bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gas-Liquid Chromatographic Quantitation of Pheneyclidine.HCl in Powders: Collaborative Study
Authors: Clark Charles C 
Published: February 2020

Abstract
Six laboratories collaboratively studied a method for the quantitative gas-liquid chromatographic (GLC) determination of pheneyclidine. HCl in powders. The pheneyclidine.HCl and other water-soluble compounds are dissolved in dilute HC1. A portion of the aqueous solution is made weakly basic with K2HPO4, and the organic-soluble compounds are extracted in CHCI3 for the GLC determination of the pheneyclidine.HCl. Eicosane (n-C20) is incorporated in the extracting CHC13 as an internal standard. The samples collaboratively studied included samples of known pheneyclidine. HCl concentration and one sample of unknown purity. Recoveries ranged from 92.1 to 104% and per cent standard deviations from 1.05 to 3.39. The method was adopted as official first action.
Thin Layer Chromatographic Determination of Aflatoxins, Ochratoxins, Sterigmatocystin, Zearalenone, Citrinin, T-2 Toxin, Diacetoxyscirpenol, Penicillic Acid, Patulin, and Penitrem A
Authors: Gimeno Alberto 
Published: February 2020

Abstract
A general method is described for determining 16 mycotoxins in mixed feeds and other food products used in the manufacture of these feedstuffs. The mycotoxins are extracted and cleaned up by extracting with solvents of different pH. Thin layer chromatography is used to separate the toxins; toxins are then quantitated by the limit detection method. The minimum detectable concentration of mycotoxins in various products is: aflatoxin B1 or G1, 4–5 μg/kg; cchratoxin A or ethyl ester A 140–145 μg/kg; citrinin 600–750 μg/kg; zearalenone, 410–500 μg/kg; sterigmatocystin, 140–145 μg/kg; diacetoxyscirpenol, 2400–2600 μg/kg; T-2 toxin, 800-950 μg/kg; patulin, 750-800 μg/kg; penitrem A 14,000–14,500 μg/kg; penicillic acid 3400-3650 μg/kg.
Mineral Oil Extraction of Light Filth from Rubbed Sage Collaborative Study
Authors: Colliflower Emma J , Thrasher Joel J 
Published: February 2020

Abstract
The official methods for extracting light filth from rubbed sage, 44.D08–44.D10, specifies a hot isopropanol pretreatment and flotation from cooled dilute isopropanol with mineral oil to extract light filth. The method gives good recoveries, but occasionally excessive interfering plant material is extracted along with the filth elements. A new method has been developed in which chloroform is used for pretreatment instead of isopropanol, and Tween 80-EDTA is added twice rather than once. This method has given consistently cleaner filter papers and better recoveries for rodent hairs, 85 vs. 79%, and for elytral squares, 95 vs. 84%. The new method has been adopted as official first action.
Extraction of Light Filth from Canned Green Leafy Vegetables: Collaborative Study
Authors: Dent Russell G , Boese Jack L 
Published: February 2020

Abstract
The official first action method, 44.108, for the extraction of light filth from whole or chopped canned greens specifies a waterheptane flotation that results in the flotation of an excessive amount of interfering plant material and in low recoveries. A new method has been developed using a 40% isopropanol-watermineral oil flotation. The new method yielded a decreased amount of plant material and 84.9% recovery of the aphid spike compared with 42.5% recovery of the spike by the official method. The new method has been adopted as official first action to replace the existing method, except for broccoli.
New Brine Saturation Technique for the Extraction of Light Filth from Rubbed Sage, Paprika, and Corn Meal: Intralaboratory Study
Authors: Freeman Clarence C 
Published: February 2020

Abstract
A new and widely applicable technique for the isolation of light filth from foods has been developed. It includes a simple alcohol defatting followed by a brine saturation of the product by heating and cooling and a subsequent trapping of the filth elements with olive oil and tap water. The methods circumvent the use of hazardous and expensive solvents and lengthy defatting and/or pre-treatment procedures. In an intralaboratory study, recoveries of elytral squares and rodent hair fragments added to paprika, rubbed sage, and corn meal ranged from 95.8 to 100%.
Gas-Liquid Chromatographic Determination of Monosodium Glutamate in Soups and Soup Bases
Authors: Conacher Henry B S , Iyengar Jagannath R , Miles Walter F , Botting Herbert G 
Published: February 2020

