bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fish Species Identification by Isoelectric Focusing: Sarcoplasmic Protein Polymorphism in Monkfish (Lophius americanus)
Authors: Lundstrom Ronald C 
Published: February 2020

Abstract
Monkfish (Lophius americanus) sarcoplasmic protein patterns were found to be polymorphic with respect to separations using isoelectric focusing. Reproducible protein pattern variations were not detected using cellulose acetate or polyacrylamide gel disc electrophoresis. Monkfish sarcoplasmic proteins separated on pH 3.5-9.5 Ampholine PAGplates or on pH 2.5-9.0 agarose IEF gels yielded similar patterns showing 3 distinct, reproducible variations. On close examination, the pH 3.5-9.5 Ampholine PAGplate patterns could be further subdivided into 3 additional variations. A high resolution pH 3.5-5.0 agarose IEF gel was able to resolve a total of 10 different monkfish pattern variations in a sample of 24 individuals. A model was proposed suggesting the existence of 16 distinct variations in the monkfish sarcoplasmic protein pattern, based on the various combinations of 4 protein bands. In identifying samples of monkfish meat, it is necessary to compare the unknown pattern with the possible variant patterns to effect a reliable identification. On recommendation by the Associate Referee, the method for fish species identification based on polyacrylamide gel isoelectric focusing, 18.A01-18.A04, has been adopted official final action with no restrictions as to the species that may be identified.
Survey for Cadmium, Cobalt, Chromium, Copper, Nickel, Lead, Zinc, Calcium, and Magnesium in Canadian Drinking Water Supplies
Authors: Méranger Jean C , Subramanian Kunnath S , Chalifoux Chantal 
Published: February 2020

Abstract
A second national survey was done to ascertain the levels of Cd, Co, Cr, Cu, Ni, Pb, Zn, Ca, and Mg in Canadian drinking water supplies. Raw, treated, and distributed water samples collected from 71 municipalities across Canada were analyzed both by atomic absorption spectrophotometry using the direct method and by an APDC-MIBK extraction procedure. As in the first national survey, the amounts of trace metals found in the 3 types of water samples were essentially the same. Contamination of the water supplies with these metals except Cu and Zn was minimal during treatment and distribution. For Canadian drinking water, the median and extreme values expressed as ng metal/mL water were: Cd ≤0.02 (≤0.02-0.07), Co ≤2.0 (≤2.0-6.0), Cr ≤2.0 (≤2.0-4.1), Cu ≤10 (≤10-900), Ni ≤2.0 (≤2.0-69.0), Pb ≤1.0 (≤1.0-79.7), and Zn ≤10 (≤10-750). Hardness values as mg CaCO3/L, ranged from 6.7 in St. John’s, Newfoundland, to 328.3 in Portage La Prairie, Manitoba. The median values for the Canadian drinking water supplies were well below the maximum permissible limits set by Health and Welfare Canada and the World Health Organization.
Analysis of Fat-Soluble Vitamins. XXIV. High Performance Liquid Chromatographic Determination of Vitamin D in Vitamin D Resin Containing Powders: Collaborative Study1
Authors: Mulder Frits J , Vries Ellen J De , Borsje Ben ,   Collaborators:, Ameika L , Gillingham P J , Richter E F , Vries E J de 
Published: February 2020

Abstract
Further study of vitamin D methodology solved the discrepancy between the AOAC chemical method, 43.068-43.078, and the HPLC assay for vitamin D3 in resin containing dry powders. The discrepancy is caused by the difference in solubility of the vitamin D3 resin in benzene and in pentane. The method has been modified accordingly, and has been adopted official first action for vitamin D3 resins and vitamin D3 resin containing powders and aqueous dispersions.
Acid Digestion Determination of Iodine in Foods
Authors: Fischer Peter W F , L’abbé Mary R 
Published: February 2020

Abstract
A method for determining iodine in food is described. The samples were digested using a mixture of sulfuric, nitric, and perchloric acids. The iodine was determined by an automated colorimetric method based on the iodide-catalyzed reduction of Ce+4 by As+3. For milk samples, the relative standard deviation for the method was less than 3%, and the recovery of 125I added to milk and carried through the method ranged from 96 to 102%. The method was compared with 4 other procedures and was superior to alkaline dry ashing methods.
Sodium Hypophosphite as Reducing Agent for Determination of Submicrogram Quantities of Mercury in Animal Feeds and Manures
Authors: El-Ahraf Amer , Willis W Van , Vinjamoori Dutt V 
Published: February 2020

