bluuebunny/crossref_metadata_2025_split huggingface dataset:
Radioimmunoassay of T-2 Toxin in Corn and Wheat
Authors: Lee Sungsoo , Chu Fun S 
Published: February 2020

Abstract
A radioimmunoassay (RIA) for the determination of T-2 toxin in corn and wheat was developed. The toxin was first extracted with methanol, and the methanolic extract was washed with hexane and passed through a Sep-Pak C18 reverse phase cartridge. The extract was then evaporated to remove the organic solvent, diluted with 0.1M sodium phosphate buffer (pH 7.2), and subjected to RIA using an ammonium sulfate precipitation method to separate the free T-2 toxin from the antigen-antibody complex. The recovery of T-2 toxin after the extraction and cleanup steps was 78-85% for corn and 90-95% for wheat. Sep-Pak cleanup removed a considerable amount of interfering substances from the sample, thus enabling the detection of 1 and 2.5 ppb of T-2 toxin in the wheat and corn samples, respectively. The recovery by RIA methods of T-2 toxin added to the corn and wheat samples was between 84 and 103% in the ranges of 1-20 ppb (for wheat) and 2.5-20 ppb (for corn). The new RIA proved to be a sensitive, accurate, reproducible, and relatively simple method for determining T-2 toxin.
Confirmation of Penicillic Acid by High Pressure Liquid and Gas-Liquid Chromatography
Authors: Phillips Timothy D , Ivie G Wayne , Heidelbaugh Norman D , Kubena Leon F , Cysewski Sigmund J , Hayes A Wallace , Witzel Don A 
Published: February 2020

Abstract
A pyrazoline (Py) derivative of the mycotoxin penicillic acid (PA), resulting from its reaction with diazomethane, was analyzed by high pressure liquid chromatography (HPLC) and gas-liquid chromatography (GLC). Both PA and Py-PA were chromatographed using reverse phase HPLC with a mobile phase of acetonitrile-water (60+40). An approximately 2.5-fold increase in absorbance at 254 nm and an increase in retention time of 32 s was observed with Py-PA. As an alternative means of confirmation, Py-PA could also be analyzed by GLC using flame ionization detection. This dual method should prove useful for rapid and efficient detection, quantitation, and coupled HPLC-GLC identity confirmation of low levels of PA.
Identification of Cephalosporins. II. Color Reactions and Thin Layer Chromatography
Authors: Hoogmarten Josh , Roets Eugéne E , Vanderhaeghe Hubert J 
Published: February 2020

Abstract
Some color reactions obtained with 16 commercially available cephalosporins are described. Thin layer chromatography of these cephalosporins in 17 different mobile phases is examined. Combining 2 or 3 TLC systems allows identification of all products.
High Pressure Liquid Chromatographic Determination of Sodium Fluoroacetate (Compound 1080) in Canine Gastric Content
Authors: Ray Allen G , Post Lynn O , Reagor John C 
Published: February 2020

Abstract
A sensitive high pressure liquid chromatographic method was developed for the determination of sodium fluoroacetate (compound 1080) in canine gastric content. The procedure involves extraction of 1080 with water, methyl ethyl ketone, and dilute base, followed by sample cleanup using octadecylsilane bonded phase cartridges and derivatization in ethyl acetate solution with O-p-nitrobenzyl-N-N’-diisopropylisourea (PNBDI). The compound was chromatographed on a 10 μm silica column, and ultraviolet absorbance at 254 and 280 nm was measured. Recovery was greater than 95% for standard 1080 and in the 70-90% range for spiked samples (1-50 ppm).
Determination of Trace Amounts of Nitrites in Fabricated Nonmeat Products
Authors: Desiena Anthony , Jacobs Emma , Romagnoli Ronald 
Published: February 2020

Abstract
Low levels of nitrite (1-5 ppm) contributed by raw materials in new fabricated food products were successfully determined by a modification of an AOAC method for processed meats. Recoveries were greater than 90% for composite samples to which 5-10 ppm nitrite had been added. This method allows analyses of fabricated food products containing hydrogenated vegetable oils, soy proteins, and dried egg whites for low levels of nitrite.
Survey of North Dakota Sunflower Seeds for Aflatoxin
Authors: Casper Howard H , Backer Leslie F , Kunerth Wallace 
Published: February 2020

