bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rapid, Economical Method for Determination of Aflatoxin and Ochratoxin in Animal Feedstuffs
Authors: Roberts Basil A , Glancy Edward M , Patterson Deryck S P 
Published: February 2020

Abstract
A quantitative procedure widely used in European Economic Community (EEC) countries has been successfully scaled down to produce a rapid method for determination of af latoxin B1 (and other anatoxins) in animal feeds. Without modification, the method may be used for simultaneous ochratoxin A determination in simple feeds, but a slightly different extraction procedure is required for compound feeds. Validity of the method has been demonstrated by comparison with the full EEC procedure for aflatoxin B1 and the Nesheim method for ochratoxin A. Analyses may be completed within 2 h and there is a considerable savings in materials over the 2 reference methods. The procedure is also less hazardous because volumes of toxic extract are small, and the operator is exposed to minimum solvent vapor.
Determination of Aflatoxins in Animal Tissues
Authors: Stubblefield Robert D , Shotwell Odette L 
Published: February 2020

Abstract
A method for the determination of aflatoxins in animal tissues has been developed, and applied successfully to beef, swine, chicken, and human livers, and to beef kidney, heart, spleen, muscle, and blood. Blended tissue is denatured with citric acid and extracted with dichloromethane on a wrist-action shaker. After filtration, the extract is partially purified on a silica gel column, and aflatoxins B1 and M1 are determined by 2-dimensional thin layer chromatography and densitometry. Recoveries of Bi and Mi added to meat tissues and blood were approximately 90 and 80%, respectively. The method gave results for a contaminated freeze-dried liver comparable to analyses by 3 other published meat tissue methods. The method is rapid and has a determination limit ≤0.1 ng/g. In addition, the method uses less toxic and smaller quantities of solvents and chemicals.
Rapid Screening Method for Aflatoxin M1 in Milk
Authors: Holaday Charles E 
Published: February 2020

Abstract
A rapid screening method for detecting aflatoxin M1 in milk has been developed, based on minicolumn chromatography and requiring 8-10 min for each test. The minicolumn is packed with dry Florisil (100-200 mesh) on the bottom, anhydrous Na2S04 as the next layer, topped with neutral alumina (70-200 mesh) to which 8% water (wet basis) has been added. A blue fluorescent band at the Florisil-Na2SO4 interface indicates the presence of aflatoxin M1. The limit of detection is estimated to be about 0.2 μg/kg. Because several items are disposable, both the time to maintain glassware and the cost per determination are reduced.
Improved Fluorometric-Iodine Method for Determination of Aflatoxin in Corn
Authors: Davis Norman D , Guy Mary L , Diener Urban L 
Published: February 2020

Abstract
Several innovations in the fluorometric-iodine (FL-I) method for determining aflatoxin in corn made the procedure faster and more convenient than the original method. Ground corn was packed into a chromatographic column and the aflatoxins were extracted with methylene chloride. Sep-Pak C18 cartridges were used for sample cleanup. A 5 min thin layer chromatographic slide analysis confirmed the presence of aflatoxin, which was quantitated by f luorometric determination of the iodine derivative of aflatoxin B1.
Effect of Bentonites on Fluorometric Selenium Determination
Authors: Olson Oscar E , Herr Ailene A , Palmer Ivan S 
Published: February 2020

Abstract
Bentonites in feeds cause error in the analysis for Se by the AOAC (3.097-3.101) fluorometric method for Se in plants. The error apparently results from the binding of the piazselenol by insoluble residue from the bentonite. This effect is avoided by diluting digests to volume after reduction with HCl, centrifuging or allowing to stand, and analyzing a portion of the clear supernatant liquid. Insoluble residues present after digestion of plant materials do not appear to cause a similar error.
Degradation of Methomyl Residues in Frozen Strawberries
Authors: Wheeler Willis B , Thompson Neal P , Edelstein Robert L , Krause Richard T 
Published: February 2020

