bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of Methylene Blue in Channel Catfish {Ictalurus punctatus) Tissue by Liquid Chromatography with Visible Detection
Authors: Turnipseed Sherri B , Roybal José E , Plakas Steven M , Pfenning Allen P , Hurlbut Jeffrey A , Long Austin R 
Published: February 2020

Abstract
Methylene blue (MB) is a thiazine dye that, although not regulated for use with edible fish, may sometimes be used as a chemotherapeutic agent in the aquaculture industry. A liquid chromatographic (LC) method was developed for the determination of MB in fish muscle. MB was extracted from catfish tissue with an acetonitrile-acetate buffer solution containing hydroxylamine and toluene- sulfonic acid, partitioned into methylene chloride, and cleaned up on alumina and carboxylic acid solid-phase extraction cartridges. MB concentrations were determined by LC with visible detection at 660-665 nm. Recoveries of MB from catfish fortified at 10-50 ng/g were 75-90% (RSDs, 5-12%). Leu- comethylene blue also can be recovered from catfish tissue as the MB colored form at low levels with similar recoveries. Analysis of catfish exposed to MB in a bath treatment at 5 ppm MB for 1 h recovered 10-20 ppb of the drug in the muscle tissue. The low tissue concentration suggests poor absorption of this drug compared with other antifungal dyes that tend to concentrate and remain in fish tissue at high levels.
N-Nitrosodibenzylamine in Boneless Hams Processed in Elastic Rubber Nettings
Authors: Fiddler Walter , Pensabene John W , Gates Robert A , Custer Carl , Yoffe Aron , Phillipo Tom 
Published: February 2020

Abstract
Boneless hams processed in elastic rubber nettings contain high levels of nitrosamines in the outermost layer. The precursors of the nitrosamines are zinc dibutyl-or dibenzyldithiocarbamate used as a vulcanizing agent in the formulation of the rubber. The outermost layer from 59 commercial hams was analyzed for 11 volatile nitrosamines including N-nitrosodibutylamine (NDBA) and N-nitrosodibenzylamine (NDBzA). The principal nitrosamine, NDBzA, was detected in 32 (54%) ham samples at the 10-100 ppb range; it exceeded 100 ppb in 18 (30%) samples, with the highest at 512.2 ppb. No nitrosamine was detected in 7 of 59 ham samples. To determine the cause of the high NDBzA values, various types of unused nettings (from different manufacturers) accompanying the samples were analyzed for nitrosamines. No correlation was found between the NDBzA content of the hams and the nettings. The results suggest that the problem of nitrosamine formation in these products has not yet been resolved.
Determination of Total, Saturated, Unsaturated, and Monounsaturated Fats in Cereal Products by Acid Hydrolysis and Capillary Gas Chromatography: Collaborative Study
Authors: Ngeh-Ngwainbi Jerry , Lin James , Chandler Anthony ,   Collaborators:, Bannon C , Carr K , Condra C , Fagerle R , Fein R , Fusnacht J , Graff T , Hussein A , Kanno A , Kraft N , Kraus D , Marcuson D , Mitchell B , Oehrl L , Oles P , Patzer S , Sackett P , Salata S , Buick D , Sinclair A , Wo C , Scheelings P , Sudler M , Sullivan D , Williams A , Zygmunt L 
Published: February 2020

