bluuebunny/crossref_metadata_2025_split huggingface dataset:
High Performance Liquid Chromatographic Determination of Intermediates and Reaction By-Products in FD&C Yellow No. 5: Collaborative Study
Authors: Cox Elizabeth A , Mcclure Foster D ,   Collaborators:, Bell S , Beswick R , Bischof R , Gasper G , Gibson L , Goldberg A , Gosselè J , Gunn M , King J , Penta F , Richfield-Fratz N , Shah D , Sutherland A , Young R 
Published: February 2020

Abstract
Eight laboratories participated in a collaborative study of an ion exchange high performance liquid chromatographic procedure for determining the intermediates and 2 reaction by-products in FD&C Yellow No. 5: phenylhydrazine-p-sulfonic acid (PHSA), sulfanilic acid (SA), l-(4-sulfophenyl)-3- carboxy-5-hydroxypyrazolone (PyT), l-(4-sulfophenyl) - 3 -ethylcarboxy-5-hydroxypyrazolone (EEpyT), and 4,4'-(diazoamino)-dibenzenesulfonic acid (DAADBSA). The repeatability and reproducibility standard deviations (absolute) found in the study were 0.0134 and 0.0263 for PHSA at the 0.1% level, 0.0246 and 0.0256 for SA at the 0.2% level, 0.0124 and 0.0149 for EEpyT at the 0.1% level, 0.0212 and 0.0258 for PyT at the 0.2% level, and 0.0234 and 0.0373 for DAADBSA at the 0.2% level. The method was adopted official first action.
Innovations in Atomic Absorption Spectrophotometry with Electrothermal Atomization for Determining Lead in Foods
Authors: Rains Theodore C , Rush Theresa A , Butler Therese A 
Published: February 2020

Abstract
A simple and rapid method is described for the determination of lead in foods. The samples are digested in HNO3, HF, and HCIO4 and then the lead is determined by atomic absorption spectrophometry using an electrothermal atomizer with the L'vov platform. Interferences and ways to improve the precision and accuracy of the analysis were studied. Matrix modification using 1% ammonium phosphate alleviated most interferences encountered. The precision and accuracy of the method was evaluated using NBS SRM 1570 Spinach and SRM 1566 Oyster Tissue. The values obtained are in good agreement with the certified values.
Differential Pulse Polarographic Determination of Iodine in Thyroid Tablets: Collaborative Study
Authors: Holak Walter ,   Collaborators:, Baetz R , Beavin P , Gable P , Hebert R , Illuminati J , Jennings J , Panaro K , Poplawski T 
Published: February 2020

Abstract
A differential pulse polarographic (DPP) method for the determination of iodine in thyroid and thyroid preparations was collaboratively studied by 8 laboratories. The overall concentration of iodine in commercial thyroid tablets containing ¼, 1,2, and 5 gr. of declared thyroid was 0.196%. The overall repeatability and reproducibility standard deviations were 0.0043 and 0.0067, respectively, and the corresponding coefficients of variation were 2.18 and 3.41%, respectively. The results obtained by the DPP method agreed with those obtained by the U.S. Pharmacopeia XX method at the various concentrations of declared thyroid studied. The DPP method has been adopted official first action.
Manual Salicylate-Hypochlorite Procedure for Determination of Ammonia in Kjeldahl Digests
Authors: Fukumoto Helen E , Chang George W 
Published: February 2020

Abstract
The determination of nitrogen in Kjeldahl digests of urine and feces has been simplified by using a manual spectrophotometric method with salicylate and hypochlorite. It neither involves the hazards of the phenol-hypochlorite method, nor requires an automated analyzer. We determined the conditions which minimize the need for precise timing and neutralization of acidic digests and obtained coefficients of variation of about 0.8%. Agreement between the spectrophotometric method and the conventional micro-Kjeldahl method was excellent; a correlation coefficient of 0.9992 and a coefficient of variation of the estimate of 2.1% were obtained. This method is well suited for a laboratory with a moderate volume of samples. We could process at least 200 digests per day, in contrast with the 60 per day which we had previously done by the Kjeldahl distillation and titration.
Defatting Technique for Two Ground Spices Using Simple Reflux Apparatus: Collaborative Study
Authors: Dent Russell G ,   Collaborators:, Bradicich R B , Dzidowski G , Glaze L , Quaife J 
Published: February 2020

