those of the three alloys (GaAs substrate, In0.51Ga0.49P and Al0.26Ga0.74As) contained in the sample ... ratio Rexp is the one that a sublayer is made of The experimental ratios Rexp of the HAADF intensity of sublayer of the nominal GaAs layer to those of the GaAs substrate, In 0.51 Ga 0.49 P and...

Ngày tải lên: 21/06/2014, 05:20

... Laboratory Samples 9.1 Sample preparation is the reduction of the bulk sample in both particle size and amount of material to the suitable laboratory sample, so as to maintain representation of the ... transfer rates result in large incremental samples The sample must be representative of the entire cross-section flow of material The amount of sample and number of increments must be determined prior ... square root of the variance 3.20 subsample—a sample taken from another sample 3.21 top size—the opening of the smallest screen in the series upon which is retained less than % of the sample 3.22...

Ngày tải lên: 10/07/2014, 23:20

... define the date of branch mortality The stump of the sample tree was seen as the centre of a Bitterlich sample Based on a basal area factor of all neighbouring trees within the relascope sample were ... characteristics of the sample trees Altogether 57 spruces and 43 firs from nine sample plots were measured The sample encompasses trees of different growth histories Mean height of the trees ranges ... Figure the development of height to crown base against height of four sample trees with a different degree of release is shown The individual values of branch mortality of the respective whorls...

Ngày tải lên: 08/08/2014, 01:21

... derivatization of the compounds The enantioselective bioactivity of both acephate and methamidophos in future may produce new method(s) of detection including determination of extent of toxicity of these ... Urinary concentration of acephate was non-detectable after 48 h of the exposure (Maroni et al., 1990) Detection of acephate and methamidophos Based on physicochemical properties of acephate and methamidophos, ... identification and quantification of compounds Ionization of molecules was performed by the electrospray Figure Flow steps of extraction, cleanup and sample loading of organophosphate pesticides...

Ngày tải lên: 02/09/2015, 13:47

... Figure 4-1 SEM of a single graphite fiber xiii Figure 4-2 Influence of heating temperature on MAE efficiency Figure 4-3 Time profile of MAE of PAHs Figure 4-4 Time profile of elution of PAHs Figure ... images of ZHF and PHF: (a) cross-sectional image of ZHF; (b) longitudinal image of ZHF; (c) textural image of ZHF; (d) textural image of PHF; (e) nanopores of ZHF; (f) fibrous structure of PHF ... DEVELOPMENT OF MINIATURIZED SAMPLE PREPARATION APPROACHES by XU LI (M.Sc., WUHAN UNIVERSITY) A THESIS SUBMITTED FOR THE DEGREE OF DOCTOR OF PHILOSOPHY DEPARTMENT OF CHEMISTRY NATIONAL UNIVERSITY OF SINGAPORE...

Ngày tải lên: 14/09/2015, 14:01

... the summer of 2001 where representative samples of DDGS (4.5 kg) were obtained from 16 ethanol plants in Minnesota, South Dakota and Missouri From these samples, a 200 gram subsample of DDGS from ... (lightness of color) and b* (yellowness of color), with an increase in a* (redness of color) Similar results were also reported by Ganesan et al (2005) Table The Effect of the Rate of Solubles ... of Minnesota in 2004 (34 samples from ethanol plants in 11 different states) and 2005 (35 samples) As shown in Tables and 5, average particle ranges 08 - Physical & Chemical Characteristics of...

Ngày tải lên: 08/08/2012, 10:03

... that is, the number of ads, the length of ads and when they are put on the air -Web papers: You probably would not have seen this means of advertising on a list of advertising methods if you had ... categories of services, and the name of your business is descriptive of your services and/or your ad stands out (for example, is bolded, in a large box on the page, etc.) The phone company will offer ... stakeholders with information so make the most of your messages 1.3 The best kind of advertising: The best kind of advertising is probaly what is known as words of mouth advertising, which occurs when...

Ngày tải lên: 15/04/2013, 14:02

... specific sample from an unobservable universe of hedge funds introduces two types of bias, Selection bias and Survivorship bias, characterising main sources of difference between the performance of ... measured in terms of the standard deviation of monthly returns Indeed, during the sample period, the average monthly return of the directional strategies was 0.93% and that of the non-directional ... ratio of 1.05 where the directional strategies exhibit a ratio of 0.75 and in the case of a minimal acceptable rate of 0% non-directional strategies exhibit on average an annualised ratio of 1.75...

Ngày tải lên: 16/04/2013, 20:00

... each kind of sample in order to ensure meaningful results Table 24.3 Preservatives and Preservation Methods Used with Water Samples Preservative or technique used Effect on sample Type of samples ... the first sample? What is the molar concentration of HCl in a water sample containing HCl as the only contaminant and having a pH of 3.80? A 200-mL sample of water required 25.12 mL of 0.0200N ... alkalinity of the original sample? Analysis of a lead-containing sample by graphite-furnace atomic absorption analysis gave a peak of 0.075 absorbance units when 50 microliters of pure sample was...

Ngày tải lên: 23/07/2013, 20:57