Abstract
In a survey of oil-type sunflower seeds, 89 samples were collected from 32 storage bins in 10 counties of North Dakota in 1979. None of these survey samples exceeded the 20 ppb Food and Drug Administration aflatoxin guideline. Four research samples, from 2 grossly spoiled storages, contained 100-1100 ppb aflatoxin B1. This research is believed to be the first to document natural aflatoxin contamination in sunflower seeds.
Metal Content of Shark Muscle Powder Biological Reference Material
Authors: Taguchi Masashi , Takagi Hiroyuki , Iwashima Kiyoshi , Yamagata Noboru 
Published: February 2020

Abstract
Powdered dried shark muscle (Cephaloscyllium umbratile) is a promising biological reference material for metal analysis. Homogeneity indices (CV%) for Na, K, Zn, As, Ca, and Hg of the shark powder were within 5%. Mercury and arsenic concentrations (total Hg, 9.1 ppm dry wt, As, 99 ppm dry wt) in shark powder are relatively high. Muscle can be obtained inexpensively, and the powder can be preserved indefinitely if kept cold.
Paper Chromatographic Determination of Total Capsaicinoids in Capsicums and Their Oleoresins with Precision, Reproducibility, and Validation Through Correlation with Pungency in Scoville Units
Authors: Rajpoot Nagin C , Govindarajan Venkatesa S 
Published: February 2020

Abstract
Total capsaicinoids is an important quality index of capsicums. It has been recommended that this index can be reliably estimated by a simple and rapid paper chromatographic method. Details of the method have been critically studied to establish the precision and reproducibility. The repeatability and reproducibility of the method were ±3.12% and ±6.63% (relative to mean), respectively. In addition, the values by this method for samples of capsicums and their oleoresins, varying over a wide range of capsaicinoids content, were validated by a high correlation (r ≃ 1) to pungency values by the standardized threshold dilution method. In light of the results presented, it is suggested that the total capsaicinoids be accepted as an index of pungency.
Automated Thermal Conductivity Determination of Carbon Dioxide in Wine
Authors: Mitchell J Dale , Benjamin Christian R 
Published: February 2020

Abstract
Determination of CO2 in Lambrusco, using an automatic analyzer, has proven to be both fast and precise. The analyzer uses a thermal conductivity detector to measure CO2 gas liberated from the sample. Good accuracy was obtained when the method was compared to the enzymatic method. Ten samples gave an average difference of 1.4% from the accepted method.
Gas Chromatographic – Mass Spectrometric Determination of Volatile Organic Compounds in Fish
Authors: Easley Diane M , Kleopfer Robert D , Carasea Angelo M 
Published: February 2020

Abstract
A technique has been developed for the determination of volatile organic compounds in fish. The methodology is based on procedures used to determine purgeable organic compounds in water and wastewater. Fish tissue is added to reagent water, cooled in an ice bath, and homogenized with cell disruption using ultrasonic energy. The processed sample is then analyzed by a purge and trap procedure using an impinger-type device at 70°C, with determination of the purged compounds by computerized gas chromatography-mass spectrometry. Both ground fish and cored fish specimens were successfully analyzed by this technique. The overall average recovery for 39 volatile compounds studied was 77% with an average standard deviation of 20%.
High Performance Liquid Chromatographic Determination of Intermediates/Side Reaction Products in FD&C Yellow No. 5
Authors: Calvey Robert J , Goldberg Allen L , Madigan Elizabeth A 
Published: February 2020

Abstract
A rapid, sensitive, reproducible method that uses a strong anion exchange column and high performance liquid chromatography is described for determining intermediates/side reaction products in FD&C Yellow No. 5. With this method, 3 intermediates (sulfanilic acid, pyrazolone-T, and phenylhydrazinep- sulfonic acid) and 2 side reaction products (ethyl ester of pyrazolone-T and 4,4′-(diazoamino)dibenzenesulfonic acid) are eluted in a reproducible pattern by increasing the ionic strength of a buffered mobile phase. The intermediates sulfanilic acid and pyrazolone- T and the 2 side reaction products are quantitated; the intermediate phenylhydrazine-p-sulf onic acid is detected but not quantitated. Average recoveries for intermediates/side reaction products quantitatively determined in FD&C Yellow No. 5 samples were 99-104%. The amounts of intermediates/ side reaction products recovered were 0.005-0.18% by weight of the total sample.
Radioimmunoassay of T-2 Toxin in Biological Fluids
Authors: Lee Sungsoo , Chu Fun S 
Published: February 2020