Abstract
Fifteen laboratories participated in a collaborative study to determine total, saturated, unsaturated, and monounsaturated fats in cereal products by gas chromatographic (GC) analysis of fatty acid methyl esters (FAMEs). Cereal products, representing a wide range of cereal grains and processes, were hydrolyxed in 8N HCI and extracted with ethyl and petroleum ethers. FAMEs were produced by the reaction of the mixed ether extracts with sodium hydroxide in methanol (NaOH/MeOH) and then with boron trifluoride reagent (14% BF3 in MeOH). They were quantitatively determined by capillary GC. Total fat was calculated as the sum of individual fatty acids expressed as triglyceride equivalents in accordance with nutrition labeling guidelines. Saturated, unsaturated, and monounsaturated fats were calculated as sums of individual fatty acids. The total fat contents of samples ranged from 0.56 to 12.64%. A split design was used to determine performance parameters of results obtained by 15 laboratories on 24 samples. Of the 24 samples, 7 were blind duplicates and 5 were independent materials. Statistical analysis for total fat yielded a relative standard deviation for repeatability (RSDr) range of 1.32 to 13.30% and a relative standard deviation for reproducibility (RSDr) range of 4.42 to 22.82%. The goal of this study was to determine total fat, saturated fat, unsaturated, and monounsaturated fat in cereal-based products by complete extraction, methylation, and quantitation of total fatty acids. The acid hydrolysis-capillary GC method for determining total, saturated, unsaturated, and monosaturated fats in cereal products has been adopted by AOAC INTERNATIONAL.
Determination of Dislodgeable Residues of N-4-Chlorobenzoyl-N’-Benzoyl-N’-tert-Butylhydrazine (RH-0345) from Grass by Liquid Chromatography
Authors: Skorczynskis Stephen S 
Published: February 2020

Abstract
A simple method for determining chemically and physically dislodgeable residues of N-4-chloroben-zoyl-N′-benzoyl- N′-tert-butylhydrazine (RH-0345) from grass is described. To determine chemical dis- lodgeability, a sample of fresh grass leaves is washed with deionized water containing a small amount of the wetting agent Aerosol OT-75. Quantitation of residues removed from the grass is based on the total surface area of grass analyzed. Physical dislodgeability is measured by sampling an area of turf for 1 min. Sampling is accomplished by a person wearing a dosimeter made from a common athletic sock. Grass-stained socks are extracted with 75% acetonitrile in deionized water, and the extracts are diluted with water. Quantitation of physically dislodgeable residues is based on the total RH-0345 residue adsorbed on the sock and is expressed as ng RH-0345/cm2 of sock in contact with the grass. For amounts of dislodgeable residues greater than the threshold value of 250 ng/cm2 for grass and 100 ng/cm2 for socks, extracts are analyzed directly by liquid chromatography (LC) using a C8 column and UV detection at 260 nm. For samples with significantly lower amounts of dislodgeable residues, diluted extracts are partitioned with methylene chloride. The methylene chloride containing the RH-0345 residues is evaporated just to dryness, and the residues are reconstituted in 30% acetonitrile in water and then analyzed by LC. The validated sensitivity of the method is 0.5 ng/cm2 for grass and 50 ng/cm2 for cotton socks. Grass was fortified at 0.5–10 000 ng/cm2. Average RH-0345 recovery from grass was 94 ± 10% standard deviation (SD). Apparent RH-0345 residues in control grass were 0.0558 ng/cm2. Socks were fortified at 50–40 000 ng/cm2. Average RH-0345 recovery from socks was 98 ± 7% SD. Apparent RH-0345 residues in control socks were 6.13 ng/cm2.
Liquid Chromatographic Determination of Glyphosate in Water-Soluble Granular Formulations: Collaborative Study
Authors: Morlier Lynn W , Tomkins David F ,   Collaborators:, Koppen B , Declercq B , Weller O , Gregoric A , Focht C , Roberts G , Harbin D , Schreuder R H , Hicks H , Verbist F , Wieland T , Bjorholm T , Manso L , Cohen S , Lee E , Zurcher T , Muller M D , Tomkins D F , Noble A , Schlesinger H D , Smallage B , Tarn K C , Kim Y-W , Sato T , Schultz D I , Parsons A , Galoux I M , Hussain M , Masollerx F M E 
Published: February 2020

