bluuebunny/crossref_metadata_2025_split huggingface dataset:
Production of Antibodies and Development of Enzyme Immunoassay for Determination of Monensin in Biological Samples
Authors: Mount Michael E , Failla Douglas L 
Published: February 2020

Abstract
Monensin is converted to monensin bromoacetate, which provides successful coupling to protein and allows production of monensinspeciflc rabbit antisera. A modified indirect enzyme-linked immunosorbent assay (ELISA) was developed, which is highly sensitive (2 ng/mL) to monensin determination. Monensin recovery was 53- 81% at 10 ppb in sera or urine, and 81-130% at 100 ppb in dichloromethane- extracted feces or water. Overall recovery was 98.8% with coefficients of variation from 6 to 52% over the range of monensin concentrations studied. This is the first immunoassay reported for the carboxylic ionophore antibiotics.
Quantitative Liquid Chromatography of Ampicillin: Collaborative Study
Authors: Margosis Michel 
Published: February 2020

Abstract
A previously published liquid chromatographic method proposed for official use for the analysis of ampicillin in the market place was subjected to an international collaborative study. The method is rigorously defined in terms of performance requirements, yet allows a degree of flexibility to the individual analyst. Twenty-four participating laboratories from 9 countries submitted results of analysis of 3 samples. The data from one laboratory were rejected because they failed to meet the prescribed performance criteria. Evaluation of the data shows a coefficient of variation less than 1.8% between laboratories for each sample.
Purge and Trap Method for Determination of Volatile Halocarbons and Carbon Disulfide in
Table-Ready Foods
Authors: Heikes David L 
Published: February 2020

Abstract
A method developed for the determination of ethylene dibromide in table-ready foods has been modified and expanded to include 7 other volatile halocarbons and carbon disulfide. Samples are stirred with water and purged with nitrogen for 0.5 h in a water bath at 100°C. The analytes collected on a duplex trap composed of Tenax TA and XAD-4 resin are eluted with hexane and determined by gas chromatography with electron capture detection or Hall electrolytic conductivity detection. Flame photometric detection in the sulfur mode is used to determine carbon disulfide. Thick-film, wide-bore capillary columns are used exclusively in both the determination and confirmation of the halogenated analytes. The higher levels of analytes are also confirmed by full scan gas chromatography mass spectrometry (GC/MS). Samples are analyzed for carbon disulfide, methylene chloride, chloroform, 1,2-dichloroethane, methyl chloroform, carbon tetrachloride, trichloroethylene, 1,2-dibromoethane, and tetrachloroethylene. Initially, 19 table-ready foods from the Food and Drug Administration's Total Diet Study were analyzed by this method. A limited survey of those food items exhibiting high levels of analytes was conducted. Samples exhibited levels up to 3300 ppb (methyl chloroform in Parmesan cheese). Recoveries of all 9 analytes from fortified samples ranged from 83 to 104%. Chromatograms from this purge and trap method are clean, enabling quantitation levels of low parts per billion and sub-parts per billion to be achieved for the halogenated analytes. The quantitation limit for carbon disulfide is 12 ppb. Two compounds found in drinking water were identified by GC/MS as bromodichloromethane and chlorodibromomethane. Drinking water from several cities was analyzed for these trihalomethanes as well as for bromoform. Levels of up to 17 ppb bromodichloromethane were found. Recoveries ranged from 96 to 103%.
Capillary Gas Chromatographic Analysis of Amino Acids by Enantiomer Labeling
Authors: Bayer Ernst , Frank Hartmut , Gerhardt Jürgen , Nicholson Graeme 
Published: February 2020

Abstract
The optical isomers of amino acids can be easily separated by gas chromatography using capillary columns coated with the chiral polysiloxane peptide, Chirasil-Val. Quantitative trace amino acid analysis in complex mixtures such as biological fluids, sea water, or protein hydrolysates can be achieved by enantiomer labeling: The D-amino acid enantiomers, which do not occur naturally, are added to the sample prior to analysis as internal standards. Because the D-enantiomers show the same physical and chemical properties as the natural L-enantiomers, they are ideal standard references. In routine analysis, the derivatization is achieved with a new automated derivatization robot. The D-standard serves as overall internal standard for the whole analytical procedure from sample enrichment to derivatization, chromatography, and response of the detector.
Ion-Exchange Separation of Amino Acids with Postcolumn Orthophthalaldehyde Detection
Authors: Ashworth Raymond B 
Published: February 2020