Abstract
A solvent defatting technique was tested for 2 spices which require the same extraction process but different defatting agents. For turmeric, which uses isopropanol as the defatting agent, recoveries of rodent hair and insect fragments were not significantly different from those in the original collaborative study, and this technique is recommended as an alternative to AOAC method 44.122(a). However, for oregano, which uses chloroform as the defatting agent, recoveries of insect fragments were significantly lower by the reflux method. An alternative chloroform pretreatment for oregano, therefore, is not recommended for AOAC 44.122(b). It is suggested that reflux action defatting techniques be considered during the developmental stages of new methods. The technique has been adopted official first action for turmeric.
Gas-Liquid Chromatographic Determination of Fenvalerate Insecticide Residues in Processed Apple Products and By-Products
Authors: Spittler Terry D , Argauer Robert J , Lisk Donald J , Mumma Ralph O , Winnett George ,   Collaborators:, Bogus E , Greco E , Gutenmann W , Marafioti R , Miles E , Wszolek P , Zimmerman L 
Published: February 2020

Abstract
Apples from trees treated in the field at 2-week intervals (9 foliar applications) with the synthetic pyrethroid insecticide fenvalerate (cyano(3-phenoxyphenyL)methyl 4-chloro-alpha-(1-methylethyl)- benzeneacetate) were processed into apple sauce, juice, pomace, and peels plus cores. Gas-liquid chromatographic analysis of the commodities for fenvalerate showed the sauce and juice to be essentially residue-free, the whole apples to contain about 0.4 ppm, and the pomace and peels plus cores to contain about 2 and 1.5 ppm, respectively. Agreement among 5 laboratories using modifications of the same basic method was good.
Recovery of Endogenous Selenium from Fish Tissues by Open System Dry Ashing
Authors: May Thomas W 
Published: February 2020

Abstract
Quantitative recovery of endogenous selenium from fish tissues following dry ashing techniques has not been confirmed. An open system dry ashing procedure, using oxidative fusion with Mg(NO3)2•6H2O in the presence of MgO, was tested for recovery of selenium from National Bureau of Standards (NBS) Reference Materials (tuna and oyster) and selected fish tissues. Recovery after dry ashing and hydride analysis was complete from NBS Bovine Liver, Tuna, and Oyster Tissues, as well as from Food and Drug Administration cod, haddock, perch, and flounder research materials. Endogenous selenium, injected into rainbow trout (Salmo gairdneri) as 75Se, was recovered after ashing from liver, ovaries, gastrointestinal tract, muscle, bile, and carcass, 3 and 10 days post-injection. Results indicate that open vessel oxidative fusion is a rapid, simple technique applicable to quantitative recovery of selenium from organoselenium compounds that exist in various aquatic species. The diluted digestate is readily amenable to conventional hydride generation analysis.
Evaluation of Agreement Among Routine Methods for Determination of Fluoride in Vegetation: Interlaboratory Collaborative Study
Authors: Jacobson Jay S , Troiano John J , Cosentini Christina C , Evans John 
Published: February 2020

Abstract
An interlaboratory collaborative study was conducted to evaluate the performance of methods and laboratories for the measurement of fluoride in vegetation. Samples of 8 plant species containing about 5-200 ppm fluoride were distributed to 40 participants who were instructed to use their routine methods of analysis. Methods which had sufficient participants to allow the inclusion of results in statistical analyses were classified into 3 categories: (1) Willard-Winter method (similar to the AOAC official final action method); (2) semiautomated and potentiometric methods (similar to the 2 AOAC official first action methods); and (3) potentiometric analysis with prior ashing, fusion, and/or distillation (not an approved method). There was a significant interaction of methods with samples caused by 3 of the 8 samples. In the other 5 samples, the Willard-Winter and semiautomated methods gave higher mean values for fluoride content than did the 2 potentiometric methods. Despite considerable improvement in speed and simplicity of fluoride analyses during the last decade, agreement between laboratories has not improved because of the variety of methods and techniques in use, the inherent differences between methods, and, apparently, poor laboratory quality control.
Bacillus stearothermophilus Disc Assay for Detection of Inhibitors in Milk: Collaborative Study
Authors: Messer James W , Leslie James E , Houghtby Gary A , Peeler James T , Barnett Jerald E ,   Collaborators:, Appelt A , Boone E , Bryant H , Burroughs L , Coleman K , Cupery M , Cyr R , Dombrowski P , Donahue P , Farmer S , Ginn R , Grant H , Hawkins J , Heady J , Herbst D , Kelley W , Misup M , Morris L , Mullen R , Ondrus N , Payton C , Seiz D , Share R , Stern M , Williams R 
Published: February 2020