Abstract
14C-Methomyl (S-methyl N-[(methylcarbamoyl)-oxy]thioacetimidate) suspended in a commercial formulation was sprayed on strawberries. At 7 and 14 days post-application, mature berries were harvested and chopped. Fresh chopped berries were extracted with methanol using a Polytron homogenizer, and the crop marc was subsequently leached with methanol, freeze-dried, and re-extracted. Portions of the fresh chopped fruit were also frozen at −20°C for 1,30, and 120 days before extraction with methanol using a Polytron homogenizer, followed by subsequent leaching of the crop marc. For fresh berries, 93.7 and 88.9% of the 14C present at harvest was extractable at 7 and 14 days post-application, respectively. Based on thin layer chromatographic analysis, methomyl represented 83.5 and 68.2% of the 14C extracted from fresh berries at 7 and 14 days, respectively. Freezing of strawberries reduced extraction efficiency and appeared to degrade methomyl. At 7 and 14 days post-application, averages of 80.9 and 77.1%, respectively, of the 14C present were extractable after frozen storage regardless of storage time. Furthermore, only about 10% of the extracted 14C was methomyl; the remainder was of unknown composition.
Gas-Liquid Chromatographic Method for Determining Oxamyl in Peppers, Tomatoes, and Cucumbers
Authors: Greenberg Rachel S 
Published: February 2020

Abstract
A simple and fast gas-liquid chromatographic method has been developed to determine residues of oxamyl insecticide in peppers, tomatoes, and cucumbers. Following sample extraction with ethyl acetate and cleanup on an alumina column, the compound is determined using a thermionic nitrogen-phosphorus detector. The limit of detection is 0.02 ppm based on a 40 g sample. Average recoveries for oxamyl at 0.025-1.0 ppm for all 3 products were 88-97%.
Gas Chromatographic-Mass Spectrometric Characterization of an Alteration Product of Malathion Detected in Stored Rice
Authors: Hansen Lydell B , Castillo Gabriel D , Biehl Edward R 
Published: February 2020

Abstract
Four alteration products of malathion have been observed in crop extracts of rice, which may not be readily identifiable in a typical gas chromatographic-mass spectrometric (GC-MS) analysis of the residues. Extracts of rice containing malathion and several related compounds were analyzed on gasliquid chromatographic (GLC) columns of different polarities. The methyl ethyl succinate ester of malathion co-elutes with malaoxon from a nonpolar GLC column. Retention data and GC-MS analysis indicate the presence of 3 previously reported compounds. Evidence was obtained for a fourth compound, O-methyl O-ethyl S-(l,2-bis-carbethoxy) ethyl phosphorodithioate, apparently resulting from the environmental alteration of malathion.
Care of Reverse Phase High Performance Liquid Chromatographic Columns When Injecting Extracts of Fat- or Oil-Based Preparations
Authors: Rabel Fredric M 
Published: February 2020

Abstract
When analyzing extracts of pharmaceutical preparations, the chromatographer may place some of the base fats or oils onto the reverse phase analytical column with each injection. This is not a problem if they are washed free from the column periodically. If not cleaned off the column, column efficiency and selectivity can be lost forever. A simple procedure is described for washing columns.
Automatic Karl Fischer Titration of Moisture in Grain
Authors: Jones Frank E , Brickenkamp Carroll S 
Published: February 2020

Abstract
Automatic Karl Fischer titrators of the motor-driven buret type and the coulometric generation type were applied to the determination of moisture in grain. Techniques were developed to optimize the performance of the Karl Fischer titration method and to overcome disadvantages attributed to it. The imprecision (1 standard deviation) of a determination is typically 0.06% moisture content at a moisture content of 15%; the systematic uncertainty from known sources is estimated to be ±0.05% moisture content at a moisture content level of 15%. It is suggested that the method be designated as the primary reference method for grain in general and for corn and soybeans in particular.
Determination of Internal Insect Infestation of Wheat: Collaborative Study
Authors: Trauba Richard L 
Published: February 2020

Abstract
An improved method has been developed for determining internal insect infestation of wheat kernels. The method involves acid hydrolysis of cracked wheat, wet sieving to remove the acid, transferring to a 2 L Wildman trap flask, deaeration by boiling, and treatment with Tween 80-Na4EDTA. Insects are extracted with light mineral oil. Reports from 6 collaborators showed that recovery was 95.92% for adult insect heads and 97.22% for larvae by the proposed method as compared with 87.05% and 6.12%, respectively, by the official method. The method has been adopted official first action.
Liquid Chromatographic Separation of Some Alkylaminocyclohexanecarbonitriles from Phenylcyclohexylamines Related to Phencyclidine
Authors: Wall George M , Clark C Randall 
Published: February 2020

