bluuebunny/crossref_metadata_2025_split huggingface dataset:
Differential Pulse Polarographic Determination of Iodine in Foods and Nutritional Products
Authors: Thompson Donald , Lee Susan , Allen Rebecca 
Published: February 2020

Abstract
A differential pulse polarographic procedure is described for the analysis of iodine in foods and nutritional products. Samples with iodine concentrations ranging from 5000 to 0.2 ppm have been successfully analyzed using this procedure. Precision averaged between 2 and 10% relative to the iodine level measured. Recoveries of added iodine ranged from 89 to 108% with external standards, and 97-100% by an analyte additions technique. Samples analyzed include dried almonds, whey protein concentrate, nonfat dried milk, sea kelp, vitamin-mineral nutritional supplements, diet meal replacement products, dried green beans, dried mushrooms, and wheat germ.
Add Methanolysis and Gas Chromatographic Determination of Brominated Vegetable Oils in Soft Drinks
Authors: Lawrence James F , Chadha Rajinder K , Conacher Henry B S 
Published: February 2020

Abstract
A gas chromatographic method has been developed for determination of brominated vegetable oils in citrus-flavored soft drinks. Oils were extracted from the drinks with ethyl ether and subjected to acidcatalyzed methanolysis. The resulting brominated methyl esters (dibromostearate, tetrabromostearate, and hexabromostearate) were separated and quantitated as single peaks on a 3% OV-3 column. Chromatography columns were stable for about 3 months of daily use; then the first 15 cm of column packing material was replaced or a new column was prepared. A number of citrus soft drinks were analyzed and contained 3.5-3.9 mg brominated oil/10 fl. oz. Recoveries from spiked samples after organic extraction and methanolysis were 94.5-105%.
Alcohol Proof Determination from Absolute Specific Gravity (20°C/20°C) Using Oscillating U-Tube Digital Density Meter with Programmable Calculator
Authors: Stewart LeRoy E 
Published: February 2020

Abstract
Proof determination using a digital density meter has been difficult at temperatures other than 60°F because no single table for conversion exists as does for apparent specific gravity. The instrument operates more satisfactorily and temperature stability is easier to achieve at temperatures closer to ambient. Because 20°C is widely accepted by the scientific community as the temperature for calibration of equipment and standardization of tests, that temperature was chosen as the basis for the program the author has written to convert specific gravity (20°C/20°C) to proof. AOAC Table 52.003 was the source of data for this program. A table relating specific gravity (20°C/20°C) to proof was also generated from the formula of the International Organization of Legal Metrology (IOLM). Proofs determined using the calculator program and the tables of AOAC, IOLM, and NBS compare favorably.
First-Derivative Spectroscopic Determination of Acetaminophen and Sodium Salicylate in Tablets
Authors: Tobias David Y 
Published: February 2020

Abstract
A first-derivative spectroscopic method for the simultaneous determination of acetaminophen and sodium salicylate in tablets was developed. Solutions of this drug combination in acidic ethanol were analyzed using their respective spectral responses at 258.5 and 317.0 nm. The method, which can be used for tablet composite assay and content uniformity analysis, is linear for acetaminophen concentrations ranging from 0.0 to 21.6 μ/mL, and for sodium salicylate concentrations ranging from 0.0 to 36.0 μ/mL. Relative standard deviations for the assay of both drugs in commercial tablets were &lt;2%, and recoveries of acetaminophen and sodium salicylate from spiked samples were 99.7 and 100.1%, respectively. The results obtained by first-derivative spectroscopy were in agreement with the results of a liquid chromatographic procedure for acetaminophen and a fluorometric method for sodium salicylate. The technique used for the selection of wavelengths for analysis is also described.
Enzyme-Linked Immunosorbent Assay of Ochratoxin A in Barley
Authors: Morgan Michael R A , Mcnerney Ruth , Chan Henry W-S 
Published: February 2020

Abstract
A noncompetitive, double antibody enzyme-linked immunosorbent assay for ochratoxin A using microtitration plates has been developed and applied to samples of barley. The anti-ochratoxin A antiserum, which is used at high dilution, does not cross-react significantly with ochratoxin B or ochratoxin α, Assay sensitivity for determination of the toxin in barley samples is 60 ng/kg. Minimal sample preparation is required before assay.
Brine Saturation Technique for Extracting Light Filth from Canned Crabmeat and Shrimp: Intralaboratory Study
Authors: Freeman Clarence C 
Published: February 2020