Abstract
A method is given for determining monosodium glutamate (MSG) in soups and soup bases by gas-liquid chromatography (GLC) of the trimethylsilyl ether derivative of glutamic acid. This method compared favorably with existing methods including GLC of the trifluoroacetate (TFA) /butyl ester derivative, and analysis on an amino acid analyzer. In addition, some samples were analyzed by GLC/mass spectrometry. The MSG content of various products ranged from approximately 0.2% in some condensed soups to 13.1% in bouillon cubes. The method, which can detect as little as 0.05%, requires only a 10 min single step derivatization at room temperature and is preferred to the TFA/butyl ester technique.
High Pressure Liquid Chromatographic Determination of Vitamins A and E in Cereal Products
Authors: Widicus Warren A , Kirk James R 
Published: February 2020

Abstract
A rapid method for the simultaneous determination of vitamins A and E in fortified cereal products has been developed. Saponification of retinyl or tocopheryl esters is not required, permitting direct injection of the extracted lipids onto the high pressure liquid chromatographic column without sample cleanup. Elution times of 2.46 and 3.40 min were determined for retinyl palmitate and tocopheryl acetate, respectively, using a μPorasil column and an isocratic mobile phase of hexane-chloroform (85+15) with a flow rate of 1.5 mL/min. The average recovery of retinyl palmitate was 99.2% (std dev. 4.28), and the average recovery of tocopheryl acetate was 94.9% (std dev. 4.10) in 2 cereals containing corn, oat, rice, and wheat. No significant amounts of naturally occurring tocopherols were found in the cereals.
Automated Fluorometric Determination of Thiamine and Riboflavin in Infant Formulas
Authors: Dunbar Walter E , Stevenson Kenneth E 
Published: February 2020

Abstract
Commercial infant formulas were analyzed simultaneously for thiamine and riboflavin by an automated fluorometric method and by the AOAC manual fluorometric methods. For 10 products, the mean thiamine and riboflavin results determined using the automated method ranged from 104 to 113% and 90 to 112%, respectively, of those by the AOAC manual methods. The coefficients of variation for thiamine and riboflavin ranged from 1.05 to 3.90% and 0.60 to 2.48%, respectively, for the automated method, and 1.48 to 3.86% and 0.69 to 10.9%, respectively, for the manual methods. Using the automated method, mean recoveries of thiamine and riboflavin added to samples were 103 and 104%, respectively. The automated method used a common sample preparation to determine both thiamine and riboflavin, and gave results equivalent to, or better than, those obtained by the manual methods.
Pyridine Extraction Method for Determination of Bacitracin in Feeds: Collaborative Evaluation
Authors: Ragheb Hussein S 
Published: February 2020

Abstract
Seventeen laboratories evaluated the pyridine extraction method and neomycin-sensitized agar for the determination of zinc and MD bacitracin in swine and broiler rations at 10 and 100 g/ton. The method was also applied to the analysis of 2 premixes labeled 50 g/lb (MD bacitracin) and 40 g/lb (zinc bacitracin). Bacitracin activity was determined on each of 2 days with 2 dilutions on each day. No significant difference was found between dilutions within a day or between days for each sample. The type of bacitracin or type of feed did not significantly affect results. The difference in results between MD and zinc bacitracin in premixes approached significance. The large coefficients of variation for premixes (ca 13%) and complete feeds (ca 15–30%) indicate operational problems. The main difficulty was evaporation of pyridine. Some laboratories were not able to evaporate it completely, whereas others lost bacitracin activity, probably due to high temperature of drying. The pyridine extraction method as in 42.200 and 42.204 should be discontinued.
Determination of Chlorinated Pesticide Residues in Foods. II. Potassium Permanganate Oxidation for Cleanup of Some Vegetable Extracts
Authors: Suzuki Takashi , Ishikawa Kiyoshi , Sato Nobutoshi , Sakai Kei-Ichi 
Published: February 2020