Abstract
The synthesis of five 1-aminocyclohexanecarboni-Iriles and the corresponding 1-phenylcyclohexylamines related to phencyclidine is reported. The compounds are separated by reverse phase liquid chromatography in an acidic methanol-water solvent system.
Comparison of Yeast and Mold Counts by Spiral, Pour, and Streak Plate Methods
Authors: Zipkes Marilyn R , Gilchrist James E , Peeler James T 
Published: February 2020

Abstract
Foods with naturally occurring yeast and mold were used in a comparative study of 4 plating techniques. Oats, green beans, and cheese were incubated for 3 and 5 days at 25°C. Although 3 days of incubation would be sufficient for yeast, 5 days were necessary for the mold count. The percent recovery of yeasts and molds by the spiral and streak methods ranged from 200 to 357% compared with the pour plating method described in the Bacteriological Analytical Manual (BAM). The spiral method had the highest overall recovery and the lowest replicate plating error.
Gas-Liquid Chromatographic Method for Analysis of Pentachloronitrobenzene Formulations: Collaborative Study
Authors: Hanks Alan R 
Published: February 2020

Abstract
A collaborative study has been conducted on a gasliquid chromatographic (GLC) method for determining pentachloronitrobenzene (PCNB) in formulations. Wettable powder, liquid, and granular matched pairs of commercial products were analyzed by 17 laboratories using peak height measurements and by 12 laboratories using integrator area measurements. Samples were dissolved in chloroform and aliquots were mixed with internal standard before GLC analysis on a 5% SE-30 column. Mean coefficients of variation for the completed study were 1.54% for integrator area measurements and 1.35% for peak height measurements. The method has been adopted official first action.
Comparison of Enzymic, Gas-Liquid Chromatographic, and High Performance Liquid Chromatographic Methods for Determining Sugars and Organic Acids in Strawberries at Three Stages of Maturity
Authors: Reyes Felix G R , Wrolstad Ronald E , Cornwell Christopher J 
Published: February 2020

Abstract
Free sugars and major nonvolatile organic acids present in strawberries at 3 degrees of ripeness were determined by 3 analytical methods: enzymic, gasliquid chromatographic, and high performance liquid chromatographic. Results showed that variability in sugar composition due to both degree of ripeness and method of analysis was greater for sucrose than for glucose and fructose. Sucrose was almost completely hydrolyzed in the overripe fruit. Acid results showed that there was little variation in citric acid levels due to ripeness or method of analysis; malic acid, however, decreased greatly in overripe fruit. Malic acid also showed high variability due to method of analysis. The glucose:fructose ratios for the underripe, ripe, and overripe fruit were 0.86,0.92, and 0.60, respectively. The citric:malic ratios were 1.58, 2.39, and 14.86 for the underripe, ripe, and overripe stages, respectively.
Gas Chromatographic- Atmospheric Pressure Active Nitrogen Method for Organomercury Speciation in Environmental Samples
Authors: Rice Gary W , Richard John J , D'Silva Arthur P , Fassel Velmer A 
Published: February 2020

Abstract
Methods are presented for the determination of methylmercury in fish, water, urine, and sediments, and diorganomercury compounds in water. Two significant differences from previous methods are the use of methylene chloride extracting solvent which permits sample extracts to be concentrated to volumes as low as 0.1 ml, and use of a gas chromatograph interfaced to an atmospheric pressure active nitrogen (APAN) afterflow detector. Such a detector is very sensitive and selective for Hg at picogram levels. Thus, limits of detection were significantly enhanced.
Polarographic Determination of Kjeldahl Nitrogen
Authors: Fosdick Lawrence E , Pike Richard K 
Published: February 2020

Abstract
A simple and rapid method is described for determining ammonia content of a Kjeldahl digest by polarography. The digest is diluted and pipetted into a solution of formaldehyde in an acetate buffer. The hexamethylenetetramine produced by reaction between ammonia and formaldehyde is determined electrochemically at μ1.04 V. Three different samples (milk, bread, and cashews) were analyzed and Kjeldahl nitrogen showed an average relative standard deviation of 3.4%; repetitive analyses of the same digest demonstrated a relative standard deviation of 1.5%.
High Pressure Liquid Chromatographic Determination of Monoand Disaccharides in Presweetened Cereals: Collaborative Study
Authors: Zygmunt Lucian C ,   Collaborators:, Anderson E , Behrens B , Bowers R , Bussey M , Cohen G , Colon M , Deis C , Given P S , Granade A , Harms C , Heroff J C , Hines D , Hung G W , Hurst W J , Keller J , Laroche F B , Luth W , McKay D , Mertle T , Navarre M , Rivera R , Scopp R , Scott F , Sherman R , Sloman K , Sodano C , Trick K D , Vandine B R , Webb N G 
Published: February 2020