Abstract
A liquid chromatographic (LC) method for the determination of glyphosate in various water-soluble granular formulations was tested by 28 laboratories. Samples were dissolved in mobile phase and injected directly into an LC system with a 25 cm SAX column and a mobile phase of 96% aqueous buffer solution, 0.0062M KH2PO4, and 4% methanol. Detection was by UV absorption at 195 nm. Manual or automated injections were made via fixed-volume loops. Calculations were based on peak area comparisons with external standards. The collaborative study analyzed 5 matched pairs of 4 water-soluble granular formulations, with one determination per sample. The study generated 138 matched pairs, which were analyzed by using the AOAC spreadsheet and Youden’s matched-pair calculations. Coefficients of variation for the 4 formulations ranged from 0.65 to 1.37%. The LC method for the determination of glyphosate in water-soluble granular formulations has been adopted first action by AOAC INTERNATIONAL.
Liquid Chromatographic Determination of Acriflavine and Proflavine Residues in Channel Catfish Muscle
Authors: Plakas Steven M , El Said Kathleen R , Jester Edward L E , Bencsath F Aladar , Hayton William L 
Published: February 2020

Abstract
A liquid chromatographic (LC) method was developed for determination of acriflavine (ACR) and proflavine (PRO) residues in channel catfish muscle. Residues were extracted with acidified methanol solution, and extracts were cleaned up with Ci& solid-phase extraction columns. Residue concentrations were determined on an LC cyano column, with spectrophotometric detection at 454 nm. Catfish muscle was individually fortified with ACR (purified from commercial product) and PRO at concentrations of 5,10,20, 40, and 80 ppb (5 replicates per level). Mean recoveries from fortified muscle at each level ranged from 86 to 95%, with relative standard deviations (RSDs) of 2.5 to 5.7%. The method was applied to incurred residues of ACR and PRO in muscle after waterborne exposure of channel catfish to commercial acriflavine (10 ppm total dye for 4 h). RSDs for incurred residues of ACR and PRO were in the same range as those for fortified muscle. Low residue concentrations (&lt;1 % of exposure water concentration) suggested poor absorption of ACR and PRO in catfish.
VIDAS Enzyme-Linked Fluorescent Immunoassay for Detection of Salmonella in Foods: Collaborative Study
Authors: Curiale Michael S , Gangar Vidhya , Gravens Carol ,   Collaborators:, Agin J R , Bound A , Bowles L , Brockman R , Brusatti L , Bulawka C E , Cohen A , Deeks C , Eklund C A , Fukuoka J , Gangar V , Hammer C , Harris L , Hoffman C , Jost-Keating K , Keng J G , Kerdahi K , Krzyanowski W , Manley D , Miller C , Mondon D , Neufang K , Niroomand F , Plante R , Post L , Roman M , Rude D , Raghubeer E V , Ryder J , Smith C , Stoltzner L , Thomas L , Vanderbilt B , Wright T 
Published: February 2020

Abstract
The VIDAS SLM method for detection of Salmonella was compared with the Bacteriological Analytical Manual (BAM)/AOAC culture method in a collaborative study. Twenty laboratories participated in the evaluation. Each laboratory tested one or more of 6 test products: milk chocolate, nonfat dry milk, dried whole egg, soy flour, ground black pepper, and ground raw turkey. No significant differences (P&lt; 0.05) were observed between the 2 methods. The 2 methods were in agreement for 99% of 1544 samples analyzed. Of the 20 samples out of agreement, 8 were VIDAS SLM positive and BAM/AOAC negative, and 12 were VIDAS SLM negative and BAM/AOAC positive. The VIDAS SLM method for detection of Salmonella in foods has been adopted first action by AOAC INTERNATIONAL.
High-Sensitivity Dry Rehydratable Film Method for Enumeration of Coliforms in Dairy Products: Collaborative Study
Authors: Curiale Michael S , Gangar Vidhya , D’onorio Armando , Gambrel-Lenarz Sonya , Mcallister J Sue ,   Collaborators:, Bailey B , Bednar A M , Bowen B , Brown D , Bulthaus M , Cash J , Cirigliano M , Cox M , D’onorio A , David O E , Fraser J , Frye K , Gangar V , Gambrel-Lenarz S , Hanlin J , Helbig T , Johnson J , Jost-Keating K , Kora L , Koeritzer R , Kozlowski S , Kraemer M , Lally S , Lambeth B , Lawlor K , Lewandowski V , Lopez S , McDonald S , Mclntyre S , Naq M , Pierson M , Reinhard J , Richter D , Saunders L , Simpson P , Smoot L , Tong M S , Warburton D , Williams H , Wilson-Perry A , Yuan J 
Published: February 2020