Abstract
The reduction of mercury in samples of dairy cattle and chicken feed rations and manures prepared by acid digestion for determination by flameless atomic absorption is rapidly, smoothly, and quantitatively effected by sodium hypophosphite. The reducing agent is air-stable, is effective over a wide range of mercury concentrations, and is useful in the presence of many mineral acids commonly used for wet digestion of these matrices. The accuracy and precision obtained in determinations with this reagent are equivalent to those obtained using stannous chloride at the same conditions. Recovery efficiencies for the total analytical procedure were studied using cattle manure and feed rations spiked to 0.6 ppm Hg as phenylmercuric nitrate; the range of recoveries varied from 93 to 102% (97% average). The absolute detection limit of the method is 10 ng Hg, and the precision varies in the range of 2.2-6% for samples containing 3 ppt-10 ppm Hg. The advantages of sodium hypophosphite lie in the elimination of premature reduction of mercury caused by traces of stannous chloride adhering to the walls of the reaction vessel, the elimination of several wash steps in the determination, and the long shelf life of the reagent.
Hydrogen Selenide Evolution-Electrothermal Atomic Absorption Method for Determining Nanogram Levels of Total Selenium
Authors: Cox Dennis H , Bibb Ann E 
Published: February 2020

Abstract
A hydrogen selenide (H2Se) evolution-electrothermal atomic absorption method is described for determining nanogram concentrations of total selenium (Se) in biological and environmental materials. A mixed acid digestion procedure is used to decompose organic material. Sodium borohydride, a redesigned hydride generator, and an electric-heated absorption tube are used for H2Se evolution and conversion to atomic Se. The method has a detection limit of 4 ng/mL and a sensitivity of 0.6 ng/mL, and is linear from 0 to 90 ng Se/mL. As determined on urine, water, and bovine liver, total and within-run precision had relative standard deviation values of 5-17.2 and 5.5-12.6%, respectively. Accuracy was established with 2 NBS and 3 EPA reference materials, and mean errors of 0 to +0.8 were obtained. Mean recoveries of 109 and 101% were obtained for 10 and 50 ng Se added to human urine.
Gas-Liquid Chromatographic Detection and Determination of Diacetyl Tartaric Acid Ester of Diglyceride in Dairy and Nondairy Coffee Cream Powders
Authors: Inoue Tetsuo , Iwaida Masahiro , Ito Yoshio , Tonogai Yasuhide 
Published: February 2020

Abstract
Diacetyl tartaric acid ester of diglyceride was directly extracted from dairy or nondairy coffee cream powder under acidic conditions with ethyl acetate; then the extract was saponified with methanolic potash. After acidification with HC1, free fatty acid was removed with ether and the reaction mixture was adsorbed on an anion exchange column. Tartaric acid was eluted with 2N HCl-acetone (1+1). An aliquot of the trimethylsilyl (TMS) derivative of the eluate was injected into a gas chromatograph with flame ionization detection, and a 1.5% SE-30 column. Recoveries of diacetyl tartaric acid ester of diglyceride at 50, 200, and 2000 ppm were 85.6-99.5%.
Extraction of Light Filth from Tea: Collaborative Study
Authors: Lim Faith F ,   Collaborators:, Barnett J , Bright A , Chaput M P , Cox C , Floyd D M , Gentry J , Thrashe J , Washbon E C 
Published: February 2020

Abstract
The present AOAC method for determining insect and rodent filth in tea is time-consuming because it produces filter papers which are heavy in plant residue and therefore requires long paper-reading times. Anew method for the analysis of light filth in tea was developed to remedy existing problems and to improve recoveries. The method consists of the following steps: sample preparation, wet sieving, dilution with 40% isopropanol, extraction with Tween 80-Na4EDTA-40% isopropanol, flotation with mineral oil-heptane, and trapping off in a Wildman trap flask. In an interlaboratory collaborative study, analysts reported combined insect fragment recoveries of 99.2% for the proposed method and 93.0% for the AOAC method; the same analysts recorded combined rodent hair recoveries of 92.2% for the proposed method and 47.6% for the official method. Average times for reading individual subsamples were 9 min for the proposed method and 27 min for the AOAC method. The proposed method has been adopted official first action.
High Pressure Liquid Chromatographic Determination of Antihistamine-Adrenergic Combination Products: Collaborative Study
Authors: Bachman William J ,   Collaborators:, Alpert M Y , Bargo E , Draper R E , Hock W H , Illuminati J , Lookabaugh M , Margosis M , Thompson D W 
Published: February 2020