Abstract
A simple radioimmunoassay (RIA) for detection of T-2 toxin in biological fluids was developed. The method, which involves a Sep-Pak C18 reverse phase column cleanup step before RIA, can detect 0.5 ppb T-2 toxin in serum and 2.5 ppb T-2 toxin in urine and milk. Recoveries for toxin added to serum and urine or milk samples were 87-106% in the 0.5-20 ppb range and 88-117% in the 2.5-20 ppb range, respectively. If samples were not cleaned up, false positive results prevented positive detection at concentrations less than 2.5 ppb in urine and milk.
Comparison of Methods for Determining Sodium in Fertilizers
Authors: Corominas Luis F , Boy Víctor M , Rojas Pedro 
Published: February 2020

Abstract
The AOAC official first action method, 2.147-2.150, for flame emission spectrophotometry (FES) determination of sodium in fertilizers was compared with the atomic absorption spectrophotometric (AAS) method and the sodium selective electrode (SSE) method. Ammonium oxalate, which was previously compared with water, H2SO4, HC1, and HNO3, was used to extract the sample for all 3 methods. Three synthetic NPK samples, 3 commercial samples (urea, normal superphosphate, and neutrophos), 1 phosphate rock, and 2 Magruder check samples were used for the study. Statistically significant differences were obtained in averages for most of the samples, but few differences were found in standard deviations. The AAS method showed the best accuracy and precision. Accuracy of the AOAC method is acceptable. The SSE method showed the highest deviations from the theoretical values. A collaborative study is recommended to compare the AOAC with the AAS method.
Use of Closed-System Vacuum Distillation for Isolation of Moderately Volatile Compounds
Authors: Daniels Daniel H , Warner Charles R , Birkel Thomas J 
Published: February 2020

Abstract
A rapid, efficient vacuum distillation method has been used to quantitatively determine moderately volatile compounds in food-related samples. The following components and matrices were studied: 1,4-dioxane in polysorbate 65 and choline chloride; ethylene chlorohydrin in choline chloride, choline bitartrate, and cumin; and epichlorohydrin, 1,3-dichloro-2-propanol, and l-chloro-2-propanol in cornstarch. The matrix is slurried with water or aqueous methanol, frozen, and subjected to vacuum distillation. The distillate, which is free of salts and nonvolatile matrix components, is chromatographed on a gas chromatographic column and quantitated using a flame ionization detector. Foaming, which is a problem with purge and trap and azeotropic distillation procedures, does not occur. Recoveries of the components ranged from 85 to 101% at levels of 0.5-600 ppm
Analytical Methods for Sulfonamides in Foods and Feeds. II. Performance Characteristics of Sulfonamide Methods
Authors: Horwitz William 
Published: February 2020

Abstract
Important factors in interpretation of methods for sulfonamides in tissues are value of the blank, use or omission of recovery factors, and precision of the methods. For determining sulfonamide in tissues, no interlaboratory collaborative studies have been performed to provide reproducibility parameters. By assuming comparability with other tissue residue methods at equivalent concentrations, it may be anticipated that the coefficient of variation withinlaboratories of the Bratton-Marshall method is about 15% at concentrations of a fraction of a part per million. It is estimated that the limit of reliable measurement of the Bratton-Marshall method is about 0.2 ppm, varying with the individual laboratory. This value is higher than the tolerance it is intended to enforce. Obviously, the method in this case has been stretched beyond its original claimed capabilities. This method also has high blanks and low recoveries. Assignment of sufficient resources to the solution of the problem by regulatory agencies has resulted in methods capable of handling the sulfonamide residue problem at 0.1 ppm.
Application of Chiral Lanthanide Nuclear Magnetic Resonance Shift Reagents to Pharmaceutical Analysis. II. Determination of Dextroand Levoamphetamine Mixtures
Authors: Wainer Irving W , Schneider Lynda C , Weber John D 
Published: February 2020

Abstract
Optically pure d- and l-amphetamine sulfate, as well as various mixtures of the 2 enantiomers, were analyzed using a europium chiral nuclear magnetic resonance shift reagent. The enantiomeric shift difference (ΔΔδ) exhibited by the doublet associated with the α-methyl protons was large enough to differentiate between the levo- and dextro-isomers. The α-methyl protons were decoupled and the enantiomeric composition was determined by using the peak heights of the resulting singlets. As little as 5% of the levo-isomer in the presence of the dextro-isomer can be determined using this method. The method is applicable to the analysis of bulk drug and pharmaceutical preparations.
Gas-Liquid Chromatographic-Thermal Energy Analyzer Determination of N-Nitrosodimethylamine in Beer at Low Parts per Billion Level
Authors: Sen Nrisinha P , Seaman Stephen 
Published: February 2020