Abstract
A 2-part (A and B) collaborative study was conducted on a Bacillus stearothermophilus paper disc (12.7 mm) method to detect residual inhibitors in milk. The 18 participating collaborators assayed raw milk samples spiked with a beta-lactam (penicillin G). Of the 18 collaborators, 14 participated in part A and 16 in part B. Part A demonstrated that either Antibiotic Medium No. 4 or PM Indicator Agar is suitable for use in the assay. The lowest concentration detectable, not significantly different from 100% at the α = 0.05 level, was 0.008 unit/mL with either medium. Part B demonstrated that the sensitivity of the method is equal to that of the current AOAC method (16.131- 16.136). The concentration of beta-lactam detected by 50% of the analysts was 0.003-0.005 unit/mL in this study, compared with 0.005 unit/mL reported in an earlier collaborative study on the current AOAC method. No false positive results were reported in part A or part B. All samples found positive by the confirmatory test in part B were correctly identified as a beta-lactam with commercial Penase discs. The lowest concentration detectable by the method, not significantly different from 100% at the α = 0.05 level, was 0.008 unit/mL. The method was adopted official first action.
Enzymatic Determination of Cholesterol in Egg Yolk
Authors: Shen Chih-Shang J , Chen Isabel S , Sheppard Alan J 
Published: February 2020

Abstract
The quantitative determination of cholesterol in egg yolk by using an enzymatic test kit is described. Cholesterol in the egg yolk is extracted with other lipid components by methylene chloride-methanol (2 + 1) and is enzymatically determined after saponification of the lipid extract. The method is relatively rapid, simple, and accurate and gives results which agree with those obtained by using a gas-liquid chromatographic (GLC) method. The mean cholesterol content of egg yolk determined by the enzymatic and GLC methods was 1237 and 1240 mg/100 g, respectively.
Analysis of Fat-Soluble Vitamins. XXVI. High Performance Liquid Chromatographic Determination of Vitamin D in Fortified Milk and Milkpowder
Authors: Borsje Ben , De Vries Ellen J , Zeeman Jakob , Mulder Frits J 
Published: February 2020

Abstract
Vitamin D is determined by high performance liquid chromatography (HPLC) in samples containing other fat-soluble vitamins. The vitamin D in the unsaponifiable residue is extracted and separated from interferences by straight phase chromatography, and the fraction corresponding to vitamin D3 is collected and quantitated using the AOAC official final action HPLC method for vitamin D3. Analysis of a synthetic mixture gave reasonable recoveries. The method measures potential vitamin D3 content in milkpowder samples containing 2IU vitamin D/g in the presence of all known vitamin D3 isomers, vitamin A, and vitamin E.
A Distributed Processing Laboratory Data System
Authors: Birkel Thomas J , Dusold Laurence R 
Published: February 2020

Abstract
Distributed data processing has been accomplished by a computer system in which laboratory instrument data are collected on a PEAK-11 system for preliminary processing and generation of initial reports. When further processing is required, or when archival storage of raw or processed data is desired, data are transferred over telephone lines to an IBM 3033; an IBM 7406 Device Coupler is used to handle protocol conversion and ″handshaking.″ User-written programs in APL.SV on the IBM machine and in Assembly Language on the PEAK-11 system effect the transfer of bidirectional data. The distributed processing approach allows efficient use of expensive peripherals while maintaining short response times.
Investigations on Nonsulfonamide Bratton-Marshall-Positive Compounds in Porcine Liver
Authors: Parks Owen W , Kimoto Walter I 
Published: February 2020

Abstract
An unknown Bratton-Marshall-positive compound was observed when liver extracts were screened by a procedure for the simultaneous determination of sulfamethazine and sulfathiazole in swine livers. The unknown has been conclusively identified as o-aminobenzoic acid (anthranilic acid), a tryptophan metabolite, by gas-liquid chromatography-mass spectrometry of swine liver extracts obtained by a modified Tishler procedure for sulfonamide residues in animal tissues.
High Pressure Liquid Chromatographic Determination of Sulfamethazine in Pork Tissue
Authors: Cox Byron L , Krzeminski Leo F 
Published: February 2020