Abstract
A dry-film coliform count plate that is inoculated with 5 mL sample was compared with the Violet Red Bile Agar plate method in a collaborative study by 18 laboratories. Products analyzed were 2% milk, chocolate milk, cream, vanilla ice cream, cottage cheese, and cheese. Collaborators tested blind duplicate uninoculated samples and samples inoculated at low, medium, and high level. Significantly (P&lt; 0.05) higher numbers of coliforms were recovered by the dry-film method from 2% milk samples at the 3 inoculum levels, the chocolate milk at the low- and high-inoculum levels, and the cream at the high-inoculum level. Significantly higher counts were obtained by the agar method for cottage cheese samples at the low-inoculum level. The repeatability standard deviation for the dry-film method was significantly higher for the high-inoculum level chocolate milk sample and the medium-inoculum level cottage cheese. The same statistic was significantly higher for the agar method at all 3 inoculum levels in the 2% milk and the medium-inoculum level cream. The high-sensitivity dry rehydratable film method for enumeration of coliforms in dairy products has been adopted first action by AOAC INTERNATIONAL.
Visual Immunoprecipitate Assay (VIP) for Detection of Enterohemorrhagic Escherichia coli (EHEC) 0157:H7 in Selected Foods: Collaborative Study
Authors: Feldsine Philip T , Albo-Nelson Maria T , Brunelle Sharon L , Forgey Robin L ,   Collaborators:, Al-Hasani S , Ball C , Beatty S , Blanchfield B , Bowen B , Bremer N , Brookman D , Brookman S , Brushaber M , Bryant J , Bryant D , Bryant R , Chlebowski E T , Copeland F , Culak D A , Dalley E , Destro C , Finkenbiner D , Frissora R , Fung D Y C , Garcia G R , Gray M R , Hagen C J , Harshavardhan T , Hart-Thakur R , Inami G , Johnson S , Kandakai L V , Lessard D , Lin S , Liu V , Matiuck S , McAteer L , Miller L , Moon B , Nasri H , Pack L , Pilot K , Price C , Pruett P , Ramirez C , Richter D , Schmieg J A , Schultz G , Sloan E M , Sprague D M , Tebay D , Tomer J , Tuncan E , Warburton D , Watson M , West D 
Published: February 2020

Abstract
Five foods representative of a variety of food products were analyzed by the Visual Immunoprecipitate Assay (VIP) and the Bacteriological Analytical Manual (BAM) culture method for the presence of Escherichia coli 0157: H7. A total of 21 laboratories representing state and federal government agencies, as well as private industry, in the United States and Canada participated. Food types were inoculated with strains of E. coli 0157:H7, with the exception of one lot of poultry, which was naturally contaminated. During this study, a total of 1377 samples and controls were analyzed and confirmed, of which 508 were positive and 867 were negative by both methods. Two samples were positive by BAM and negative by VIP. Because of the study design, it was not possible for the BAM method to produce false-negative or false-positive results. The VIP assay for detection of EHEC in selected foods has been adopted first action by AOAC INTERNATIONAL.
Liquid Chromatographic Method for Determination of Vanillin and Ethyl Vanillin in Imitation Vanilla Extract (Modification of AOAC Official Method 990.25): Collaborative Study
Authors: Kahan Sidney , Krueger Dana A ,   Collaborators:, Berger R , Filandro A , Hageman L R , Korpinski T , Lin S , Lally N E , Parrish M , Schoen K L 
Published: February 2020