Abstract
An intralaboratory study was made of a new technique for isolating light filth from canned shrimp and crabmeat. Recoveries of 93.8% for insect fragments and 89.4% for rodent hair plus the brevity and simplicity of the new technique make it superior to the 2 existing official methods for these products.
Identification and Semiquantitation of Monensin Sodium in Animal Feeds by Thin Layer Bioautography
Authors: Martinez Elizabeth E , Shimoda Wilbert 
Published: February 2020

Abstract
A bioautographic technique for the determination of monensin sodium contamination in animal feeds is described. The feeds are extracted in aqueous methanol and the initial monensin extracts are isolated by filtration through an alumina column. These eluates are partitioned between 5% NaCl and methylene chloride, and are further purified through a Sephadex LH-20 column. A 10 mL eluate containing the monensin is collected from the Sephadex column and evaporated, and the residue is dissolved in methylene chloride. Aliquots are spotted on a thin layer plate and monensin is detected by a thin layer bioautographic technique, using Bacillus subtilis as the test organism. The reliable limit of sensitivity is 100 ppb, but 10 ppb can be detected. This technique can be used to semiquantitate monensin by comparing the zones of inhibition of unknown test samples against monensin standards.
Liquid Chromatographic Determination and Mass Spectrometric Confirmation of Chloramphenicol Residues in Animal Tissues
Authors: Bories George S F , Peleran Jean-Claude , Wal Jean-Michel 
Published: February 2020

Abstract
A rapid and sensitive liquid chromatographic (LC) method for determination of trace amounts of chloramphenicol (CP) in animal tissues has been developed. Chloramphenicol identity is confirmed by gas chromatography-mass spectrometry (GC-MS). CP can be routinely quantitated by LC at 10 ppb with 75% recovery, and GC-MS selected ion monitoring permits complete identification at concentrations as low as 5 ppb. Residues were determined in chicken tissues after intramuscular injection of CP. Depletion was rapid with no residues detected in muscle after 8 h, while 15-30 ppb CP was still determined and identified in the liver.
Fluoride Ion-Selective Electrode Determination of Sodium Monofluoroacetate in Meat Baits and Formulations
Authors: Livanos George , Milham Paul J 
Published: February 2020

Abstract
Hot aqueous alkaline conditions were used to delluorinate sodium monofluoroacetate (Compound 1080) with a mean efficiency of 98% and a coefficient of variation of 2%. The liberated fluoride was determined by ion-selective electrode. These procedures were used to analyze meat baits and commercial 1080 formulations. Compound 1080 (1–50 mg) was extracted from meat baits into 50% (v/v) acetone–water by blending, followed by ultrasonic agitation and digestion on a steam bath. The extract was filtered and the solids were agitated ultrasonically in more extracting solvent. The combined extracts were concentrated by evaporation prior to alkaline hydrolysis. This technique was well adapted to processing the large sample sizes encountered during analysis of whole baits (&lt;400 g). After correction for co-extracted inorganic fluoride, the typical recovery was 86% with a coefficient of variation &lt;7%. Proprietary 1080 formulations (&gt;90% w/w powders) were simply dissolved in water and diluted before alkaline hydrolysis. Recoveries for added reagent grade material, after correction for free fluoride, averaged 97% with a coefficient of variation 2%.
Capillary Gas Chromatographic Determination Products of Naphthalene in Bran and Wheat Germ
Authors: Kacprza Jurgen L , Robert Geyer , Chongchit Cooper 
Published: February 2020

Abstract
A method is described for determining naphthalene in bran and wheat germ products. The method involves distilling the naphthalene from a water–cereal mixture and then extracting the distillate with hexane. A 10 μL aliquot of the hexane extract is injected into a gas chromatograph equipped with a capillary column. Dodecan-l-ol is used as the internal standard. Mean recoveries, standard deviations (SD), and coefficients of variation (CV) for samples of unprocessed bran, unprocessed wheat germ, bran flakes breakfast cereal, and sultana bran breakfast cereal, spiked with naphthalene at various levels, were 1.0 ppm spike, mean 0.98, SD 0.09, CV 9.5%; 2.5 ppm spike, mean 2.37, SD 0.22, CV 9.4%; 5.0 ppm spike, mean 4.86, SD 0.19, CV 4.0%; 10 ppm spike, mean 9.25, SD 0.38, CV 4.1%. The mean recoveries exceeded 90% in each case. The detection limit for the method was about 0.5 ppm.
Recommended Modification of Dilution Procedure Used for Bacteriological Examination of Shellfish
Authors: Cook David W , Pabst Gerard S 
Published: February 2020