Abstract
A gas-liquid chromatographic (GLC) procedure is described for the determination of low ppb levels of N-nitrosodimethylamine (NDMA) in beer. The sample is treated with sulfamic acid under acidic conditions followed by alkalinization with dilute KOH, distillation at atmospheric pressure, extraction of NDMA from alkaline aqueous distillate with dichloromethane, concentration of dichloromethane extract by Kuderna-Danish concentrator, and, finally determination by a GLC-thermal energy analyzer technique with N-nitrosodipropylamine (NDPA) as an internal standard. The method gave results comparable with 2 other well established methods. Recoveries of added NDMA, N-nitrosodiethylamine, and NDPA at levels ranging from 0.08 to 10 ppb were 75-112, 86-115, and 85-109%, respectively. Five replicate analyses of a beer sample gave a mean NDMA concentration (corrected for recovery) of 2.21 ± 0.08 ppb (± SD). Minimum detection limit of the method is about 0.1 ppb.
Bacitracin Determination in Feeds: Evaluation of Methods
Authors: Ragheb Hussein S 
Published: February 2020

Abstract
Assay of bacitracin activity in feeds is subject to many sources of variation. Bacitracin standards are complex mixtures and may contain various amounts of less active forms of bacitracin. Test organisms may respond differently to these mixtures. Collaborative studies should involve the use of one standard, perhaps USP zinc bacitracin. The use of different types of bacitracin standards (regular or zinc) in a laboratory may contribute to variation in sample potency. The pyridine extraction method is subject to serious operational difficulties. Among the contributing factors are incomplete evaporation of pyridine (causing positive bias), allowing the temperature to increase too much during evaporation (causing negative bias), and the numerous manipulative steps in the technique (causing large variability). Because of these factors and the toxic properties of pyridine, the method finds little use. Methanol extraction offers a better substitute for determining zinc or methylene disalicylate bacitracin in premixes and complete feeds by the plate method.
Determination of Aflatoxin B1 in Corn, Wheat, and Peanut Butter by Enzyme-linked Immunosorbent Assay and Solid Phase Radioimmunoassay
Authors: El-Nakib Ossama , Pestka James J , Chu Fun S 
Published: February 2020

Abstract
Determinations of aflatoxin B1 in corn, wheat, and peanut butter by an enzyme-linked immunoassay (ELISA) and a solid-phase radioimmunoassay (RIA) were compared. Samples spiked with 2.9-43.2 ppb B1 were subjected to AOAC extraction procedure 26.017 or 26.023. The extracts were concentrated, redissolved in methanol, diluted in phosphate-buffered saline with Tween 20, and directly analyzed for B1 by either ELISA or RIA. At 5.8 ppb or greater, recoveries for B1 in corn, wheat, and peanut butter samples were 80.0,86.6, and 94.8% by ELISA and 61.0, 93.3, and 110.0% by RIA, respectively. Recoveries greater than 120% were obtained for the wheat and peanut butter samples spiked with 2.9 ppb aflatoxin B1 by the RIA method but not by ELISA. Overall results indicated that ELISA gave more consistent data, relatively lower standard deviations, and lower coefficients of variation than did RIA. Analysis of 3 samples naturally contaminated with aflatoxins revealed that the ELISA data were comparable to those obtained by other established chemical methods.
Stable Isotope Ratio Determination of the Origin of Vanillin in Vanilla Extracts and Its Relationship to Vanillin/Potassium Ratios
Authors: Martin Glenn E , Alfonso Felipe C , Figert Donald M , Burggraff James M 
Published: February 2020

Abstract
A method is described for isolating vanillin from vanilla extract, followed by stable isotope ratio analysis to determine the amount of natural vanillin contained in adulterated vanilla extracts. After the potassium content is determined, the percent Madagascar and/or Java vanilla beans incorporated into the extract may then be approximated from the vanillin/ potassium ratio.
Nuclear Magnetic Resonance Spectroscopic Determination of Methoxyflurane
Authors: Henry Kermit W 
Published: February 2020

Abstract
A simple, rapid nuclear magnetic resonance (NMR) spectroscopic method for quantitatively determining methoxyflurane was developed. The proton NMR spectrum of methoxyflurane in carbon tetrachloride exhibited a well defined triplet at 5.67 ppm and a sharp singlet at 3.68 ppm. Using dimethyl sulfoxide (DMSO) as an internal standard, methoxyflurane was quantitated by comparing the integral for the singlet of methoxyflurane with the integral for the singlet of DMSO at 2.60 ppm. The method was accurate to concentrations as low as 1‑2%, and results agreed with those obtained by the NF XIV method
Ethylene Dibromide Residues in Biscuits and Commercial Flour
Authors: Rains Diane M , Holder James W 
Published: February 2020