Abstract
A collaborative study of a method for analysis of vanillin and ethyl vanillin in fortified and imitation vanilla flavors was performed. The method, which is an extension of AOAC Official Method 990.25, Vanillin, Vanillic Acid, p-Hydroxybenzaldehyde, and p-Hydroxybenzoic Acid in Vanilla Extract, Liquid Chromatographic Method, involves reversed-phase high-pressure liquid chromatography (LC) of the sample on a Cβ column with a water-methanol-acetic acid (89 + 10 + 1) mobile phase and UV detection at 254 nm. The method yields good recoveries of vanillin at 484 and 723 mg/100 mL and of ethyl vanillin from 37 to 400 mg/100 mL. For vanillin, repeatability (r) values were 8 mg/100 mL at a level of 155 mg/100 mL, 12 mg/100 mLat a level of 484 mg/100 mL, and 31 mg/100 mL at a level of 723 mg/100 mL. Reproducibility (R) values were 20 mg/100 mL, 55 mg/100 mL, and 137 mg/100 mL over the same range. For ethyl vanillin, r values were 2.4 mg/100 mL at a level of 37 mg/100 mL, 3.2 mg/100 mL at a level of 74 mg/100 mL, and 8.6 mg/100 mL at a level of 180 mg/100 mL. R values were 6.4 mg/100 mL, 5.4 mg/100 mL, and 22.0 mg/100 mL over the same range. AOAC Official Method 990.25 has been modified to include determination of ethyl vanillin in vanilla extract and artificial vanilla flavor.
Determination of ß-Glucan in Barley and Oats by Streamlined Enzymatic Method: Summary of Collaborative Study
Authors: Mccleary Barry V , Mugford David C ,   Collaborators:, Camire M C , Gibson T S , Harrigan K , Janning M , Meuser F , Williams P 
Published: February 2020

Abstract
A collaborative study was conducted involving 8 laboratories (including the authors’ laboratories) to validate the streamlined enzymatic method for determination of ß-D-glucan in barley and oats. In the method, the flour sample is cooked to hydrate and gelatinize ß-glucan, which is subsequently hydrolyzed to soluble fragments with the lichenase enzyme. After volume and pH adjustments and filtration, the solution is treated with ß-glucosidase, which hydrolyzes ß-gluco-oligosaccharides to D-glucose. D-Glucose is measured with glucose oxidase-peroxidase reagent. Other portions of lichenase hydrolysate are treated directly with glucose oxidase-peroxidase reagent to measure free glucose in test sample. If levels of free glucose are high, the sample is extracted first with 80% ethanol. For all samples analyzed, the repeatability relative standard deviation (RSDr) values ranged from 3.1 to 12.3% and the reproducibility relative standard deviation (RSDR) values ranged from 6.6 to 12.3%. The streamlined enzymatic method for determination of ß-D-glucan in barley and oats has been adopted first action by AOAC INTERNATIONAL.
Gas Chromatographic Method for Putrescine and Cadaverine in Canned Tuna and Mahimahi and Fluorometric Method for Histamine (Minor Modification of AOAC Official Method 977.13): Collaborative Study
Authors: Rogers Patricia L , Staruszkiewicz Walter ,   Collaborators:, Adams A , Atienza B , Berg R J , Chin H , DesJardins C , Gilgan M , Hansen L B , Hummer W , Jahncke M , Jester E , Kennedy K , Krzynowek J , McLachlan D , Mowdy D , Newton R T , Personeau J C , Rorberg J A , Shum G , Thomas T S , Wagner R , Whitby C , Yuen G 
Published: February 2020

