bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aflatoxin Levels in Airborne Dust Generated from Contaminated Corn During Harvest and at an Elevator in 1980
Authors: Burg William R , Shotwell Odette L 
Published: February 2020

Abstract
Bulk corn samples and airborne samples generated therefrom were collected on a Georgia farm during the 1980 harvest and while the 1980 corn was being ground and fed to swine. The bulk corn harvested had 1640 ng total aflatoxin/g. Airborne dust samples collected at the front of the combine had an average of 3850 ng total aflatoxin/g; at the side of the combine, the average aflatoxin level was 2550 ng/g of dust. At one time, the operator was exposed to airborne dust containing 1360 ng/g while inside the combine cab. An airborne dust sample taken with a personal sampler during transfer of the corn to a truck had 52 000 ng/g. Airborne dusts collected while corn containing aflatoxin (1240- 1850 ng/g) was being ground and fed had total aflatoxin levels ranging from nondetected to 43 700 ng/g. Airborne dust, bulk corn, and settled dust samples were collected at a grain elevator. Airborne dust samples collected during the delivery of corn in farm trucks to the elevator had an average of 1240 ng total aflatoxin/g. The airborne dust samples taken while corn was being unloaded from the elevator into trucks and railroad cars had lower average aflatoxin levels than those in dusts collected during delivery. Settled dusts in the elevator had 173-669 ng total aflatoxin/g. The highest aflatoxin level in the air in the elevator was 13 000 ng/cu. m near the conveyor belt. Airborne dust samples collected by personal samplers on elevator workers contained aflatoxin levels of 429-1300 ng/g; aflatoxin levels in the air were .9-1120 ng/cu. m.
Comparison of Liquid Chromatography and High Performance Thin Layer Chromatography for Determination of Aflatoxin in Peanut Products
Authors: Tosch Donna , Waltking Arthur E , Schlesier John F 
Published: February 2020

Abstract
Recent research studies concerning aflatoxin in peanut products have involved the use of new instrumental methods for greater detection sensitivity. A comparison of 2 such techniques, liquid chromatography (LC) and high performance thin layer chromatography (HPTLC), is reported here. With respect to precision, accuracy, sensitivity, recovery, and linearity of response, HPTLC appears to be equivalent to LC. These points illustrate the viability of HPTLC as an alternative technique in the determination of aflatoxin.
Reverse Phase Liquid Chromatographic Determination of Aspartame in Beverages and Beverage Mixes
Authors: Webb Norma G , Beckman Darrell D 
Published: February 2020

Abstract
A method is described for determining the artificial sweetener aspartame in beverages and beverage mixes by liquid chromatography. Aspartame is separated on a μC18 column, using a mobile phase of acetic acid, water, and isopropyl alcohol at pH 3.0 and UV detection at 254 nm. Beverages are filtered through 0.45 μm filters and injected directly into the chromatograph. Aspartame is eluted in approximately 7 min. Detection of aspartame is confirmed by a UV scan of the trapped peak. Aspartame is quantitated in the presence of other beverage additives such as saccharin, caffeine, sodium benzoate, artificial colors, and artificial flavors. Results are presented for spiked soda beverages, beverages from fruit-flavored mixes, instant tea, reconstituted presweetened drink mixes, and a powdered tabletop sweetener.
Practical Screening Procedure for Chloramphenicol in Milk at Low Parts per Billion Level
Authors: Schwartz Daniel P , McDonough Frank E 
Published: February 2020

Abstract
A relatively simple screening procedure for the detection of chloramphenicol in cow’s milk is detailed. The drug in 50 mL skim milk is adsorbed onto Chromosorb 102 and subsequently eluted; interfering impurities are removed by passing the effluent directly over one column containing small beds of alumina and cation exchange resin in the H+ form. After solvent is removed, the nitro group of the drug is reduced with zinc dust in HCI, and the drug is detected by diazotization and coupling to N-1-(naphthyl)ethylenediamine. Milk containing ≥4 ppb chloramphenicol can be detected. A number of antibiotics and sulfa drugs permitted for use with dairy cows do not interfere with chloramphenicol detection, nor do some naturally occurring aromatic amino compounds. Nitromide (3,5-dinitrobenzamide) will interfere. It is estimated that approximately 50 samples of skimmed milk can be screened by one person during the working day. Cows secreted the drug into their milk for approximately 3 days following injection of chloramphenicol either intramuscularly or via infusion into the udder.
Gas Chromatographic-Mass Spectrometric Detection and Quantitation of Lincomycin in Animal Feedingstuffs
Authors: McMurray Cecil H , Blanchflower W John , Rice Desmond A 
Published: February 2020