Abstract
The dilution procedure recommended by the American Public Health Association for use in bacteriological analysis of shellfish samples may cause an underestimation of the number of bacteria in shellfish. Modifications of that procedure to include preparation of the first dilution of the shellfish homogenate on a weight rather than a volume basis, and the inoculation of 1 g portions of the shellfish from a dilution of the homogenate, have been shown to significantly increase the recovery of fecal coliform bacteria from oyster samples. It is recommended that these modifications be adopted by the American Public Health Association.
Reverse Phase Liquid Chromatographic Determination of Intermediates and Subsidiary Colors in D&C Green No. 5
Authors: Bailey John E 
Published: February 2020

Abstract
A reverse phase liquid chromatographic method is presented for the simultaneous determination of 2-amino-5-methylbenzenesulfonic acid, 5-amino-2-methylbenzenesulfonic acid, External D&C Violet No. 2, and the lower sulfonated subsidiary color in D&C Green No. 5. The method uses octadecylsilanized silica gel as the stationary phase and gradient elution with a mobile phase of aqueous acetonitrile solutions containing ammonium acetate. A wide dynamic range is achieved in a single analysis with quantitation of the intermediates at relatively low levels, up to 0.2% (w/w) each, and subsidiary colors at relatively high levels, up to 3.0% (w/w) each. In addition, the method separates the 3 primary disulfonated isomers of D&C Green No. 5 as well as numerous unidentified components. The results of a recovery study and a survey of 16 commercial samples and the pharmacology sample are presented. Recoveries of the intermediates and subsidiary colors from samples of D&C Green No. 5 ranged from 96.8 to 103.8%. The calibration and recovery data are treated statistically to evaluate the performance of the method.
Evaluation of Capillary Gas Chromatography for Pesticide and Industrial Chemical Residue Analysis. I. Comparison of Retention Ratios Obtained on Methyl Silicone-Coated Capillary Columns with Published Values for Packed Columns
Authors: Fehringer Norbert V , Walters Stephen M 
Published: February 2020

Abstract
Many residue laboratories use the retention ratio data compiled by the Food and Drug Administration in its Pesticide Analytical Manual (PAM) for the tentative identification of pesticide and industrial chemical residues detected in food samples. These data were compiled using packed gas chromatographic columns. A study was undertaken to determine if these retention ratios could be used when applying capillary gas chromatography to residue analysis. Retention ratios of a selected group of 108 of the materials listed in the PAM tables were determined isothermally with split injection on 4 WCOT capillary columns obtained from 3 commercial suppliers and coated with 4 different methyl silicone coatings. Of the tested reference materials, 90 displayed retention ratios that matched the PAM values on all columns, 10 differed on at least one of the 4 columns, and only omethoate and monocrotophos gave retention ratios differing on all 4 columns.
Net Protein Ratio Data: AACC-ASTM Collaborative Study
Authors: Happich Muriel L , Bodwell C E , Ross Hackler L , Phillips John G , Derse Philip H , Elliott Elliott G , Hartnagel Ralph E , Hopkins Daniel T , Kapiszka Eugene L , Mitchell Geraldine V , Parsons Grace F , Prescher Elmer E , Robaidek Eugene S , Womack Madelyn 
Published: February 2020

Abstract
Seven- and 14-day net protein ratio (NPR) data were obtained from 7 laboratories for 6 protein sources: ANRC casein, lean beef, Iactalbumin, textured vegetable protein, and peanut flour were fed as 10% protein (N × 6.25) in the test diet. Wheat flour, casein, and textured vegetable protein were fed as 6% protein (N × 6.25) in the test diet. Weighed dry ingredients for each diet were sent to each collaborator, who mixed the dry ingredients, then added specified amounts of corn oil and water and mixed each complete diet thoroughly. Rats were adapted for 0, 2, or 4 days, and then were fed the test diets for 28 days for protein efficiency ratio (PER) diets. The animal weight gain and feed consumption data obtained after 7 or 14 days of feeding were used to calculate NPR values. Analyses of data were done before [net protein ratio (NPR)] and after (R-NPR [relative-NPR]) adjustment of the data from each laboratory by its results for the reference protein casein. From the analysis of variance for NPR, significant (P &lt;0.05) interactions were observed among laboratories, protein sources, and adaptation times of the animals (0,2, or 4 days). Inter- and intralaboratory variability were decreased by use of 14-day values compared with 7- day values. Adjustment of the NPR data to R-NPR did not lower the intralaboratory variability but did lower the interlaboratory variability of the data. Increasing adaptation time did not consistently decrease interlaboratory or intralaboratory variability or decrease coefficients of variation (CV) of R-NPR values. The 14-day NPR inter- and intralaboratory variations for the 10 % protein diet over all factors (5 protein diets, 3 adaptation periods, and 7 laboratories), as measured by CV values, were 13.2 and 7.7%, respectively. The corresponding R-NPR values were 9.2 and 8.0%, respectively.
Gas Chromatographic Determination of Ametryn and Its Metabolites in Tropical Root Crops
Authors: Bardalaye Promode C , Wheeler Willis B 
Published: February 2020