Abstract
A collaborative study was conducted to test a modification to the AOAC fluorometric method for histamine (AOAC® Official Method 977.13) that substitutes 75% methanol as the extracting solvent. All other steps remain unchanged. The extracts prepared with 75% methanol were also used to collaboratively test a gas chromatographic (GC) method for determination of putrescine and cadaverine in seafood. In the GC method, the extracted diamines are converted to fluorinated derivatives, the reaction mixtures are passed through solid-phase extraction columns, and the derivatives are quantitated by electron capture GC after separation on an OV-225 column. Fourteen laboratories using the GC method for putrescine and cadaverine and 16 laboratories using the fluorometric method for histamine analyzed 14 canned tuna and raw mahimahi (including blind duplicates and a spike) containing 0.2-2.6 ppm putrescine, 0.6-9.1 ppm cadaverine, and 0.6-154 ppm histamine. At the 5 ppm level, recoveries ranged from 71 to 102% for putrescine and 77 to 112% for cadaverine; the respective repeatability relative standard deviations (RSDr) were 5.2 and 15%, and the respective reproducibility relative standard deviations (RSDR) were 8.8 and 18%. At the 50 ppm level, histamine recoveries ranged from 84 to 125%, RSDr was 3.6%, and RSDR was 9.4%. The GC method for determination of putrescine in canned tuna and cadaverine in canned tuna and mahimahi has been adopted first action by AOAC INTERNATIONAL, and the AOAC Official Method 977.13, Histamine in Seafood, Fluorometric Method, has been modified
Study of Pesticide Synthesis Residual Products in Commercial Chlorpyrifos Formulations
Authors: Melgosa Elena Romero , Barrio Cecilia áSaenz , Asensio Jesús Sanz , Bernal Javier Galbán 
Published: February 2020

Abstract
A method to separate and identify manufacturing residual products (MRPs) in commercial formulations of chlorpyrifos is presented. The method is based on 3 stages: (1) qualitative study by capillary gas chromatography, (2) separation by liquid chromatography, and (3) identification by mass spectrometry and nuclear magnetic resonance spectroscopy. Using this methodology, the authors identified different MRPs in commercial chlorpyrifos: a phosphorochloridothioic acid O,O-diethyl ester chloride, TCP (3,5,6-trichloropyridin-2-ol), and sulfotep (tetraethyl dithionopyrophosphate). In addition, a compound that has not been described until now, was identified. Given the name “Romerales,” the compound has toxicity similar to or greater than that of chlorpyrifos.
Planar Chromatographic and Liquid Chromatographic Analysis of Thiamphenicol in Bovine and Human Plasma
Authors: Dreassi Elena , Corbini Gianfranco , Ginanneschi Vittoria , Corti Piero , Furlanetto Sandra 
Published: February 2020

Abstract
A planar chromatographic (PC) method was developed to determine thiamphenicol in human and bovine plasma with florphenicol as internal standard. The performance of the method was compared with that of a liquid chromatographic method. Recovery of extraction method developed for plasma was 81.51 ± 2.85%. Reproducibilities of the PC assay performed with various PC plates were also good.
Liquid Chromatographic Determination of Thalidomide in Tablets, Capsules, and Raw Materials
Authors: Reepmeyer John C , Cox Don C 
Published: February 2020

Abstract
A simple, isocratic liquid chromatographic method for assay of thalidomide in tablets, capsules, and raw materials was developed. The method uses a Nova-Pak octadecylsilane bonded-phase column (150 × 3.9 mm, 4 μm particle size), a mobile phase of acetonitrile-water (15 + 85), a flow rate of 1 mL/min, detection at 237 nm, and phenacetin as internal standard. Phosphoric acid was used in preparation of sample solutions to inhibit thalidomide hydrolysis. Assays ranged from 99.3 to 100.4% in raw materials from 4 manufacturers, from 79.7 to 104.8% in tablets from 7 manufacturers, and from 75.3 to 102.6% in capsules from 4 manufacturers. Assay method precisions for triplicate analyses on 5 days were 0.30% for tablets, 0.22% for capsules, and 0.22% for raw materials. Recovery from simulated tablet formulations was 100%. The method has been used to analyze individual tablets and capsules for determination of content uniformity.
Determination of Sodium in Biological Materials by Instrumental Neutron Activation Analysis
Authors: Cunningham William C , Capar Stephen G , Anderson David L 
Published: February 2020

Abstract
A formalized method for determining sodium in biological materials by instrumental neutron activation analysis is presented. The method includes common procedures from the numerous options available to this historically nonformalized analytical technique. The number of procedural options is restricted to minimize the method’s complexity, yet the method is still applicable to a variety of neutron activation facilities. High accuracy and precision are achieved by placing bounds on allowed uncertainty at critical stages of the analysis. Analytical results from the U.S. Food and Drug Administration laboratory and 4 other laboratories demonstrate the method’s performance.