Abstract
A substantially Improved assay was developed for lincomycin A in animal feedingstuffs. The assay allows unambiguous quantitation of at least 0.1 ppm in feed. Lincomycin B did not interfere because of differences in both retention time and mass of the main fragment ion in electron impact (EI) spectra. The assay using single ion monitoring with EI detection would not discriminate between lincomycin A and clindamycin. The presence of the latter was easily confirmed by using gas chromatography-mass spectrometry in the chemical ionization mode. The assay for lincomycin A was linear in the range 0–40 ng applied to the gas chromatographic column. The recovery was 93.4 ± 4.2% at 1 and 5 ppm and 86.2 ± 5.5% at 0.1 ppm in feed. The coefficient of variation of the assay was 4.8% at both 1 and 5 ppm, and was 6.43% at 0.1 ppm.
Available Amino Acid Score for Evaluating Protein Quality of Foods
Authors: Sarwar Ghulam 
Published: February 2020

Abstract
Amino acid scores corrected for true digestibility of individual amino acids (as determined by rat balance method) were termed “available amino acid scores” in the present investigation. Available amino acid scores were calculated for 7 protein sources and their 10 supplementary or complementary mixtures which have been tested in collaborative amino acid and rat growth assays for evaluating protein quality. The available amino acid scores were as follows: casein + methionine (100); egg white (100); rapeseed protein concentrate, RPC (94); casein (93); beef (89); soya assay protein, SAP (62); pea flour (61); whole wheat flour, WW (38); SAP + methionine (88); pea flour + methionine (72); WW + lysine (67); WW + casein (84); WW + egg white (79); WW + RPC (65); WW + beef (77); WW + SAP (70); and WW + pea flour (75). These scores were similar to the collaborative relative NPR values; the differences were less than 10 units (2–9 units) in most cases. The positive correlation (r = 0.92) between available amino acid scores and relative net protein ratio (RNPR, a rat growth method) values was highly significant (P &lt; 0.01) and the origin of the regression line (y = 0.92x + 1.88) was not significantly different from zero. Amino acid bioavailability has previously been a problem, preventing widespread acceptance of amino acid score. Available amino acid score solves this problem.
Stored Wheat Insect Infestation Related to Uric Acid as Determined by Liquid Chromatography
Authors: Wehling Randy L , Wetzel David L , Pedersen John R 
Published: February 2020

Abstract
Liquid chromatography is used to measure the uric acid content of wheat internally infested by various growth stages of granary weevil (Sitophilus granarius), rice weevil (Sitophilus oryzae), and lesser grain borer (Ryzopertha dominica). Good correlation exists between numbers of insects and uric acid content of grain infested by a given stage of an internally infesting stored product insect, with correlation coefficients ranging from 0.970 to 0.998. Uric acid content of infested grain increases as the insect life cycle progresses, with granary weevil producing the greatest quantities of uric acid followed in order by rice weevil and lesser grain borer. A detection limit for the analytical procedure of less than 1.0 ppm uric acid allows detection of infestation levels as low as one kernel per 100 g grain for late instar granary weevil larvae. This limit is sufficiently sensitive to detect levels of infestation that may be commonly encountered in commerce.
Semiautomated Determination of Tridihexethyl Chloride in Meprobamate Tablets
Authors: Kirchhoefer Ross D 
Published: February 2020

Abstract
A semiautomated method has been developed for the analysis of tablets containing tridihexethyl chloride in combination with meprobamate. The method is based on the USP assay for tridihexethyl chloride in tablets. The active ingredient is dissolved in water, the aqueous solution is mixed with buffer and dye solution, and the dye complex is extracted into chloroform. The absorbance of the chloroform solution is monitored at 408 nm. Results from the semiautomated method agree with I results for the USP method. Recoveries from authentic formulations I show no interference from the excipients tested.
Liquid Chromatographic Determination of Oxfendazole in Swine Feeds
Authors: Shah Gaman , Bradley Dorothy , Shek Efraim 
Published: February 2020

