bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gas Chromatographic Determination of Lindane (Gamma Isomer of BHC) in Maneb-Lindane Liquid Pesticide Formulations
Authors: Grorud Robert B 
Published: February 2020

Abstract
Lindane from liquid insecticide-fungicide formulations containing lindane with maneb can be determined by gas chromatography using 3% OV-1 or 5% SE-30 columns. Lindane is extracted with acetone, and an aliquot is diluted to volume with anhydrous methanol and injected on-column. The internal standard, diethyl phthalate, has a retention time of 6 min and lindane has a retention time of 12 min, allowing injection every 15 min. Within-laboratory analysis of 3 typical formulations indicates good precision with coefficients of variation ranging from 0.45 to 1.58%. The method can be easily adapted to other liquid or dust formulations of lindane
Determination of Ochratoxin A in Animal Feed and Cereal Grains by Liquid Chromatography with Fluorescence Detection
Authors: Cohen Huguette , Lapointe Michel 
Published: February 2020

Abstract
A liquid chromatographic (LC) method is described for determination of ochratoxin A in animal feeds and cereal grains. Samples are initially extracted with chloroform-ethanol (8 + 2) and 5% acetic acid in water. Extracts are purified using a silica gel cartridge followed by a cyano cartridge. The samples are evaporated, diluted to a known volume, and analyzed using a 10 cm column of 3 μm Cm and a fluorescence detector. The method was applied to a variety of animal feeds and cereal grains at levels of 1.0-0.005 ppm added ochratoxin A. The overall recovery was 90.6% ± 3.6.
Analytical Methods for Measuring Uric Acid in Biological Samples and Food Products
Authors: Pachla Lawrence A , Reynolds Donald L , Wright D Scott , Kissinger Peter T 
Published: February 2020

Abstract
Daring the last 7 decades, uric acid methodology has kept pace with the introduction of state-of-the-art technology (e.g., spectroscopy, electrochemistry, chromatography) or the discovery of unique chemical processes (e.g., redox, enzymatic). We envision this practice will continue in the future. There never will be a single analytical method applicable for biofluids or foodstuffs. Therefore, it is imperative that the analyst not only understand the advantages and disadvantages of a procedure, but also thoroughly understand its underlying chemical and technological principles. Since many procedures available for analysis of biofluids and foodstuffs rely on identical chemical or technological principles, this report shall review both sample types and the available spectroscopic, electroanalytical, and chromatographic methods
Use of Solid Phase Florisil Cartridges to Separate Fat from Semivolatile Organic Compounds in Adipose Tissue
Authors: Chiang Tom C H , Liao Wenta , Williams Llewellyn R 
Published: February 2020

Abstract
A quick method for separation of semivolatile organic compounds from fat in adipose tissue has been developed. This method uses commercially available solid phase cartridges for sample cleanup. The results indicate that the recoveries, from hexane-extracted fat, of 4 representative classes of organic compounds range from 86.2 to 116%. The solid phase cartridges provide excellent separations of the fat from the analytes; no extraneous interference peaks were detected in the gas chromatograms. The method requires only 0.1 g sample and is quick and simple to use. Although results are reported for samples containing 1-14 ppm, the final extract can be concentrated to a volume allowing detection between 10 and 100 ppb.
Determination of Sulfur Dioxide in Foods by Modified Monier-Williams Distillation and Polarographic Detection
Authors: Stonys Dalia B 
Published: February 2020

Abstract
A rapid, sensitive polarographic method is presented for determining sulfiting agents in foods and beverages. The method is based on the modified Monier-Williams distillation followed by polarographic detection by differential pulse polarography or square wave voltammetry. A clearly defined wave is obtained by both techniques, with a current maximum at a potential (E) of about -600 mV vs an Ag/ AgCl reference electrode. The reaction is based on the reduction of sulfur dioxide at a dropping mercury electrode. Peak current was linear over the range 0-20 μg/mL. Quantitation is done by linear regression analysis of standard addition data or by using a standard calibration graph. Screening levels of less than 1 ppm total S02 were easily achieved in the foods analyzed, which had levels from less than 1 ppm (cereals) to thousands of parts per million (dried fruit). Recoveries from fortified samples ranged from 70 to 108% at fortification levels of 20, 100, and 1000 μg/g.
Mass Spectral Investigations on Trichothecene Mycotoxins. II. Detection and Quantitation of Macrocyclic Trichothecenes by Gas Chromatography/Negative Ion Chemical Ionization Mass Spectrometry
Authors: Krishnamurthy Thaiya , Sarver Emory W , Greene Sharon L , Jarvis Bruce B 
Published: February 2020