Abstract
Moore's and Stein's classical ion-exchange separation of amino acids remains the standard by which all methods are judged. The adaptation of liquid chromatography (LC) equipment to amino acid analysis was inevitable because microprocessor control of gradients allowed almost infinite variation in gradient shape, producing superior resolution with only 2 buffers. The versatility of LC equipment allowed the instruments to be used for other assays. Adaptation of orthophthalaldehyde (OPA) to amino acid analysis increased detection sensitivity to the picomole range. A method for essential amino acids analysis in mechanically separated red meat and poultry products has been adapted to liquid chromatography using postcolumn hypochlorite oxidation, OPA derivatization, and fluorescence detection. Separation is achieved with 2 sequential concave exponential gradients combining ionic strength and pH increases with halidecontaining buffers. Hydroxyproline and proline are detected with increasing sensitivity through the use of 3-mercaptopropionic acid in a stabilized OPA reagent. Sample preparation is a critical part of the method. A defatting procedure removes fat and other nonprotein nitrogenous substances. The hydrolysis procedure is designed to protect tryptophan which can be routinely assayed in hydrolysates with a modified flow program. Corrosion damage to the equipment by halide buffers has brought about a search for alternative methodology.
Liquid Chromatographic Determination of Salinomycin Sodium in Feed Premix and Biomass Samples
Authors: Dimenna Gary P , Creegan James A , Turnbull Lennox B , Wright George J 
Published: February 2020

Abstract
A liquid chromatographic (LC) method has been developed for determination of sodium salinomycin (SS) in feed premix and biomass samples. SS is extracted from samples with acetonitrile, and the extract is diluted to volume. An aliquot is then injected directly into the chromatographic column, and refractive index detection is used to determine the presence of SS. The LC method proved to be both fast and specific; SS was quickly separated from lasalocid, monensin, and narasin. To test the efficiency of this extraction method, premix and biomass samples were spiked with SS. The mean recovery of SS from the spiked premix samples was 101.6%, and from the spiked biomass samples, 99.4%. Six premix samples were then assayed for SS in triplicate on 5 successive days, and 10 biomass samples were assayed for SS in triplicate on 3 different days. The coefficients of variation for the premix assay values ranged from 2.50 to 7.87%. For the biomass assay, CVs ranged from 0.9 to 3.5%. Premix and biomass samples were assayed for SS by this LC method in 2 laboratories and by a turbidimetric method using Bacillus subtilis in a third laboratory. The assay values obtained for SS were equivalent.
DNA Hybridization Assay for Detection of Salmonella in Foods: Collaborative Study
Authors: Flowers Russell S , Joan Klatt Mary , Mozola Mark A , Curiale Michael S , Gabis Damien A , Silliker John H 
Published: February 2020

Abstract
A collaborative study was performed in 11 laboratories to validate a DNA hybridization (DNAH) procedure for detection of Salmonella in foods. The DNAH procedure was compared to the standard culture method for detection of Salmonella in 6 foods: ground pepper, soy flour, dry whole egg, milk chocolate, nonfat dry milk, and raw deboned turkey. With the exception of turkey which was naturally contaminated, uninoculated and inoculated samples of each food group were analyzed. Results for the DNAH method were significantly better than for the standard culture method at the 5% probability level for the detection of Salmonella in turkey. There was no significant difference between the methods for the other 5 foods. The method has been adopted official first action.
Enzyme Immunoassay for Detection of Salmonella in Low-Moisture Foods: Collaborative Study
Authors: Flowers Russell S , Joan Klatt Mary , Robison Barbara J , Mattingly Jerome A , Gabis Damien A , Silliker John H 
Published: February 2020

Abstract
A collaborative study was performed in 15 laboratories to evaluate a modification of the enzyme immunoassay (EIA) method for detection of Salmonella in foods (46.B21-46.B29). The modified EIA requires 18-24 h pre-enrichment, 6-8 h selective enrichment, and 14-18 h M-broth post-enrichment prior to performing the assay, which requires 1-2 h. Total assay time is 40-52 h. The modified method was compared with the standard culture method for detection of Salmonella in 5 low-moisture foods: nonfat dry milk, milk chocolate, meat and bone meal, dry whole egg, and ground pepper. The modified method has been adopted official first action for use with low-moisture foods.
Determination of Ergotamine Tartrate in Tablets by Liquid Chromatography with Fluorescence Detection
Authors: Cieri Ugo R 
Published: February 2020