Abstract
A relatively simple analytical method is presented for determination of oxfendazole (2-(methoxycarbonylamino)-5-phenylsulfinyl-benzimidazole) at levels as low as 0.012% in swine feeds, using cation exchange liquid chromatography (LC). The sample was extracted with a solvent mixture of methanol-glacial acetic acid (90 + 10) at 45°C, using a gyrorotory shaker. Plant pigments and other feed excipients were removed using zinc acetate treatment and pH-controlled extraction. Oxfendazole was further separated from the remaining interferences and quantitatively determined by LC on a Partisil SCX column with acetonitrile-1.01M phosphate buffer as mobile phase. The method is stability-specific, linear, precise, and accurate at 80-120% labeled strength (relative standard deviation 0.9-1.7 with mean recovery of 98-99%). Supporting data at a level of 0.0135% oxfendazole in swine feed indicated that this method is capable of complete recovery of oxfendazole from medicated swine feeds.
Liquid Chromatographic Analysis of Sugars, Acids, and Ethanol in Lactic Acid Vegetable Fermentations
Authors: Mcfeeters Roger F , Thompson Roger L , Fleming Henry P 
Published: February 2020

Abstract
Routine analysis of all the major substrates and products of homolactic or heterolactic acid vegetable fermentations was made possible by the use of 2 liquid chromatographic procedures. Sucrose, glucose, fructose, and mannitol were determined on a cation exchange column in the lead form. The coefficient of variation of the added compounds (2 to 30mM) in fermented cucumber juice with salt concentrations of 0-1.5% ranged from 2.0 to 3.1%. Sucrose (l-12.5mM), malic acid, lactic acid, acetic acid, and ethanol (2-25mM) added to cucumber juice containing 0- 6.0% NaCl were separated on a reverse phase column; coefficients of variation ranged between 4.3 and 5.9%. Sample preparation requires only blending and filtration prior to injection.
Liquid Chromatographic Determination of Flavor Enhancers and Chloride in Food
Authors: Nguyen Thanh T , Sporns Peter 
Published: February 2020

Abstract
A liquid chromatographic method is described for the simultaneous determination of flavor enhancers (glutamate, inosine-5'-monophosphate, and guanosine-5'-monophosphate) and chloride (salt) added to food. This rapid method exhibits excellent recoveries, and does not require derivatization or gradient elution by refractive index and UV detection in series.
Improved Storherr lube for Assisted and Sweep Co-Distillation Cleanup of Pesticides, Poly chlorinated Biphenyls, and Pentachlorophenol from Animal Fats
Authors: Neidert Eli , Saschenbrecker Peter W 
Published: February 2020

Abstract
A procedure is presented for the simultaneous extraction from animal fat and quantitation of 15 pesticide residues, 4 polychlorinated biphenyl (PCB) formulations, and pentachlorophenol (PCP). Silanization of the Storherr tube packing reduces thermal decomposition and allows for residue recoveries in excess of 88% from pork, beef, chicken, sheep, and rabbit fat. This Storherr tube performs well in either the assisted distillation or sweep co-distillation mode of operation. Detection limits of 2-5 ppb for the pesticides and 10 ppb for the PCBs are readily attained.
Chemical Derivatization Analysis of Pesticide Residues. VIII. Analysis of 15 Chlorophenols in Natural Water by In Situ Acetylation
Authors: Lee Hing-Biu , Weng Li-Da , Chau Alfred S Y 
Published: February 2020

Abstract
A rapid analytical method is presented for quantitative analysis of 15 chlorophenols in natural waters by in situ acetylation. In the presence of KHC03, phenols in water are acetylated by acetic anhydride directly without pre-extraction. The resultant acetates are extracted by petroleum ether and analyzed by electron capture gas chromatography. The investigation to optimize the conditions for in situ acetylation of these phenols is also described. This method has been validated and shown to be applicable over a range from 100 to 0.01 ppb with a 1 L water sample.
Gas Chromatographic Method for Analysis of 2,4-D in Wheat: Interlaboratory Study
Authors: Smith Allan E 
Published: February 2020