Abstract
A general, sensitive gas chromatographic/negative ion chemical ionization mass spectrometric (GC/NICIMS) method of analysis was developed for the detection and quantitation of several polar, thermally labile, toxic macrocyclic trichothecenes. The procedure involves the conversion of the molecules to their corresponding alcohols (verrucarols) by alkaline hydrolysis, followed by derivatization of the hydrolysate with heptafluorobutyrylimidazole and analysis by GC/MS technique under negative ion chemical ionization conditions. Nanogram (250 ng) quantities of several macrocyclic trichothecenes with different verrucarol and ester moieties were analyzed successfully with good precision by this procedure. The method was applicable for the accurate determination of at least low ppb levels of these macrocyclic trichothecenes in environmental samples, such as fungal products, fermentation broths, and plant samples. This is the first reported, well developed, sensitive, and applicable method for the detection and quantitation of these compounds in naturally occurring samples.
Quantitative Determination of Total Glucosinolates in Rapeseed and Meal Digests
Authors: Saini Harpal S , Wratten Neil 
Published: February 2020

Abstract
A method has been developed for the quantitative determination of total glucosinolates in enzymic digests of seeds and meals of rapeseed cultivars. The method is based on the determination of the glucose released after myrosinase digestion and subsequent deproteinization, using the glucose oxidase-peroxidase system with 4-aminophenazone as the oxygen acceptor. The myrosinase was prepared from white mustard seeds and partially purified to remove other glucose-liberating enzyme activities. Endogenous enzyme activities in the samples analyzed were also removed by heat treatment before analysis. These conditions allow a rapid and specific estimation of total glucosinolates that is particularly useful in rapeseed breeding programs. The parameters affecting the optimum yield of hydrolytic product (glycose) from the seeds of 2 rapeseed varieties known to contain a high (cv. Target) and a low (cv. Tower) level of glucosinolate contents have been examined. Addition of glucose to the digestion mixtures gave good recoveries (95%) and close agreement between replicates (±5%).
Determination of Residual Chlorinated Solvents in Decaffeinated Coffee by Using Purge and Trap Procedure
Authors: Heikes David L 
Published: February 2020

Abstract
A purge and trap method developed for the analysis of volatile halocarbons (VHCs) in table-ready foods has been applied to the determination of residual chlorinated solvents in decaffeinated coffee. Samples are stirred in water and purged with nitrogen for 0.5 h in a water bath at 100°C. The analytes are collected on a duplex trap composed of Tenax TA and XAD-4 resin, eluted with hexane, and determined by gas chromatography (GC) with a thick-film, widebore capillary column and Hall electrolytic conductivity detector. The higher levels of residual chlorinated solvents are also confirmed by full scan GC/mass spectrometry. Samples are analyzed for several chlorinated solvents including methylene chloride, chloroform, 1,2-dichloroethane, methyl chloroform, carbon tetrachloride, trichloroethylene, and tetrachloroethylene. Eleven decaffeinated instant coffees and 14 decaffeinated ground coffees representing 9 different commercial brands were analyzed by this method. Residues of methylene chloride, chloroform, methyl chloroform, and trichloroethylene were found. Highest levels occurred in ground coffees—up to 640 ppb methylene chloride. Recoveries of these 4 chlorinated solvents detected from fortified samples ranged from 96 to 106%. Brews from 3 instant and 3 ground coffee samples contained up to 1.1 ppb and 4.8 ppb methylene chloride, respectively. In addition, the resulting grounds from the brewing process were analyzed and contained up to 14 ppb methylene chloride and up to 13 ppb trichloroethylene. The limit of quantitation for these coffee grounds was 4 ppb for methylene chloride. Chromatograms from this purge and trap method are clean, enabling levels of about 10 ppb and 0.4 ppb to be achieved for chlorinated solvents in decaffeinated coffees and their brews, respectively.
Gas Chromatographic Method for Determination of Permethrin in Pesticide Formulations: Collaborative Study
Authors: Tyler J F C 
Published: February 2020