Abstract
A reverse phase high pressure liquid chromatographic method in which ion-pairing is used for the determination of combinations of pseudoephedrine hydrochloride with triprolidine hydrochloride or chlorpheniramine maleate in syrups and tablets was collaboratively studied by 8 laboratories. Collaborators were supplied with 12 samples including synthetic and commercial syrup formulations and commercial tablet composites. Mean recoveries of pseudoephedrine hydrochloride and triprolidine hydrochloride from synthetic syrup formulations were 100.5 and 99.6%, respectively. Mean recoveries of pseudoephedrine hydrochloride and chlorpheniramine maleate from synthetic syrups were 98.8 and 100.5%, respectively. Mean coefficients of variation for syrups and tablets ranged from 1.68 to 3.07% for pseudoephedrine hydrochloride, from 2.92 to 3.85% for triprolidine hydrochloride, and from 1.34 to 2.15% for chlorpheniramine maleate. The method has been adopted official first action.
Determination of Alkaline Phosphatase in Casein: Collaborative Study
Authors: Murthy Gopala K , Peeler James T ,   Collaborators:, Bone E E , Dickerson B , Johnson W , Maifarth P , Marchetti D , Mullen R , Pyett M M , Riggs T 
Published: February 2020

Abstract
A collaborative study was made to determine alkaline phosphatase in casein samples by the rapid colorimetric test. Six to eight collaborators tested 10 unknown casein samples containing various amounts of residual phosphatase with and without the addition of magnesium acetate. Results indicated that magnesium acetate significantly increased phosphatase activity. The collaborators correctly analyzed 95% of the samples with the added magnesium acetate. The method has been adopted official first action.
Sampling Procedure and Determination of Lead in Canned Foods
Authors: Suddendorf Ronald F , Wright Steven K , Boyer Kenneth W 
Published: February 2020

Abstract
A method is presented for improving within-can homogeneity and simplifying the determination of lead in canned foods. The entire content of a canned food product is blended with 2N HNO3 and allowed to stand 16 h; then the sample is again blended and a subsample is taken. The subsample is digested by wet ashing using nitric acid-perchloric acid or nitric add-sulfuric acid-hydrogen peroxide. The pH of the sample is adjusted with ammonium hydroxide, and the lead is extracted into butyl acetate as the pyrrolidinecarbodithioate complex. Lead concentration is determined by flame atomic absorption spectrometry. Recoveries of lead ranged from 92 to 104% for added 100-mesh lead particulate. Within-sample variability for green beans was reduced from 37% obtained with blending alone to 3.7% using the proposed procedure at the 3.1 μg/g added lead level. Variability was 7.6% at the 0.68 μg/g level and 16.4% at the 0.20 μg/g level of added lead. The use of nitric add-sulfuric acid-hydrogen peroxide for digestion has the advantage of not forming a precipitate during the neutralization step, as occurs when nitric acidpercloric acid is used for dissolution.
Generic Identification of Cooked and Frozen Crabmeat by Thin Layer Polyacrylamide Gel Isoelectric Focusing: Collaborative Study
Authors: Krzynowek Judith , Wiggin Kate ,   Collaborators:, Allsup M G , Annand C , Braddon S A , Carter K , Choromanski J , Haard N F , Kariel N , Laterza A F , Little B W , Lundstrom R C , Martin A M , Morrison R , Odense P , O′leary G P , Pike J , Stiles S , Wittingham L 
Published: February 2020

Abstract
Ten collaborators were required to focus the ureaextracted proteins from 14 crabmeat samples. Six of the samples were knowns and were labeled as to their species. Eight samples were unidentified as to species and were labeled with letters. The 8 unknowns were identified by comparing the focused patterns with the patterns of the 6 species-labeled crabmeat samples. Seventy-nine samples were identified with 97.5% accuracy. This method has been adopted official first action.
Preparation and Characterization of Af latoxin Q1-Hemisuccinate
Authors: Lau H P , Fan S L , Chu F S 
Published: February 2020

Abstract
A method for the preparation and purification of aflatoxin Q1-hemisuccinate is described. The overall yield after final purification was about 80-85% of the starting aflatoxin Q1. The new aflatoxin derivative was characterized by thin layer chromatographic, high performance liquid chromatographic, ultraviolet, mass spectroscopic, and nuclear magnetic resonance spectral analyses.
Molecular Weight Characterization of Food Grade Polyethylenes and Extractables by Size Exclusion Chromatography
Authors: Snyder Roger C , Breder Charles V 
Published: February 2020