Abstract
A collaborative study was conducted using a modified AOAC method (sugars in chocolate) for the determination of fructose, glucose, sucrose, and maltose in presweetened cereals by high pressure liquid chromatography (HPLC). Eight samples consisting of 6 products were analyzed in duplicate by the HPLC method and the AOAC Lane-Eynon method. The AOAC method was modified to use water-alcohol (1 + 1) and Sep-Pak C18 cartridges for sample cleanup. The HPLC results indicate precision comparable to the Lane-Eynon method and the chocolate method. The modified HPLC method has been adopted official first action.
The Next Decade: Sound Methodology and Legal Actions
Authors: Levine Arthur N 
Published: February 2020

Abstract
Regulatory agencies become involved in numerous "legal actions." Not only do these agencies initiate legal actions to enforce laws, they promulgate rules, issue statements of policy, and develop and define statutory standards. Not surprisingly, these programs are challenged in courts by members of regulated industry, trade associations, consumer groups, and individual citizens. Regulatory agencies also initiate and respond to a variety of issues by administrative, rather than judicial, action. These too are "legal actions" and frequently concern the adequacy of laboratory and scientific methodology. Where the agency initiates action to enforce the law, it carries the burden of proof. Where agency action or inaction is challenged, the challenging party carries the burden of proof and the courts have frequently given great deference to the views of the agency. However, the courts will frequently evaluate for themselves the scientific basis for the agency’s decision, regulation, or program. Examples of judicial reaction to scientific questions in recent years will be discussed.
Simultaneous Determination of Vitamins A and D in Dosage Forms by High Pressure Liquid Chromatography
Authors: Ines Maria , Santoro R M , Magalhães João F , Hackmann Erika R M 
Published: February 2020

Abstract
Vitamins A and D were determined simultaneously in oily solutions, ointments, and elixirs, but only vitamin A could be determined in capsules. Samples were saponified with KOH in isopropanol-water, using hydroquinone as antioxidant, and extracted with ether-petroleum ether (1 + 1). After evaporation of solvent, residues were dissolved in isopropanol. Vitamins in these solutions were determined by reverse phase high pressure liquid chromatography, using methanol-water as mobile phase and detection at 254 nm. The reproducibility, using external standards, was 1.6-2.5% and 1.2-3.8% for vitamins A and D, respectively.
Identification and Confirmation of Pyrantel- and Morantel-Related Residues in Liver by Gas Chromatography-Mass Spectrometry with Selected Ion Monitoring
Authors: Lynch Martin J , Bartolucci S Richard 
Published: February 2020

Abstract
A gas chromatographic-mass spectrometric method with selected ion monitoring (GC/MS-SIM) is described for identification of pyrantel- and morantel- related residues in swine and beef liver. Alkaline hydrolysis of tissue liberates and converts pyrantel-and morantel-related residues to 3-(2-thienyl)-acrylic acid (TAA) and 3-(3-methyl-2-thienyl)-acrylic acid (MTAA), respectively. These thienyl acrylic acids are recovered by ion exclusion chromatography and converted to methyl ester derivatives (TAAE and MTAAE) for identification by GC/MS-SIM. When the relative intensities of the molecular ion, the base peak, and a third significant ion of the sample correspond to ion intensities of the preformed or processed standards, the identity of the residue is confirmed. The method was validated by analysis of swine and beef liver samples containing incurred residues of pyrantel and morantel under withdrawal conditions.
Factors Affecting the Determination of Citrate-Insoluble Phosphorus
Authors: Johnson Frank J , Farley James A 
Published: February 2020

Abstract
Interlaboratory imprecision of results for citrate-insoluble P2O5 is greater than desired, especially for analyses of triple superphosphate (TSP). A systematic study of the method indicates that the most significant contributor to the imprecision is the fineness of the ground sample. Other factors affecting results are sample weight, bath temperature, and extraction time. Comparable results are reported for TSP analyzed by the AOAC official method on samples prepared by grinding to –20 + 200 mesh, on unground samples, and on samples disintegrated by an ultrasonic bath. Similar tests on diammonium phosphate, using the same 3 sample preparation techniques, yield results that are not comparable.
High Pressure Liquid Chromatographic Determination of Aflatoxins in Peanut Butter Using a Silica Gel-Packed Flowcell for Fluorescence Detection
Authors: Francis Octave J , Lipinskl Leo J , Gaul Jean A , Campbell Alfred D 
Published: February 2020