Abstract
A potassium permanganate-dilute sulfuric acid KMnO4/dilute H2SO4 oxidation procedure was developed to supplement Florisil cleanup of some vegetable extracts. Following sample preparation and Florisil cleanup, a reaction mixture of the n-hexane eluate from the Florisil cleanup, 4% KMnO4, and 40% H2SO4 (l+l+l) was shaken in a test tube 2 min at room temperature and then centrifuged. The n-hexane phase was washed with 2 mL 0.1N NaOH and analyzed by GLC. Twelve chlorinated pesticides were completely recovered in the n-hexane phase. Aldrin was not recovered because its extreme instability caused it to decompose even in neutral solutions. Chlorinated pesticide residues in onion, garlic, carrot, and radish root were easily analyzed by the application of this oxidation procedure.
Evaluation of Two-Way Riffles for Precise Division of Blended Fertilizers
Authors: Woodis Terry C , Holmes John H , Hunter G Bradley , Johnson Frank J 
Published: February 2020

Abstract
Evaluation of two-way riffles showed that gated riffles are superior to open-chute riffles. The proper technique appears to play a significant role in subdivision of blended fertilizers with the open-chute riffle, while the use of the gated riffle virtually eliminates error due to technique. A blended fertilizer prepared from materials having disparate particle sizes can be divided with a gated riffle to give a subsample that is representative of the original lot.
High Pressure Liquid Chromatography of Ester and Salt Formulations of 2-Methyl-4-Chlorophenoxyacetic Acid
Authors: Stevens Timothy , Grorud Robert B 
Published: February 2020

Abstract
A high pressure liquid chromatographic (HPLC) assay of amine salt and ester formulations of MCPA has been collaboratively studied. The AOAC 2,4-D HPLC method has been modified for application to MCPA products. The MCPA methodology is identical to that of 2,4-D except in strength of mobile solvent, pH of mobile solvent, heating of ester formulations to 50°C to ensure complete saponification, and the use of glass microfiber filters. The method is specific and separates all known impurities. Examination of chromatograms and percentage results from 8 collaborators indicate that selection of a practical internal standard would improve precision in the procedure and a second collaborative study is recommended.
Preparation and Spectral Analysis of 3,3',4,4'-Tetrachloroazobenzene and the Corresponding Azoxy and Hydrazo Analogs
Authors: Hsia M T Stephen , Burant Charles F 
Published: February 2020

Abstract
An efficient preparation was developed for 3,3',4,4'-tetrachloroazobenzene and the corresponding azoxy and hydrazo derivatives, based on the lithium aluminum hydride reduction of 3,4-dichIoronitrobenzene. Batches were analyzed for purity by using a reverse phase high pressure liquid chromatographic method. All 3 compounds can be synthesized in gram quantities with 97–99% purity. Detailed mass, infrared, and nuclear magnetic resonance spectral analyses are presented.
Gas-Liquid Chromatographic Determination of Thiabendazole and Methyl 2-Benzimidazole Carbamate in Fruits and Crops
Authors: Tjan Gwan H , Jansen John T A 
Published: February 2020

Abstract
A method is described for the electron capture gas-liquid chromatographic determination of thiabendazole and methyl 2-benzimidazole carbamate (MBC) after derivatization with pentafluorobenzyl bromide (PFB-Br). The samples are extracted with ethyl acetate, and the residual thiabendazole, benomyl, and MBC are isolated by liquid-liquid extraction into dilute HC1. After neutralization and re-extraction with ethyl acetate, thiabendazole and MBC are reacted with PFB-Br to form the PFB derivatives. Alumina column chromatography was used to clean up extracts, and the derivatives could be detected as low as 5–10 pg. Recoveries were 95-98% from fruits fortified with 0.3-2.0 ppm thiabendazole; recoveries were 91–97% when 0.05–1.0 ppm benomyl/MBC were added to fruits/crops. The PFB derivatives were identified by gas-liquid chromatography-mass spectrometry.
Rapid Methods for Differentiating Reactivated from Residual Phosphatase in Milk and Cream: Collaborative Study
Authors: Murthy Gopala K , Peeler James T 
Published: February 2020