Abstract
A gas chromatographic method for determination of permethrin in technical and formulated products has been developed and subjected to a collaborative study involving 19 participating laboratories. Each sample was dissolved in methyl isobutyl ketone containing n-octacosane as internal standard and analyzed by gas chromatography on a glass column with 3% OV-210 on Chromosorb W-HP. Each collaborator was furnished with reference standard and 5 samples of technical material (90-95%), 8 emulsifiable concentrates (10-50%), 2 wettable powders (20-30%), one dustable powder (1-2%), and one mter-dispersible granules (1-2%) for analysis. The coefficients of variation of the results obtained ranged from 0.79 to 4.24%. The method has been adopted as official first action by AOAC.
Amino Acid Analysis for Meat Protein Evaluation
Authors: Ashworth Raymond B 
Published: February 2020

Abstract
The Food Safety and Inspection Service procedure for determination of essential amino acid content of mechanically processed products from red meat animals and poultry is based on hydrolysis of a powder prepared by blending samples in acetone-chloroform. The hydrolysis procedure incorporates thioglycolic acid to prevent loss of tryptophan. Aliquots of prepared hydrolysates are injected into a liquid chromatographic system, using gradient elution on an ionexchange column for separation. The system also uses post-column hypochlorite oxidation coupled with orthophthalaldehyde reagent and fluorescence detection. Modification of the elution program allows concurrent determination of tryptophan with minimal added cost. Chromatograms from beef, pork, and poultry products show adequate separation and quantitation of β-alanine, 1-methyl-histidine, and 3-methyl-histidine, indicating that the procedure could be used to estimate muscle content of products. A colorimetric procedure for assay of hydroxyproline was introduced and validated as an adjunct method for protein quality estimation.
Liquid Chromatographic Determination of Acetaminophen in Tablets: Collaborative Study
Authors: Krieger David J 
Published: February 2020

Abstract
A reverse phase liquid chromatographic method previously reported for the determination of acetaminophen in tablets was collaboratively studied by 5 laboratories. Each collaborator received duplicate samples of a synthetic tablet formulation and 3 powdered commercial tablet composites. The composites represented single-component and multi-component proprietary products and a single-component generic product. The pooled repeatability (CVD„) and reproducibility (CVDJ values for the proprietary tablets were 0.89 and 1.34%, respectively. For the generic tablets, these values were 0.66 and 0.74%, respectively. The pooled recovery value for acetaminophen added to the synthetic formulation was 98.9 ± 0.7% (n = 10) with a CV of 0.75%, CVD„ of 0.37%, and CVD„ of 0.78%. The overall repeatability of the method was 0.64%, and the overall reproducibility was 0.95%. The method has been adopted official first action.
Sulfuric Acid Cleanup and KOH-Ethanol Treatment for Confirmation of Organochlorine Pesticides and Polychlorinated Biphenyls: Application to Wastewater Samples
Authors: HernÁndez Felix HernÁndez , Benet Francisco J.LÓpez , Escriche Julio Medina , Ubeda Juan C.BarberÁ 
Published: February 2020

Abstract
The efficacy of sulfuric acid cleanup and KOH-ethanol hydrolysis confirmation was studied for 22 organochlorine pesticides and 2 polychlorinated biphenyls (PCBs). Mean recoveries for different treatment times are given. The method was applied to analysis of several wastewater samples by gas chromatography with electron capture detection. Organochlorine compounds were extracted by using separatory funnels and 15% diethyl ether in hexane as extractant. All the compounds studied could be analyzed except trifluralin, dichloran, dieldrin, and endrin, which were destroyed after treatment with concentrated H2S04. The pesticides found most commonly in the samples analyzed were fenson, tetradifon, lindane, methoxychlor, and dicofol.
Pesticide Residues in Lake Albufera, Valencia, Spain
Authors: Carrasco Jose M. , Planta Milagros , Gomez-Casals Vicente , Moragues Vicente 
Published: February 2020

Abstract
Analysis of water samples from the lake in Albufera, Valencia, indicates that the pesticides molinate, benthiocarb, and fenitrothion do not reach levels that are lethal to fish.
Microwave Oven Drying Method for Total Solids Determination in Tomatoes:Collaborative Survey
Authors: Wang Samuel L. 
Published: February 2020

Abstract
A survey was conducted among 8 laboratories in Ontario to check the reproducibility and accuracy of their microwave solids analyzers for total solids determination in tomatoes, using the official AOAC microwave oven drying method. This study showed that the reliability of the AOAC method was closely related to the performance of the microwave solids analyzer for tomato samples. Certification of microwave solids analyzers was recommended to assure the validity of analytical results by the AOAC method.
Comparison of Emmerie-Engel Method and Gas Chromatographic Method for Determination of Supplemental α-Tocopheryl Acetate in Feed Concentrates
Authors: Labadie Michael P , Boufford Charles E 
Published: February 2020