Abstract
A procedure is described for the determination of 2,4-D (2,4-dichlorophenoxyacetic acid) in dried green plant material. Samples are first extracted with dilute sodium hydroxide, and then after acidification and solvent extraction, the residues are methylated using boron trifluoride-methanol reagent. The methyl ester of 2,4-D is cleaned up on a Florisil column and quantitated using a gas chromatograph equipped with an electron capture detector. Six laboratories made quadruplicate determinations on control, dried green wheat check samples, on 4 similar samples fortified at the 0.50 ppm level, and on 4 samples fortified at the 1.00 ppm level with 2,4-D. Based on the data from 5 laboratories, the plant fortifications of 0.50 and 1.00 ppm yielded average interlaboratory recoveries of 2,4-D of 83.3 and 88.2%, respectively. The procedure also has potential for the determination of 2,4-D in wheat straw and wheat grain.
Simple Analytical Method for Organophosphorus Pesticide Determination in Unpolished Rice, Using Removal of Fats by Zinc Acetate
Authors: Adachi Kazuhiko , Ohokuni Nobuyuki , Mitsuhashi Takao 
Published: February 2020

Abstract
A rapid and simple method is developed for the determination of organophosphorus pesticides in unpolished rice. The new method incorporated acetonitrile-water (1 + 1) extraction, removal of fats by zinc acetate, and further cleanup on an activated charcoal chromatographic column. The higher fatty acids in the extract react rapidly with zinc acetate to form insoluble zinc carboxylates, which precipitate. Additional interferences were cleaned up on an activated charcoal chromatographic column, and organophosphorus pesticides adsorbed on the activated charcoal were eluted with acetone-hexane. Dimethoate is not retained on the activated charcoal and must be extracted with dichloromethane from the first acetonitrile-water eluate. Pesticides are measured by flame photometric gas chromatography. Recoveries from 50 g unpolished rice samples fortified with 5-50 μg diazinon, 6-30 μg parathion, 8-40 μg fenitrothion and IBP, 10-50 μg dimethoate and fenthoate, 20-100 μg malathion, or 40-200 μg EPN ranged from 75.7 to 95.8%.
Enumeration of Total Coliforms, Fecal Coliforms, and Escherichia coli in Foods by Hydrophobic Grid Membrane Filter: Supplementary Report
Authors: Entis Phyllis 
Published: February 2020

Abstract
Raw, comminuted poultry meat was used to determine the specificity of the media and incubation conditions used in the hydrophobic grid membrane filter method. Confirmation rates for target colonies were 100% for total coliforms, 98% for fecal coliforms, and 97-99% for Escherichia coli. The results of total coliform enumeration in 30 pasteurized milk samples by both the hydrophobic grid membrane filter method and AOAC method 46.013-46.016 are also reported.
Liquid Chromatographic Determination of Glucosinolates in Rapeseed as Desulfoglucosinolates
Authors: Sang Joseph P , Truscott Roger J W 
Published: February 2020

Abstract
A method was developed for the quantitative determination of rapeseed glucosinolates as the desulfo derivatives, using liquid chromatography. Glucosinolates were desulfated at 37°C with the enzyme aryl sulfatase in Tris buffer, pH 8.0. All glucosinolates present in rapeseed were separated in 30 min on a Waters C18 Z-module using an acetonitrile gradient at 4 mL/min. Recoveries of benzyl, 4-hydroxybenzyl, and allylglucosinolates added to plant extracts were quantitative.
Simultaneous Determination of Thiamine and Riboflavin in Foods by Liquid Chromatography
Authors: Augustin Jorg 
Published: February 2020

Abstract
Recent methods for determination of thiamine (thiochrome) and riboflavin by liquid chromatography (LC) are outlined and discussed, and a new method allowing the simultaneous determination of these 2 vitamins by using a single fluorescence detector is described. This system involves an ODS 5 μm ultrasphere column and a pH 7.5 mobile phase composed of 0.005M tetrabutyl ammonium phosphate in methanol-water (20 + 80).
Determination of Folacin m Foods and Other Biological Materials
Authors: Gregory III Jesse F 
Published: February 2020

Abstract
The objective of most methods for determination of folates in foods and other biological materials is to estimate the total folacin content of the sample. Because folacin comprises a diverse group of related compounds exhibiting similar biological activity, the analytical method must be capable of measuring all of the folates. Methods have been developed for separation of folates in their monoglutamy 1 form by using anion-exchange, paired-ion reverse phase, or conventional reverse phase liquid chromatography (LC). The application of these separations to determination of folates in foods and other biological materials has been limited largely by the need for development of adequate preparative methods and sufficiently sensitive and specific detection procedures. Although LC with ultraviolet absorption detection has been successful in certain limited applications, the development of fluorometric detection methods has permitted LC determination of folates in a wide range of materials. Tetrahydrofolic acid and its substituted derivatives are detected by monitoring their native fluorescence in an acid mobile phase, while folic acid and certain other folates are measured by using an oxidative post-column fluorogenic derivatization system. Methods also have been developed for determination of the polyglutamyl chain length distribution of folates in biological materials. In total, these procedures permit a direct determination and characi terization of folacin compounds.
Forage Nitrate Analysis: Laboratory Performance Study
Authors: McMahon Terence L , Casper Howard H 
Published: February 2020