Abstract
Residue analysis of the herbicide ametryn (2-methyIthio-4-ethylamino-s-isopropylamino-s-triazine) is widely known but an analytical method for determining its metabolites has not yet been reported in the literature. A method has been developed for the extraction and determination of ametryn and 3 metabolites, 2-methylthio-4-amino-6-isopropylammo- s-triazine (GS-11354), 2-methylthio-4,6-diamino-.s-triazine(GS- 26831), and 2-methylthio-4-amino-6-ethylamino-s-triazine (GS-11355) in taniers, yams, cassava. Residues were extracted from crops with ethyl acetate-toluene (3 + 1 v/v), using a Polytron homogenizer and anhydrous sodium sulfate added for drying. The extracts were cleaned up by automated gel permeation chromatography on Bio-Beads SX-3 gel in the same solvent system. Quantitative determination was performed by gas chromatographic (GC) analysis on a column packed with 5% DEGS-PS on 100-120 mesh Supelcoport using either an N-P detector or a flame photometric detector (FPD) in the sulfur mode. Minimum detection by the flame photometric detector is 10 ng each for ametryn, GS-11354, and GS-11355 and 21 ng for GS-26831; by the N-P detector, 0.3 ng of each component gives easily quantitatable peaks. On a parts per million basis, starting with 25 g sample, the FPD detected a minimum level of 0.04 p.g/g each for ametryn, GS-11354, and GS-11355, and 0.08 p.g/g for GS-26831. The N-P detector could detect 0.0024 p.g/g for all 4 compounds. In addition to superior sensitivity, instrumental conditions allowed the complete separation of components in 10 min, for the N-P detector; more than 30 min was required for the FPD. Recoveries from fortified crops ranged from 67 to 111% at levels of 0.1-1.0 μg/g.
Recent Advances in Cleanup of Fats By Sweep Co-Distillation. Part 1: Organochlorine Residues
Authors: Luke Barry G , Richards Jeffrey C , Dawes Ernest F 
Published: February 2020

Abstract
A redesigned fractionation tube has resulted in development of a new, commercial sweep co-distillation unit. It is compact, reliable, costefficient, and permits cleanup of pesticides in up to 10 fat samples simultaneously. Recovery of several organochlorine residues (HCB, ; BHC, lindane, heptachlor epoxide, dieldrin, p,p'-DDE, p,p'-DDD, p,p'-DDT) at ppm and ppb levels in meat (beef) fat are 83-105%, with coefficients of variation between 4 and 6%. Cleaned up extracts are quantitated by gas chromatography using an electron capture detector with a vitreous silica capillary column containing a medium polarity bonded phase.
Liquid Chromatographic Determination of the Plant Estrogens Coumestrol and Isoflavones in Animal Feed
Authors: Pettersson Hans , Kiessling Karl-Heinz 
Published: February 2020

Abstract
A simplified procedure is described for the cleanup and determination of the 5 main plant estrogens in animal feed: coumestrol, genistein, biochanin A, daidzein, and formononetin. The estrogens are extracted with ethanol and purified on a Sep-Pak C18 cartridge. All 5 plant estrogens are separated in an isocratic liquid chromatographic system and quantitated by UV and fluorescence responses. The method is sensitive to about 2.5 ppm coumestrol and 10 ppm of the isoflavones.
Capillary Gas Chromatographic Determination of Pentachlorophenol Residues in Tallow Following Automated Gel Permeation Cleanup
Authors: Lee Barbara E , Lacroix Mario D , Dupont Guy A J , Scott James A 
Published: February 2020

Abstract
A gas chromatographic method for the determination of pentachlorophenol (PCP) in tallow is described. Samples are melted and mixed with the solvent used for automated gel permeation chromatographic (GPC) cleanup. The methyl ether derivative of PCP is prepared by treating the appropriate GPC fraction with an ethereal solution of diazomethane. The extract is further cleaned up on Florisil, and the PCP methyl ether is easily identified and quantified by capillary column gas chromatography (GC) with electron capture detector. The detection limit was 0.001 ppm in tallow. Recoveries varied from 80 to 107% over the fortification range of 0.005–0.05 ppm. Capillary GC-high resolution mass spectrometry is used to confirm PCP methyl ether in the sample extract.
Evidence for Transformation of Sulfamethazine to its N4-Glucopyranosyl Derivative in Swine Liver During Frozen Storage
Authors: Parks Owen W 
Published: February 2020