Abstract
A high pressure liquid chromatographic (HPLC) method has been developed for determination of sulfamethazine residues in pork liver, kidney, muscle, and fat. The sample was extracted with acetone- chloroform, concentrated in the presence of dilute HC1, and partitioned between dilute HC1 and hexane. The acid solution was washed with methylene chloride and then buffered with trisodium citrate and sodium hydroxide to pH 5.8-5.9. Sulfamethazine was extracted from the aqueous mixture with methylene chloride, concentrated, dissolved in buffer, and eluted from XAD-2 resin with methanol. Sulfamethazine was reliably quantitated at 0.1 ppm by HPLC on a Zorbax ODS column with detection at 254 nm with no interference from tissues or reagents. The average recovery from the edible tissues, i.e., liver, muscle, kidney, and fat, fortified at 0.1-0.4 ppm was 85.6 ± 3.7%.
Mineral Oil Vacuum Distillation Method for Nitrosamines in Fried Bacon, with Thermal Energy Analyzer: Collaborative Study
Authors: Greenfield Earl L , Smith Wertice J , Malanoski Anthony J ,   Collaborators:, Benson M , Fiddler W , Grabber M , Herring H , Hill K , Legette L , Meyer K A , Robach M , Wolfe M 
Published: February 2020

Abstract
Nine laboratories participated in a collaborative study of a method for determining 6 nitrosamines, dimethylnitrosamine, diethylnitrosamine, dibutylnitrosamine, nitrosopiperidine, nitrosopyrrolidine, and nitrosomorpholine, in the 5-17 ppb range. The coefficients of variation for repeatability were 10.8, 8.5,10.4, 8.5, 8.7, and 7.8% with corresponding coefficients of variation for reproducibility of 16.4, 12.0,13.6,10.8,11.2, and 10.3% and recoveries of 89.6, 91.6, 84.7, 90.0, 89.6, and 88.1%, respectively. The method was adopted official first action.
High Performance Liquid Chromatographic Determination of Minor Saccharides in Corn Sugar: Collaborative Study
Authors: Engel C Earl , Olinger Philip M , Bernetti Raffaele ,   Collaborators:, Brobst K M , Holme R A , Lodge R E 
Published: February 2020

Abstract
The official first action AOAC method for quantitative determination of saccharides in corn syrup by liquid chromatography was reinvestigated to expand its scope to products containing dextrose in excess of 98%. Because of the low levels of saccharides other than dextrose (DP1), separations are carried out only of the DP1, the disaccharides (DP2), and the tri- and higher saccharides (DP3+) on an Aminex Q15-S, calcium form, cation exchange column. Concentrations of solids in water solvent injected into the liquid chromatograph are higher than those in the AOAC method to increase precision of analysis of the minor saccharides. All carbohydrate components in solution are eluted from the column; therefore, loss of refractive index detector linearity with respect to dextrose is compensated by use of an external maltose (DP2) standard to correct for DP2 and DP3+ response and dextrose is calculated by difference from 100. With mean values of 0.520% DP2 and 0.244% DP3+, the reproducibility and repeatability coefficients of variation are 14.6 and 6.7% for DP2, and 19.3 and 11.9% for DP3+, respectively. Dextrose levels of 99.23% are reproducible within 0.161. The coefficients of variation of the DP2 component are lower by this method than by the AOAC method at levels up to 2% DP2. The method has been adopted official first action.
AC Polarographic Determination of Cloxacillin
Authors: Nunez-Vergara Luis J , Silva Marisol M , Squella Juan A 
Published: February 2020

Abstract
Hydrolysis of cloxacillin at pH 4.0 yields an electro-active product which can be determined by polarography. Depending on the concentration of cloxacillin, one of 2 peaks was obtained: The potential ac peaks for a 4.36 mM cloxacillin solution were peak I, –0.23 V and peak II, –0.13 V. For analytical purposes, the first peak was used. A linear relationship was established for levels of cloxacillin between 2.2 × 10–5 and 2.2 × 10–3 M. Average recovery was 98.8% (SD 1.8), indicating satisfactory accuracy for the method. Individual capsule and composite assays as well as interference tests are described.
Quantitative Estimates of Beta-Lactam Residues in Raw Milk Around a Reference Standard: Collaborative Study
Authors: Ginn Roy E , Case Ronald A , Packard Vernal S , Tatini Sita R ,   Collaborators:, Bone E , Brizendine M , Curme A , Danilowier P R , Fuqua R , Grant H H , Heady J , Henrickson H , Kelley W N , Leslie J E , Schneider D E , Williams R R 
Published: February 2020