Abstract
Flour and biscuit samples from a school lunch program were analyzed for ethylene dibromide (EDB). Flour samples were extracted with hexane at room temperature with maximum extraction of EDB in 4 days. Biscuits were extracted by steam distillation with hexane; optimum recoveries were obtained by a triple extraction of the sample. Recoveries of EDB from flour and biscuits ranged from 85 to 103% as determined by gas-liquid chromatography on a 15% OV-17 column and a 63Ni electron capture detector. Random samples were confirmed by gas chromatography- mass spectrometry. From &lt;8 ppb to 4 ppm EDB were determined in flour and &lt;0.5 ppb to 260 ppb in biscuits. Possible sources for the higher values are discussed.
Jack Bean Meal as Source of Urease in Determination of Urea
Authors: Hoover William L , Melton James R 
Published: February 2020

Abstract
Ground jack bean was added to feed samples as a source of urease in urea determinations. Jack bean meal is much less expensive and is more stable in the presence of soluble salts than is refined urease powder. Percent recoveries in terms of protein equivalent for 3 types of feed ranged from 96.1 to 98.9, using the proposed method. Jack bean meal was equal or superior to refined urease powder in converting urea to ammonia in all samples analyzed.
Template for Marking Thin Layer Chromatographic Plates for Two-Dimensional Development
Authors: Gardner Albert M 
Published: February 2020

Abstract
A compact template for marking 200 × 200 mm thin layer chromatographic (TLC) plates for 2-dimensional TLC is described. Directions are provided for use of the easily fabricated apparatus. The template permits rapid, accurate, and reproducible marking of plates for application of samples and standards
High Performance Liquid Chromatographic Method for Pyrantel Tartrate in Swine Feeds and Supplements
Authors: Goras John T 
Published: February 2020

Abstract
A new method for the determination of pyrantel tartrate in swine feed and supplements has been developed because the current official AOAC method is not applicable to feeds co-medicated with tylosin. The new method involves: (a) leaching of drug from feed with methanolic NaCl solution, (b) removal of interfering substances by ion pair liquid-liquid extraction and high performance liquid chromatography, and (c) quantitation of pyrantel tartrate by monitoring the ultraviolet absorption of the effluent stream at 313 nm. The method of standard addition is used to compensate for the effect of the feed matrix on drug recovery. No interference is encountered from tylosin, carbadox, lincomycin, non-drug components of feeds and supplements, or potential degradation products of pyrantel tartrate, i.e., cis isomer of pyrantel tartrate and (E)-N(3-methylaminopropyl)-2-thiopheneacrylamide. Results for the assay of 3 lots each of feeds and supplements containing 0.0106 and 0.106% pyrantel tartrate, respectively, were within ±4% of label claim. Coefficients of variation ranged from 1.6 to 1.8% for feeds and from 1.9 to 3.9% for supplements.
Determination of 2,4-D Butoxyethanol Ether Ester and Its Degradation Products 2,4-Dichlorophenoxyacetic Acid and 2,4-Dichlorophenol in Sediment
Authors: Kan Gordon Y P , Mah Fred T S , Wade Norman L , Bothwell Max L 
Published: February 2020

Abstract
2,4-D butoxyethanol ether ester (2,4-D BEE) was isolated from sediment by extraction with acetonehexane at neutral conditions; from the same sediment sample, 2,4-dichlorophenoxyacetic acid (2,4-D) was isolated with methanol after the sediment had been acidified to &lt; pH 2. 2,4-Dichlorophenol in the sediment was extracted with isooctane by steam distillation. Mean recoveries from 4 spiked samples ranged from 99 to 108%, 94 to 102%, and 74 to 76% for 2,4-D BEE, 2,4-D, and 2,4-dichlorophenol, respectively. These procedures were developed for routine analyses of lake sediments in the Okanagan region of British Columbia.
Chromatographic Separation of Polar and Nonpolar Components of Frying Fats
Authors: Waltking Arthur E , Wessels H 
Published: February 2020

Abstract
A method is proposed to assess deterioration of frying fats by measuring polar and nonpolar components separated on a silica gel column. Means for polar components measured in duplicate samples by 19 collaborators ranged from 8.0 ± 0.34 to 25.8 ± 0.90%. Coefficients of variation ranged from 3.5 to 4.9%. The method has been adopted as official first action.