Abstract
A method is presented for the liquid chromatographic (LC) determination of ergotamine tartrate in tablets that is applicable even in the presence of other ingredients such as phenobarbital, belladonna alkaloids, and caffeine. The sample is transferred to a volumetric flask, a small volume of formic acid is added to dissolve and stabilize the ergotamine, and the solution is diluted to volume with methanol. The solution is mixed and filtered through paper. The LC system consists of a Rheodyne injector fitted with a 20 μL loop and a C,18 reverse phase column; the mobile phase is acetonitrile-water-triethylamine (700 + 300 + 0.5). Ergotamine tartrate is determined fluorometrically at an excitation wavelength of 250 nm and an emission wavelength of 430 nm. Recovery studies were conducted at the 0.3 and 1.0 mg levels. Average recoveries were 99.6 and 100.8%, respectively; relative standard deviations (RSDs) were 1.08 and 2.21%, respectively. Some commercial preparations containing ergotamine tartrate in combination with other ingredients were also analyzed. The RSDs for 5 determinations of each of 2 ground composites were 0.09 and 0.34%.
Spectrophotometric Determination of Aminacrine Hydrochloride in Creams, Jellies, and Suppositories: Interlaboratory Study
Authors: Bunch Elaine A 
Published: February 2020

Abstract
A previously reported visible spectrophotometric method for the analysis of aminacrine hydrochloride in creams, jellies, and suppositories was studied collaboratively by 8 laboratories. Aminacrine hydrochloride was extracted into acidic ethanol and its visible spectrum recorded. The amount present was calculated by determining the net absorbance between the absorbance maximum at about 402 nm and one-half the sum of the absorbance of the minima at about 389 and 412 nm. Each collaborator received 4 creams (0.2%), 1 jel (0.2%), 1 molded suppository (6 mg/3.198 g), and 2 gelatin-encapsulated suppository samples (12 mg/6.661 g and 14 mg/6.863 g). The cream samples included blind duplicates prepared to contain 0.212% aminacrine hydrochloride, 15% sulfanilamide, and 2% allantoin. Mean recovery for the authentic cream was 104.7% with a coefficient of variation (CV) of 9.22%. The commercial products contained these respective amounts (CVs): creams, 100.0% (2.48%) and 101.5% (2.16%); jel, 118.0% (9.58%); molded suppository, 102.7% (1.88%); and gelatin encapsulated suppositories, 93.1% (1.0%) and 94.3% (1.60%). Standard aminacrine hydrochloride provided for the study was 99.6% pure by nonaqueous titration. Thin layer chromatographic identification of aminacrine hydrochloride was also tested collaboratively. The method was not adopted by AOAC.
Reverse Phase Liquid Chromatographic Determination of Some Food Additives
Authors: Veerabhadrarao Madduri , Narayan Mandayam S , Kapur Omprakash , Sastry Chilukuri Suryaprakasa 
Published: February 2020

Abstract
Liquid chromatographic methods are described for the separation and determination of non-nutritive sweeteners, namely, acesulfame, aspartame, saccharin, and dulcin; preservatives such as benzoic acid and p-hydroxybenzoic acid; and caffeine and vanillin in ready-toserve beverages, ice candy, ice cream, squash beverage, tomato sauce, and dry beverage mix samples. These additives are separated on a ^Bondapak C18 column using methanol-acetic acid-water (20 + 5 + 75) as mobile phase and detected by UV absorption at 254 nm. Caffeine, vanillin, dulcin, and benzoic acid can be analyzed quickly by using a mobile phase of methanol-acetic acid-water (35 + 5 + 60). Aspartame can be separated in the presence of caffeine and vanillin by using the mobile phase pH 3 acetate buffer-methanol (95 + 5). Retention factors and minimum detectable limits are described. The percentage error and the percent relative standard deviation for 6 replicate samples ranged from 0.3 to 2.8 and from 1.64 to 3.60, respectively. Recovery of additives added to the foods named and analyzed by the direct method and by extraction ranged from 98.0 to 100.6% and from 91.6 to 101.8%, respectively. The proposed LC techniques are simple, rapid, and advantageous because all the additives can be detected in a single step, which makes it useful for the routine analysis of various food products.
Improved Efficiency for Colorimetric Determination of Furfural in Citrus Juices
Authors: Beeman Curt P 
Published: February 2020