Abstract
The determination of supplemental a-tocopheryl acetate in high potency vitamin E powders and oils was compared using the Emmerie- Engel method and gas chromatography (GC). The Emmerie-Engel reaction requires saponification, extraction of the saponiflable fracaon, and quantitation by colorimetry. GC analysis requires only an extraction and/or dilution before quantitation. These are represented essentially by AOAC methods 43.147-43.151 (colorimetry) and 43.152-43.159 (GC) for high potency vitamin E concentrates. Each method was statistically evaluated for precision and sample-to-sample reproducibility. Each Emmerie-Engel value was divided by the GC value obtained for the same sample; an average of 1.049 with a coefficient of variation of 2.89% was obtained. It was concluded that (he GC procedure was superior to the Emmerie-Engel method, and ahould be the official procedure for determination of supplemental a-tocopheryl acetate in feed concentrates.
Simultaneous Analysis of Nivalenol and Deoxynivalenol in Cereals by Liquid Chromatography
Authors: Lauren Denis R , Greenhalgh Roy 
Published: February 2020

Abstract
A sensitive method is described for determination of nivalenol (NIV) and deoxynivalenol (DON) in cereals by using reverse phase liquid chromatography and UV detection at 222 nm. The sample is extracted with acetonitrile-water (85 + 15) and an aliquot is purified by passage through a combined column of cation exchange resin and alumina-carbon (20 + 1). Analysis at this stage is possible with some samples but the method recommends passing an aliquot through a carbon minicolumn after evaporation and solubilization in methanol. Interference from coextracted compounds at this point is negligible. Recoveries of both NIV and DON from spiked extracts taken through the full method were in the range 83-94%. The relative standard deviation, based on 5 replicate determinations from each of 2 corn samples, was approximately 5% for both NIV and DON. With a 10 fiL injection, the minimum contamination (3 x signal/noise ratio) able to be detected in cereal samples was about 0.015 μ NIV/g and 0.05 μ DON/g. The cleaned up extracts are also suitable for analysis by gas chromatography.
Identification of Mammalian Feces by Coprostanol Thin Layer Chromatography: Method Development
Authors: Hoskin George P , Bandler Ruth 
Published: February 2020

Abstract
Existing methods for the identification of mammalian fecal particles in foods have not heen completely satisfactory because visual identification of small particles is difficult. In addition, identification of feces by determining the presence of fecal alkaline phosphatase is limited to specimens in which the enzyme has not been inactivated, and it does not work well with feces from herbivores. A new method has been developed which uses coprostanol as a fecal indicator. Coprostanol is a heat-stable sterol found in the feces of mammals and some birds. A hexane extract of the suspect particle is applied to the preadsorbent zone of a silica gel thin layer chromatography plate which has been impregnated with 5% phosphomolybdic acid in ethanol. The plate is developed in diethyl ether-heptane (55 + 45), heated, and examined visually for the presence of coprostanol. Amounts of rat feces as small as 0.15 mg and cow feces as small as 0.5 mg have been identified using this method.
Determination of Desaminosulfamethazine, Sulfamethazine, and N4-Acetylsulfamethazine by Gas Chromatography with Electron Capture Detection and Confirmation by Gas Chromatography-Chemical Ionization Mass Spectrometry
Authors: Matusik Jean E , Guyer Greg C , Geleta Jaroslav N , Barnes Charlie J 
Published: February 2020

Abstract
An electron capture gas chromatographic method for the determination of sulfamethazine was modified to separate and quantitate simultaneously sulfamethazine and 2 of its metabolites, N4-acetylsulfamethazine and desaminosulfamethazine. The modified method was applied to incurred residues in a veal calf depletion study and to incurred residues in swine tissues. With capillary column gas chromatography-positive ion chemical ionization mass spectrometry, confirmation of the identities of incurred desaminosulfamethazine, N4-acetylsulfamethazine, and sulfamethazine in tissues was obtained from a single injection.
Proton Magnetic Resonance Spectroscopic Determination of Bethanechol Chloride in Tablets
Authors: Hanna George M , Lau-Cam1 Cesar A 
Published: February 2020