Abstract
Three methods for differentiating reactivated from residual phosphatase in milk and cream were collaboratively tested using both magnesium acetate and magnesium chloride for reactivating phosphatase. The methods evaluated were the modified Scharer rapid test, the rapid colorimetric test, and the Rutgers method. Nine collaborators tested 6 unknown milk samples containing reactivated and/or residual phosphatase, and 16 collaborators tested 6 unknown cream samples containing reactivated and/or residual phosphatase. Results indicated that use of magnesium acetate in place of magnesium chloride for reactivating phosphatase improved test results. Visual tests (modified Scharer rapid and Rutgers) predicted correct results when the samples contained high levels of reactivated or residual phosphatase. In borderline cases where the reactivated phosphatase contents of the undiluted control sample and the diluted sample containing Mg were very close, the test results of the visual methods were significantly different from 100% correct results at the α = 0.05 level. Use of a photoelectric colorimeter or its equivalent for measuring the absorbance in conjunction with the modified Scharer rapid test improved results considerably. The modified Scharer rapid test was adopted official first action.
Modified Karl Fischer and Vacuum Oven Moisture Methods for Cheese Products: Comparative Study
Authors: Christen Genevieve L , Richardson Gary H 
Published: February 2020

Abstract
In a modified Karl Fischer method, methanolchloroform (1+1) was used to extract moisture from cheese after homogenization in an automatic titrimeter. The mean coefficient of variance was high (0.82%) for the modified apparatus as determined by the values obtained during computation of the Karl Fischer factor. Variance from other sources in the assay was not significant. Comparative data on 6 different cheese samples produced within-day coefficient of variance values from 0.46 to 0.85%, following discard of outlying data, compared to 0.12 to 0.30% for within-day values obtained using the official vacuum oven method. A sample could be assayed in 7 min. The apparatus costs less than equipment required for some rapid methods; however, solvent and reagent costs, high coefficient of variance values, and the need for expensive reagents suggest that this approach is impractical for extracting moisture from cheese products.
Interlaboratory Comparison of Behavioral Testing
Authors: Butcher Richard E , Hoar Richard M , Nolan Granville A , Vorhees Charles V 
Published: February 2020

Abstract
New requirements by several regulatory agencies for testing the psychotoxic potential of new drugs, chemicals, and environmental contaminants raise unique problems. In order to assess intra- and interlaboratory reliability of behavioral tests a model animal maze learning procedure was designed and run in 3 cooperating laboratories. Uniform procedures were written and identical mazes were constructed. Normal control animals of identical age and sex, but of different strains, were used by the participants. A positive control group of neurologically impaired rats was run by one laboratory. Significant differences in test results among the laboratories were found. Data obtained from the positive control animals (X− errors = 28.3) indicated a learning impairment statistically significant compared to the negative control data (X− errors = 12.7) from any of the participating laboratories. Based on the results of this study, a reasonable standard of interlaboratory reliability in behavioral testing appears an attainable goal.
Collaborative Studies on the Salmonella/Microsome Mutagenicity Assay
Authors: Dunkel Virginia C 
Published: February 2020

Abstract
Although the Salmonella/plate test has been used extensively, a collaborative study was undertaken to determine the interlaboratory reproducibility of this microbial mutagenicity assay. Four laboratories participating in the study have completed testing, under code, of 61 carcinogens and noncarcinogens. All chemicals were tested both with and without metabolic activation in Salmonella typhimurium strains TA1535, 1537, 1538, 98, and 100. The metabolic activation systems used were derived from the livers of both uninduced and Aroclor 1254-induced Fischer rats, B6C3F1 mice, and Syrian hamsters. Analysis of the results on 23 of the chemicals tested in 3 of the participating laboratories showed that 8 were negative when tested in all laboratories and 13 were positive. Two chemicals gave positive results in 2 laboratories; the same 2 chemicals were negative when tested in the third laboratory.
Overview and Status of in vitro Transformation
Authors: Sivak Andrew 
Published: February 2020