Abstract
The operational efficiency of a method for colorimetric determination of furfural in citrus juices is improved by inclusion of a concentrationscreening step prior to the color reaction. The absorbance at 277 nm may be used to determine the appropriate dilution for samples exceeding the recommended maximum furfural concentration in the reaction mixture. As much as 1 h per sample may be saved in the time required for analysis.
Liquid Chromatographic Identification of Common Fish Species
Authors: Osman Magdi A , Ashoor Samy H , Marsh Paul C 
Published: February 2020

Abstract
Water-soluble sarcoplasmic proteins in aqueous blends of each of 31 fresh fish species were separated and quantitated by a simple liquid chromatographic (LC) method. The method revealed major qualitative and quantitative differences which were used for reliable identification of all species. Freezing for 6 months had no apparent effect on water-soluble fish proteins and did not change species-specific chromatograms. Cooking, however, caused significant changes which resulted in chromatograms different from those of fresh or frozen samples. Fish species identification by the LC method is rapid (total analysis time is about 1 h) and reliable and does not require special skills. It is applicable to fresh and frozen whole, sliced, filleted, and minced fish.
Detection and Quantitation of T-2 Mycotoxin in Rat Organs by Radioimmunoassay
Authors: Hewetson John F , Pace Judith G , Beheler Joanne E 
Published: February 2020

Abstract
A standard radioimmunoassay was compared with radiochromatography for the ability to detect unlabeled T-2 mycotoxin in organs from exposed animals. When 10% of HT-2, the only known metabolite that cross-reacts with T-2, was included and expressed as T-2 equivalents in the radiochromatographic detection, correlation between toxin detection in liver, spleen, and kidney by the 2 techniques was r = 0.98. An unknown metabolite was detected in heart extract by radiochromatography. Inclusion of this material in the T-2 equivalents detected by radiochromatography indicated a near-perfect correlation (r = 0.95; p &gt; 0.05; slope = 0.82; y = intercept = 72) among all 4 tissues.
Use of Solid-Phase Extraction Systems to Improve the Sensitivity of Artemia Bioassays for Trichothecene Mycotoxins
Authors: Hoke Steven H , Carley C Michael , Johnson Eugene T , Broski Florence H 
Published: February 2020

Abstract
Solid-phase extraction was used to preconcentrate trichothecene mycotoxins from rivers and streams in order to develop and improve a rapid and sensitive bioassay using the brine shrimp Artemia salina. For T-2 toxin, HT-2 toxin, and 4,15-diacetoxyscirpenol, LCM values obtained were 172, 600, and 700 μg/L, respectively. The LC50 for 4-deoxynivalenol was 21 mg/L. A more than 5-fold increase in sensitivity was observed when solid-phase extraction (SPE) was used in conjunction with the Artemia bioassay. For T-2 toxin, HT-2 toxin, and 4,15-diacetoxyscirpenol, LC50/SPE values after solid-phase extraction were 21, 83, and 130 μg/L. The use of river and stream waters and chlorinated water did not seem to interfere with the bioassay.
Total Organic Carbon as an Index for Specification of Water for Injection
Authors: Matsuda Rieko , Ishibashi Mumio , Uchiyama Mitsuru , Hiraoka Tamio , Hoshida Haruhiko , Kunihiro Yasuyuki , Miki Hiromichi , Nishimoto Yukio , Inazu Kunihei , Mizuno Takanori , Watanabe Ryozo , Yano Kokuji 
Published: February 2020

Abstract
Determination of organic compounds present as contaminants in purified water is of great importance. Total organic carbon (TOC) may be a useful parameter for evaluating the purity of water. This paper describes and compares the analytical results for solutions of 12 model compounds obtained by 3 methods: total organic carbon (TOC) analysis, determination of potassium permanganate consumption, and UV spectroscopy. TOC analysis gave values corresponding to the expected amounts of organic carbon for all the model compounds, whereas the other 2 methods gave highly variable results.
Quantitative Determination of Linoleic Acid in Infant Formulas by Gas Chromatography
Authors: Lee Theresa W 
Published: February 2020