Abstract
A simple and reliable proton magnetic resonance spectroscopic method was developed for the assay of bethanechol chloride in tablets. The proposed method entails a minimum of procedural steps and reagents. The recovery of bethanechol chloride from synthetic formulations was 99.9 ± 0.4% (n = 15), CV = 0.4%. Mean assay values for 25 and 10 mg commercial tablets were 100.5% (n = 8) and 99.7% (» = 7) of declared, respectively. A detailed interpretation of the proton magnetic resonance spectrum is also presented.
Spectrophotometric Determination of Cyclamate in Foods: NMKL Collaborative Study
Authors: Sjoberg Anna-Maija K , Alanko Timo A 
Published: February 2020

Abstract
A spectrophotometric method for the determination of cyclamate was collaboratively studied in 9 laboratories. Ethyl acetate is added to extract cyclamate from acidic aqueous solution into water, and the cyclamate is then quantitatively converted to /V,./V-dichlorocyclohexylamine by adding excess hypochlorite. A',A'-Dichlorocyclohexylamine is determined by measuring its UV absorption at 314 nm. Six samples, 3 soft drinks with cyclamate levels of 0.36-0.47 g/kg and 3 jams with levels of 1.23-1.50 g/kg, were included in the study. Average recoveries of cyclamate were 99.7% in the soft drinks and 103.8% in the jams. Reproducibility coefficients of variation were 6.7% for the soft drinks and 4.4% for the jams.
Rapid Determination of Methyl Mercury in Fish and Shellfish: Collaborative Study
Authors: Hight Susan C 
Published: February 2020

Abstract
A modification of the official AOAC method for determining methyl mercury in fish and shellfish was studied in 8 laboratories. Methyl mercury is isolated from homogenized, acetone-washed tissue by adding HC1 and extracting into toluene the methyl mercuric chloride produced. The extract is analyzed for methyl mercuric chloride by electron capture gas chromatography. Collaborators determined methyl mercury in blind duplicate homogenates at 2 levels in tuna and at 1 level in swordfish and oysters. Collaborators also analyzed single homogenates of swordfish and oysters containing methyl mercury at a second level. Both fortified and unfortified tissues were analyzed. Methyl-bound mercury in the commodities ranged from 0.50 to 2.30 μg Hg/g. Reproducibility coefficients of variation ranged from 4 to 15%. Accuracy, measured by comparison to reference values, ranged from 92 to 101%. Recovery from fortified homogenates ranged from 86 to 98%. Reference values and unfortified levels were determined in the author's laboratory by replicate analysis of fortified
Colorimetric Determination of Tetracycline Hydrochloride in Pharmaceutical Preparations
Authors: Saha Utpal 
Published: February 2020

Abstract
A simple, sensitive, and rapid colorimetric method is presented for the estimation of tetracycline hydrochloride as the pure drug and in formulations. The proposed method is based on the reaction of tetracycline HC1 with cupric chloride in an alkaline medium to give a yellowish green solution whose absorbance is measured at 400 nm against a reagent blank. The color obeys Beer's law in the concentration range of 0-20 μg/mL. Molar absorptivity and Sandell's sensitivity of the yellowish-green copper complexes of tetracycline HC1 are 1.99 x 104 Lmol-1 cm-1 and 0.0241 ppm, respectively.
Thin-Layer Chromatographic Determination of Erythromycin and Other Macrolide Antibiotics in Livestock Products
Authors: Petz Michael , Solly Roy , Lymburn Moira , Clear Mike H 
Published: February 2020

Abstract
A method is described for determination of 4 macrolide antibiotics in livestock products. Erythromycin, tylosin, oleandomycin, and spiramycin were extracted from animal tissues, milk, and egg with acetonirrile at pH 8.5. Cleanup was done by adding sodium chloride and dichloromethane, evaporating the organic layer, and subsequent acid/ base partitioning. After the antibiotics were separated by thin-layer chromatography (TLC), they were reacted with xanthydrol and could be detected as purple spots down to 0.02 mg/kg without interference by other commonly used therapeutic drugs (23 were tested). Anisaldehyde- sulfuric acid, cerium sulfate-molybdic acid, phosphomolybdic acid, and Dragendorff s reagent proved to be less sensitive as visualizing agents. For quantitation, TLC plates were scanned at 525 nm. Recoveries were between 71 and 96% for erythromycin and tylosin in liver, muscle, and egg at the 0.1-0.5 mg/kg level and 51% for erythromycin in milk at the 0.02 mg/kg level (coefficient of variation = 10-18%). Bioautography with Bacillus subtilis was used to confirm results, in addition to TLC analysis of derivatized antibiotics and liquid chromatography with electrochemical detection. Various derivatization procedures for erythromycin were investigated for improved ultra-violet or fluorescence detection in liquid chromatography.