Abstract
Size exclusion chromatography (SEC) was used to characterize the molecular weight distribution (MWD) of 6 low density and 6 high density food grade polyethylene resins. The hexane and xylene extractable fractions of these 12 resins were also analyzed by SEC. An IBM 370/168 computer with an APL program was used to analyze the chromatograms and correct for chromatographic band spreading and skewing. Calculated weight average molecular weights (Mw) for the resins ranged from 40 000 to 200 000 and number average molecular weights (Mn) ranged from 6000 to 60 000. Median values of Mw and Mn were 1800 and 950, respectively, for hexane extractables from the low density resins, and were 310 and 290, respectively, for hexane extractables from the high density resins. Corresponding Mw and Mn values for xylene extractables were consistently larger than those for hexane extractables.
Thin layer Chromatographic and Atomic Absorption Spectrophotometric Determination of Methyl Mercury
Authors: Margler Lawrence W , Mah Robert A 
Published: February 2020

Abstract
A method is presented for determining methyl mercury that combines thin layer chromatography and atomic absorption spectrophotometry. The procedure is based on a previously reported method and entails isolating methyl mercury on a thin layer chromatogram, scraping adsorbent into an ignition tube, heating the tube, and moving the mercury vapor under vacuum into an absorption cell where it absorbs light at 253.7 nm. The procedure is sensitive to 0.7 ng Hg. Methyl mercury is extracted from biological samples by distilling, and then extracting with dithizone-chloroform. The extract is concentrated and applied to a thin layer chromatographic plate. The overall sensitivity of the method varies with sample size. For 100 g samples, the method is sensitive to about 9 ng Hg (as methyl mercury)/g (9 ppb).
Distinguishing Common Food-Contaminating Bat Hairs from Certain Feather Barbules
Authors: Olsen Alan R 
Published: February 2020

Abstract
Differences are described between common food-contaminating vespertilionid bat hairs (Chiroptera: Vespertilionidae) and similar-appearing downy feather barbules of passeriform birds, including cuticular scales, pigment distribution, and basal characteristics. Fifteen imported food samples analyzed over a 1½ year period were contaminated with these bat hairs.
Gas-Liquid Chromatographic Determination of Sulfamethazine in Swine and Cattle Tissues
Authors: Manuel Arthur J , Steller William A 
Published: February 2020

Abstract
A gas-liquid chromatographic (GLC) method is described for determining sulfonamide residues in animal tissues, with specificity for 7 sulfonamides. Residues are extracted from tissues with acetonechloroform, fatty substances are removed, and the sulfonamide residue is methylated with diazomethane in acetone-ether to render it amenable to determination by gas-liquid chromatography on an all-glass column suitable for direct on-column injection and a Ni electron-capture detector. Quantitation is achieved by external standardization. The method has a validated limit of sensitivity of 0.10 ppm with the corresponding control values for all tissues being less than 0.01 ppm. Satisfactory recoveries have been obtained for sulfamethazine in swine and cattle tissues. Specificity for sulfamethazine in the presence of sulfathiazole, sulfaquinoxaline, sulfadimethoxine, sulfabromomethazine, sulfaethoxypyridazine, and sulfachloropyrazine is attained by resolution of the respective methyl derivatives on the GLC column.
High Pressure Liquid Chromatographic Determination of Nifursol in Finished Feeds
Authors: George Glenn M , Frahm Larry J , Mcdonnell J Patrick 
Published: February 2020

Abstract
Nifursol is extracted from feed with acetonitrile, and then washed with carbon disulfide to remove feed interferences. An aliquot is concentrated, diluted with 5% NaCl solution, filtered, and then subjected to high pressure liquid chromatography on a strong anion exchange column, using 365 nm photometric detection. The average recovery of nifursol from fortified feed samples was 100.6% with an average coefficient of variation of 3.5%. The nifursol determination is not subject to interference from the other commonly used nitrofurans.
Liquid Chromatographic Method for Determination of Arprinocid in Feed: Collaborative Study
Authors: Fink David W ,   Collaborators:, Andres C N , Brignac P J , Carr K E , Davis E J , Ferder T W , Fin H C , Georg G M , Lawrence A A , Leseney J L , Lowie D , Martin R P , Minyar J P , Pivnichn J V , Quick F , Rowe W D , Shim J -S K , Smallidge R L , Thorp V A , Tola J W , Van Antwer W P 
Published: February 2020