Abstract
An analytical procedure for determining N4-glucopyranosylsulfamethazine (GPS) in swine livers is described. The sulfamethazine derivative is extracted from the tissues with water. GPS is isolated in sufficient purity for liquid chromatographic determination by a series of adsorption chromatographic procedures. Recovery of the conjugate from spiked swine livers was 82.2% with a coefficient of variation of 4.5%. Evidence is presented suggesting that sulfamethazine in swine livers is transformed to GPS during frozen storage. Two samples of swine liver in which incurred sulfamethazine residues were substantially depleted during frozen storage were analyzed for GPS. The conjugate accounted for 96.2% and 92.2% of the depleted sulfamethazine residues.
Comparison of AOAC and EEC Methods for Determining Available P2O5 in Fertilizer
Authors: Johnson Frank J , Parks Kenneth L 
Published: February 2020

Abstract
Three interlaboratory studies are described in which AOAC method 2.053 was compared with the neutral ammonium citrate method for direct available P2O5 recommended by the European Economic Community (EEC). The initial study comprised 5 laboratories and 7 samples. Significantly more available P205 was found by the AOAC method in 5 of 7 samples tested. Fifteen laboratories analyzed 8 samples in the second study; only 2 samples yielded more P2O5 by the AOAC method. The final study included 9 samples and 14 laboratories. Results for the AOAC method were higher on 4 samples. Conclusions reached from the 3 studies are (1) The AOAC method gave consistently higher values for available P2O5, especially for triple superphosphate samples; and (2) the difference between methods increased with increasing amounts of citrate-insoluble P2O5. All data were reported to the International Standards Organization Working Group on phosphorus in fertilizer.
Apparent Nitrogen Digestibility Data: AACC–ASTM Collaborative Study
Authors: Happich Muriel L , Bodwell C E , Hackler L Ross , Phillips John G , Derse Philip H , Elliott James G , Hopkins Daniel T , Parsons Grace F , Prescher Elmer E , Robaidek Eugene S 
Published: February 2020

Abstract
Apparent nitrogen digestibility data were obtained from 4 laboratories for 6 protein sources and 2 diet levels, 6 and 10% protein, after a 2-day adaptation period during the AACC–ASTM protein efficiency ratio (PER) and net protein ratio (NPR) collaborative studies. For 5 protein sources fed as 10% of the diet, the interlaboratory variation as measured by coefficient of variation (CV) values was low (1.5–3.5%), indicating high precision of the method. Wheat flour (6% protein diet) had the highest variation and, therefore, the lowest precision (CV of 7.10%). The interlaboratory variation (CV value) for 3 of the 4 laboratories was considerably lower, less than half that for the 4 laboratories. An analysis of variance of apparent nitrogen digestibility data indicated significant (P &lt;0.05) effects for the 4-Iaboratory group due to laboratories and protein diets at both 10 and 6% protein levels, and for the 3-laboratory group at the 10% protein level. The 3-laboratory ANOVA for the 6% diets indicated a significant effect (P &lt;0.05) due to diet only.
Performance Characteristics of Methods of Analysis Used for Regulatory Purposes. I. Drug Dosage Forms. B. Gas Chromatographic Methods
Authors: Horwitz William , Albert Richard 
Published: February 2020

Abstract
Gas chromatographic methods for the analysis of drug dosage forms consist of a simple extraction, dilution with an internal standard solution, and injection, or, even simpler, dilution with the internal standard solution and injection. These methods were used in 7 collaborative studies of the determination of 12 pharmaceuticals, published in the Journal of the AOAC during 1973–1983. A total of 43 individual materials consisting of various dosage forms were each analyzed, usually in duplicate, by an average of 8 laboratories, with a total of 582 reported determinations. The average within-laboratory coefficient of variation (CVo) was 1.25% and the average among-laboratories coefficient of variation (CVx) was 2.41%, for a CVo/CVx ratio of 0.52, at an average outlier rate of 1.4% of the reported values. The line of best fit for CVx plotted against concentration increases with decreasing concentration, extending from a CVx of approximately 1.8% at 100% concentration to a CVx of approximately 3.2% at 1% concentration. The change in CVx for a 10-fold decrease in concentration is approximately 0.7% CVx, independent of analyte and matrix.