Abstract
Four forage samples were analyzed by 16 laboratories for KNO3 content. Individual reported KNO3 values varied widely for each sample; coefficients of variation for the 4 samples were 36.0, 51.0, 12.8, and 55.0%. Recovery of KNO3 from the spiked sample averaged 105%. The analytical results, as a group, were unacceptable both statistically and for use in feeding recommendations. Three values reported could have resulted in feeding potentially toxic forage to livestock.
Microbiological Determination of Neomycin in Feeds and Formulated Products
Authors: Stahl Gerald L , Kratzer Dal D 
Published: February 2020

Abstract
An AOAC modified method is described for the microbiological assay of neomycin, which has been adapted to include complete feeds, supplements, premixes, liquids, oil suspensions, boluses, and antibiotic-impregnated paper. The method features a more sensitive standard response line with a monolayer plating system. The use of a buffered plating medium in place of the water-prepared medium results in a curve with less degree of slope, which allows for more accurate interpretation of the standard response. The feed extract diluent used for standard response line dilution, which is prepared from exposure of the feed extract fluid to pH changes, heat, and sodium hypochlorite, has been eliminated. The constant salt concentration diluent used for the preparation of standards is the same as the salt concentration of the sample extract solution to be tested. Results for 50 commercial complete feeds and 50 commercial premixes received over the last 5 years produced an overall mean recovery of 101% with a mean percent recovery range of 80-112%. A statistical analysis of these 100 commercial, complete feeds and premixes, ranging in concentration from 47 g/ton to 70 g/lb, indicates the assay has little, if any, concentration-related bias. Precision and accuracy of the method was supported by laboratory studies of 20 assays that produced a mean recovery of 101 % and standard deviation of 3.
Gas Chromatographic Determination of Residues of Bromopropylate and Two of Its Degradation Products in Honey
Authors: Formica Giuseppe 
Published: February 2020

Abstract
An analytical procedure is described for determination of residues of bromopropylate (BP) and its main degradation product 4,4'-dibromobenzophenone (BBP) in honey. The method also allows the determination of 4,4'-dibromobenzilic acid (BBA), a potential intermediate to BBP. The method involves dissolution of the honey in water and separation of BP and BBP from BBA on a partition column. BP and BBP are further cleaned up and separated on a silica gel column and determined by gas chromatography (GC) with electron capture (EC) detection. BBA is oxidized with potassium dichromate to BBP, which is partitioned into dichloromethane and further cleaned up on a silica gel column before determination by GC with EC detection. The method is sensitive to 0.02 mg BP or BBP/kg and 0.023 mg BBA/kg honey.
Liquid Chromatographic Determination of Phenol and Cresols in Total Particulate Matter of Cigarette Smoke
Authors: Tomkins Bruce A , Jenkins Roger A , Griest Wayne H , Reagan Roberta R , Reagan Roberta R , Holladay Susan K 
Published: February 2020

Abstract
The phenol and cresol contents of the total particulate matter of tobacco smoke can be conveniently determined. A simple extraction procedure using IN base is followed by partial neutralization with glacial acetic acid and elution of hydroxy benzenes from an end-capped reverse phase liquid chromatographic column. The procedure is rapid (20 min/sample after the initial extraction), precise (± 10% relative standard deviation), accurate, and convenient. Normally, 12 or fewer cigarettes are needed for a single measurement.
Reduction in Variability of Instrumental Methods
Authors: Horwitz William 
Published: February 2020

Abstract
The largest contribution to experimental error in most analyses is systematic, resulting from preparation of standards and calibration procedures. By their very nature, systematic errors are difficult to detect and measure, particularly without interlaboratory comparisons. It is suggested that systematic errors can be reduced by incorporating reference physical constants (such as molar absorptivity) and certified standards to verify the correctness of the calibration curve and the standard solutions from which they were constructed.