Abstract
An HPLC method for determining arprinocid [9-(2-chloro-6-fluorophenyl)methyl-9H-purin-6-amine] in feed was evaluated in an interlaboratory collaborative study. The samples were prepared in pairs from feeds obtained from 2 commercial feed manufacturers to cover the concentration range 0.0050- 0.0070% arprinocid and were distributed to 14 laboratories. Each collaborator was requested to perform one determination on each of 6 samples. In this analytical procedure, the drug is extracted into CHCI3 and, after appropriate sample preparation by liquid- liquid partitioning, determined using a silica column and ultraviolet detection. The means of the analyses reported by the collaborators ranged from 97 to 104% of the true concentration of arprinocid and were not significantly different (P &gt;0.1) from the true values. The average coefficient of variation was 6.8%. The precision standard deviations of the 3 unit blocks (sr) were each &lt;0.0004% arprinocid, and the F-test demonstrated that systematic error (sb,) did not make a statistically significant contribution (P &gt;0.1) to the standard deviation of the data (sd). This method has been adopted official first action.
Analytical Methodology for Sample Preparation, Detection, Quantitation, and Confirmation of N-Nitrosamines in Foods
Authors: Hotchkiss Joseph H 
Published: February 2020

Abstract
Significant advances have been made over the past decade in methodology for the analysis of foods and other samples for volatile N-nitrosamines. Procedures for the isolation, cleanup, and concentration of N-nitrosamines were developed and applied to a broad range of food types. Several chromatographic techniques and systems have also been developed which are capable of resolving AT-nitrosamines in complex mixtures in a single run, and the use of highly selective detectors has decreased sample preparation time while increasing sensitivity and precision. Unequivocal confirmation of N-nitrosamines in foods can now be achieved by mass spectrometry at low to sub-μg/kg levels. However, further development of methodology for nonvolatile N-nitroso compounds is needed. This review paper discusses these and other topics related to the analysis of foods for N-nitrosamines.
Simultaneous Detection of Several Fusarium Mycotoxins in Cereals, Grains, and Foodstuffs
Authors: Kamimura Hisashi , Nishijima Motohiro , Yasuda Kazuo , Saito Kazuo , Ibe Akihiro , Nagayama Toshihiro , Ushiyama Hirofumi , Naoi Yasuta 
Published: February 2020

Abstract
A systematic method is described for the simultaneous determination of Fusarium mycotoxins (nivalenol, deoxynivalenol, fusarenon-x, diacetoxyscirpenol, neosolaniol, T-2 toxin, HT-2 toxin, butenolide, moniliformin, and zearalenone) in cereals, grains, and foodstuffs. Mycotoxins were extracted with aqueous methanol and purified by a 2-step chromatographic procedure using Amberlite XAD-4 and Florisil columns. The column eluates were concentrated and spotted on a thin layer chromatographic (TLC) plate which was then developed in CHCL3-methanol (93 + 7) and toluene-acetonemethanol (5 + 3 + 2). Each mycotoxin was quantitated by gas chromatography (GO and TLC densitometry. The minimum detectable concentrations (μg/kg) in various test materials were: nivalenol, deoxynivalenol, and fusarenon-x, 2.0; diacetoxyscirpenol, neosolaniol, T-2 toxin, and HT-2 toxin, 80; zearalenone, 10; butenolide, 30; and moniliformin, 50. Recoveries of the mycotoxins added to various cereal samples at 1.0-2.0 Mg/g were greater than 71% and averaged 85%.
High Performance Liquid Chromatographic Determination of Aflatoxicol in Milk, Blood, and Liver
Authors: Trucksess Mary W , Stoloff Leonard 
Published: February 2020

Abstract
Samples of milk were extracted with chloroform, the extract was transferred to methanol, and residual interferences were removed by liquid-liquid partition against hexane and by silica gel column chromatography. Aflatoxicol (AFL) in the purified extract was resolved on a μBondapak C18 column, using water - methanol - acetonitrile - tetrahydrofuran (70 + 15 + 20 + 3) as the mobile phase, and measured with a fluorescence detector (excitation 325-385 nm, emission &gt;408 nm). Recoveries of AFL added to samples of whole pasteurized milk at levels ranging from 0.025 to 0.10 ng/mL averaged 92% (range 78- 100%). The method for AFL has also been applied to the analysis of raw milk, whole beef blood, and beef liver, with recoveries of 70-88%.
Potentiometric and Atomic Absorption Spectrometric Determination of Sulfonamides in Pharmaceutical Preparations
Authors: Hassan Saad S M , Eldesouki Mohamed H 
Published: February 2020

Abstract
Potentiometric and atomic absorption spectrometric (AAS) methods are described for the determination of various sulfonamides in tablets, suspensions, and injections, based on reactions with silver and copper ions. The methods involve direct titration at pH 8, using either a graphite electrode in which silver and copper sulfides have been precipitated, or ion selective electrodes to monitor the potential change. AAS measurements of the excess metal ions after metalsulfonamide reaction are also reported. Results compare favorably with those obtained using USP XIX procedures. The methods described are selective, simple, and precise.