Abstract
A high pressure liquid chromatographic method has been developed for determining aflatoxins B1, B1 G1, and G2 in peanut butter. The method is based on extraction with acidified aqueous methanol, partition of the aflatoxins into methylene chloride, and purification of the extract on a 2 g silica gel column. The extracted aflatoxins are resolved on a microparticulate (10 μm) porous silica gel column in ca 10 min with a water-washed chloroform-cyclohexane-acetonitrile solvent that contains 2% isopropanol. The fluorescence detection system determines aflatoxins B1, B2, G1, and G2 at low levels, i.e., 0.25 ppb B1, 0.5 ppb G1, and 0.2 ppb B2 and G2. Multiple assays of 5 samples of naturally contaminated peanut butters containing total aflatoxins (B1 + B2 + G1 + G2) at levels of 1,2,3, 9, and 17 ppb gave intralaboratory coefficients of variation of 7,4,4,11, and 3%, respectively. Samples spiked at levels of 5, 9, and 17 ppb total aflatoxins showed recoveries of 79, 81, and 81%, respectively.
Terbufos and Its Metabolites: Identification by Gas-Liquid Chromatography and Mass Spectrometry
Authors: Wei Lester Y , Felsot Allan S 
Published: February 2020

Abstract
Methods have been developed for identification of terbufos, terbufos sulfoxide, terbufos sulfone, terbufoxon, terbufoxon sulfoxide, and terbufoxon sulfone by mass spectrometry. Residues of terbufos and terbufos sulfone fortified in soil samples at 5 ppm were extracted and analyzed successfully by gas chromatography and mass spectroscopy.
Rapid Screening Test for Sulfamethazine in Swine Feeds
Authors: Schwartz Daniel P 
Published: February 2020

Abstract
A simple, 10-min qualitative screening test for sulfamethazine (SM) in swine feeds is detailed. The method, which can be run in the field, uses 2 plastic tubes arranged piggyback style. The upper tube contains, from top to bottom, the feed sample (about 1 g), partially deactivated alumina, and an anion exchange resin buffered at pH 5.7. The bottom tube contains a small bed of anion exchanger buffered at pH 7.9, which traps the SM. After percolation of solvent through the system, the SM, if present, is eluted from the pH 7.9 resin and is reacted with Bratton-Marshall reagents to give a pink-to-lavender color. Feeds containing ≥0.15 ppm can be detected. A simple, additional dye concentration step allows for detection of 0.02 ppm, if desired. Only amphoteric primary aromatic amino-containing compounds with a pKa close to that of SM can theoretically interfere. Preparation of permanent color solutions using cobalt and copper acetates in glacial acetic acid is described for the optional establishment of the minimum concentration of SM in the feed. The method offers a simple way to detect some cross-contaminated withdrawal feeds containing &gt;2 ppm SM, which can lead to violative (≥0.1 ppm) residues in swine liver.
Electrophoretic Method for Qualitative and Quantitative Analysis of Gelling and Thickening Agents
Authors: Pechanek U D O , Blaicher Gernot , Pfannhauser Werner , Woidich Herbert 
Published: February 2020

Abstract
An electrophoretic method has been developed for qualitative and quantitative determination of all common thickening and gelling agents. Thickeners were identified by their migration behavior, their staining ability, and the characteristic shapes of their electrophoretic zones, and then quantitated in a scanner. A method is also reported for isolating thickeners from food, including removal of fat and dyes by dioxane, enzymatic starch degradation, removal of protein by trichloroacetic acid, and precipitation of the polysaccharides by absolute ethanol. Isolation of gelatin is also described.
Reverse Phase High Performance Liquid Chromatographic Determination of Phenprocoumon in Tablets
Authors: Schmidt Walter F 
Published: February 2020

Abstract
A high performance liquid chromatographic procedure has been developed for the assay of phenprocoumon in tablets. In comparison to the present official USP assay procedure, it is equivalent in precision and accuracy and is faster and more specific. A mobile phase consisting of a 1% solution of acetic acid in acetonitrile-water (4 + 3) separates phenprocoumon from warfarin internal standard on a 6 μm octadecylsilane (ODS) column with UV detection at 311 nm. The method enables the concurrent determination of phenprocoumon and possible contaminants such as salicylic acid.