Abstract
A collaborative study was conducted to determine the reliability of a Bacillus stearothermophilus disc assay method for differentiating various concentrations of penicillin in raw milk. Participating laboratories tested 10 different samples (including one negative) in blind duplicate. Triplicate standards were alternated with triplicate unknowns around the periphery of each of 5 different plates. Zone diameters were measured and the difference in zone size of pairs of adjacent standard and unknown samples were analyzed by a paired t-test. Penicillin concentrations 0.003 IU/mL different from the reference concentrations were consistently distinguishable at a 95% confidence level. Such discriminatory power was determined to be possible with as few as 3 plates (9 replicates) per unknown. The method has been adopted official first action.
Capillary Gas-Liquid Chromatographic Determination of Vomitoxin in Cereal Grains
Authors: Huguette Cohen , Lapointe Michel 
Published: February 2020

Abstract
A gas-liquid chromatographic (GLC) method, using an electron capture detector, is described for determining vomitoxin in cereal grains at levels as low as 0.05 ppm. Samples are extracted with chloroform-ethanol and initially purified by using a Sep-Pak silica cartridge, followed by column chromatography using Sephadex LH-20. Additional purification is achieved by using a disposable cyano cartridge. Heptafluorobutyrylimidazole (HFBI) is added to form esters of the analytes. The HFB esters of vomitoxin are separated on a 30 m × 0.25 mm fused silica column coated with SE-54 and measured with a 63Ni electron capture detector. Samples were confirmed by gas-liquid chromatography/mass spectrometry using electron impact ionization and single ion monitoring at the molecular ion mass of 884.05 and at 10 000 resolving power. The method has been applied to wheat, oats, barley, and corn. The limit of detection is 0.05 ppm vomitoxin. Average recoveries were 89.8% with a coefficient of variation of 4.0%.
Nutritional Adequacy of Commercial Baby Foods
Authors: Yeung D L 
Published: February 2020

Abstract
The nutritional adequacy of commercial baby foods is assessed from data derived from a longitudinal nutrition survey of 400 infants in Canada. On the average, the nutrient intakes from infant food meet or exceed the recommended daily allowances for most nutrients. Most infants would not be able to meet the minimum daily requirements for iron, B vitamins, or calcium if infant cereals were not fortified.
Colorimetric Method for Field-Screening Above-Tolerance Parathion Residues on and in Citrus Fruits
Authors: Ott Daniel E , Gunther Francis A 
Published: February 2020

Abstract
A colorimetric technique has been developed which is suitable for use as a field-screening method for detecting above-tolerance levels of parathion on and in citrus fruits. By using this method, a grower should be able to postpone harvesting a crop until parathion residues are below tolerance level, so that the crop is safe to market. The method depends on the reaction of parathion with 4-(p-nitrobenzyl)- pyridine. Parathion is extracted by mixing chopped citrus rind with acetone in a hand-operated homogenizer. The extract is partially cleaned by a partitioning step before final cleanup with a Sep-Pak Florisil cartridge. The colored reaction solution is read at 560 nm by using a portable, rechargeable spectrophotometer. A single test can be completed in about 75 min; the average time per test when several are conducted sequentially is considerably shorter. The analytical system responds readily to &lt;5 ppm parathion on or in 1 g navel orange rind, which corresponds to &lt;1 ppm in the whole fruit. The present U.S. tolerance for parathion on or in citrus is 1 ppm on a whole fruit basis. Preliminary work indicates that the method should also be suitable for apples.
Automated Extraction Technique for Determination of Experimental Insecticide Nifluridide and Its Cyclized Product in Water by High Pressure Liquid Chromatography
Authors: West Sheldon D , Dorulla Georgia K , Poole George M 
Published: February 2020

Abstract
A method is described for the simultaneous determination of the experimental insecticide nifluridide (N-(2-amino-3-nitro-5-(trifluoromethyl)phenyl)- 2,2,3,3-tetrafluoropropanamide) and its cyclized product, EL-919 (7-nitro-2-(l,l,2,2-tetrafluoroethyl)- 5-(trifluoromethyl)benzimidazole), in water. Both compounds are extracted by passage of up to 500 mL water through two Sep-Pak C18 cartridges joined in series. The extraction is automated by using vacuum. The compounds are eluted from the cartridges with acetonitrile. Both compounds are then separated and measured by high pressure liquid chromatography with UV detection at 235 nm. Recoveries were 91.2-97.1% nifluridide and 82.7-98.0% EL-919 for deionized water samples fortified with 0.001-0.1 ppm nifluridide and 0.005-0.1 ppm EL-919. Analysis of water samples (pH 8) from bluegill and rainbow trout toxicity studies with nifluridide resulted in a half-life determination of 10 h at 13°C and 2.5 h at 20°C with nearly quantitative conversion to EL-919 within 96 h.