Abstract
A method has been developed for the quantitative determination of linoleic acid in infant formulas by gas chromatography (GC). A known amount of triheptadecanoin was spiked into the sample. Total lipid was extracted from the product by an ethyl ether-petroleum etherethanol system in a Mojonnier flask. The sample was saponified by methanolic KOH after the solvents were evaporated. Methyl esters of the fatty acids were prepared by boron trifluoride (BF3) in methanol and analyzed by gas chromatography. A glass column packed with 10% SP-2340 (75% cyanopropyl silicone) was used to separate and identify the methyl linoleate and the methyl heptadecanoate. The quantity of methyl linoleate was calculated by comparing the integrated peak areas of these 2 fatty acid methyl esters. This method was satisfactory for both milk protein-based and soy protein-based matrixes. The results obtained by this method are comparable to those obtained by the AOAC spectrophotometric method 28.082- 28.085.
Gas Chromatographic/Mass Spectrometric Determination of Erythromycin in Beef and Pork
Authors: Takatsuki Keigo , Suzuki Shigeru , Sato Nobutoshi , Ushizawa Isamu , Shoji Takuro 
Published: February 2020

Abstract
A gas chromatographic/mass spectrometric (GC/MS) method is described for the determination of residual erythromycin in beef and pork. This method allows detection and quantitation of residual erythromycin in beef and pork by using single-ion monitoring; confirmation by a full scan electron impact mass spectrum is possible if residual level in a sample is ≥ 1 ppm. Erythromycin is extracted with methanol from a sample and cleaned up by n-hexane washing followed by partition between chloroform and phosphate buffer solution. The cleaned up extract is chromatographed on a silica gel column, acid hydrolyzed, and acetylated in acetic anhydride-pyridine mixture (1 + 2) at room temperature. The reaction mixture is injected into the GC/MS apparatus, and detection and quantitation are conducted using single-ion monitoring at m/z 200. The recoveries (CV, %) at 1 and 0.1 ppm fortification levels are 86% (2.7%) and 72% (7.7%), and the detection limit is 0.01 ppm.
Gas Chromatographic, Liquid Chromatographic, and Titrimetric Procedures for
Determination of Glycerin in Allergenic Extracts and Diagnostic Antigens: Comparative Study
Authors: Del Grosso Alfred V , May Joan C 
Published: February 2020

Abstract
Three methods for the determination of glycerin are examined as applied to several allergenic extracts and diagnostic antigens. The liquid chromatographic procedure uses a sulfonic acid functional PSDVB resin (Aminex HPX-87H), a mobile phase of 0.013N H2S04; and refractive index detection. The titrimetric procedure involves oxidation of glycerin with sodium metaperiodate followed by potentiometric titration of the resulting formic acid with sodium hydroxide. Samples are quantitated by comparing the equivalence point obtained from the sample to those obtained from a series of standards. The gas chromatographic procedure includes a column of 5% Carbowax 20 M on 80-100 mesh Chromosorb WHP; p-cresol was used as an internal standard. The 3 procedures are shown to be valid for the majority of product types examined. A positive interference was encountered in the titrimetric analysis of a tuberculin purified protein derivative that contained simple sugars. Recoveries of added glycerin ranged from 95.0 to 100.2% by the liquid chromatographic method, from 98.7 to 101.4% by the gas chromatographic method, and from 99.8 to 101.6% by the metaperiodate oxidation method when interference from simple sugars was not present. Coefficients of variation determined from 8 replicates of samples that contained glycerin were 2.2% or less for the liquid chromatographic method, 2.3% or less for the GC method, and 3.6% or less for the metaperiodate oxidation method.
Reverse Phase Liquid Chromatographic Determination of Dexamethasone Acetate and
Cortisone Acetate in Bulk Drug Substances and Dosage Forms: Method Development
Authors: Ng Linda L 
Published: February 2020

Abstract
The determination of the steroid acetates was evaluated for ruggedness of the method by using an octyldecylsilane column, 254 nm detection, and acetonitrile-water as mobile phase. Mobile phase pH, oven temperature, and columns from various manufacturers had no dramatic effect on the chromatography. The method was then optimized for dexamethasone acetate and cortisone acetate bulk drug and dosage forms. For dexamethasone acetate, the bulk drug substance should be dried at 105°C before use, and the sample should be dissolved in 50% acetonitrile-buffer pH 6 for stability. Cortisone acetate, on the other hand, was found to be nonhygroscopic and hence could be used as received. For stability, the sample should be stored in 50% acetonitrile-buffer pH 4