Abstract
The development of standardized assay procedures has permitted the exploitation of cell culture systems as bioassay tools for the detection of chemical carcinogens. These systems fall generally into 3 classes: diploid cell strains, Syrian hamster embryo cells; cell lines, mouse BALB/c-3T3 and mouse C3H-10½; and cells + virus, Fischer rat cells infected with Rauscher leukemia virus and Syrian hamster embryo cells infected with adenovirus. The results accumu-lated to date show a good correlation between transformation response in cell culture and carcinogenicity of chemicals in whole animal studies. The major advantages of these systems are their relative brevity (10 days–6 weeks) and resultant low costs, their agreement with whole animal bioassays, and their direct biological relevance to the carcinogenic process. The present major disadvantages are the uncertain nature of the metabolic capabilities of the target cells and the lack of a metabolic activation system that is reliable and adaptable for routine bioassays. The development of epithelial cell systems such as breast, liver, lung, and skin may solve the problem of carcinogen metabolism as well as provide target cells that are representative of major organ sites for cancer in man. The rational use of cell culture bioassays for neoplastic transformation is a valuable component of the toxicological armamentarium to assess risk to humans from exposure to chemicals.
Gas-Liquid Chromatographic Determination of Adipic Acid in Crackling Candy and Soft Drinks
Authors: Ito Yoshio , Ogawa Shunjiro , Iwaida Masahiro 
Published: February 2020

Abstract
A procedure was developed for the simple and rapid determination of adipic acid in crackling candy and also in soft drinks. An alkaline solution of sample was extracted with ethyl ether to remove fatty substances, and H2SO4 was added to water layer to adjust the pH to &lt;2. The acidified layer was saturated with NaCl and then extracted with ether. After drying, the ether layer was concentrated and the adipic acid in the concentrate was methylated using the diazomethane method. An aliquot of the methylated solution was injected into a gas chromatograph equipped with a flame ionization detector. Recovery of adipic acid from crackling candy and from 2 kinds of soft drinks that had been fortified at the 200 ppm level was over 96 %. An interlaboratory test was carried out on the determination of adipic acid in orange soft drink. The results obtained by 6 laboratories were between 91 and 100% compared with the theoretical value.
Instrumental Evaluation of Readily Carbonizable Substances in Citric Acid
Authors: Dokladalova Jarmila , Upton Ronald P 
Published: February 2020

Abstract
A procedure has been developed for objective evaluation of the color generated in the USP test by readily carbonizable substances in citric acid. A tristimulus instrument–Hunterlab Color Difference Meter Model D25D3P–is used. The total color and yellowness defined by the aid of APHA (American Public Health Association) color standards can be measured with a precision better than ±2.5% relative (95% confidence interval). The procedure has been used successfully in our quality control laboratories for over 2 years, and the color determined in more than 1400 samples has been in agreement with the visual evaluation as required by USP.
High Pressure Liquid Chromatographic Determination of Sodium Saccharin, Sodium Benzoate, and Caffeine in Soda Beverages: Collaborative Study
Authors: Woodward Betsy B , Heffelfinger Gordon P , Ruggles Dennis I 
Published: February 2020

Abstract
A collaborative study for the determination of sodium saccharin, sodium benzoate, and caffeine in 3 types of soda beverage, cola, grape, and lemon-lime, has been completed using reverse phase high pressure liquid chromatography with a μC18 column and acetic acid mobile phase. Recoveries for sodium saccharin were 98.6, 98.0, and 99.1%; for sodium benzoate, 100.6, 102.6, and 100.6%; and for caffeine, 100.8, 101.4, and 101.1%, respectively. The method has been adopted as official first action.
Semiautomated Method for Niacin and Niacinamide in Food Products: Collaborative Study
Authors: Egberg David C 
Published: February 2020

Abstract
collaborative study was conducted comparing a semiautomated colorimetric niacin method with a manual colorimetric and a microbiological method for 10 food products. Seven laboratories used the microbiological method, 7 laboratories used the manual colorimetric method, and 6 laboratories used the semiautomated method. The semiautomated method was more repeatable within a laboratory and more reproducible between laboratories than was either of the other methods. The semiautomated method results compared favorably with both the microbiological and manual colorimetric method results.
Analysis of Fat-Soluble Vitamins. XXII. High Performance Liquid Chromatographic Determination of Vitamin D in Concentrates. Collaborative Study1
Authors: Mulder Frits J , Vries Ellen J De , Borsje Ben 
Published: February 2020

Abstract
A collaborative study was carried out which compared the official chemical method (43.B14- 43.B24), the HPLC method according to Hofsass et al. including maleic anhydride treatment, and the HLPC procedure according to De Vries et al. for vitamin D concentrates. A total of 396 samples were distributed to 33 collaborators for analysis. Five laboratories performed both the chemical and the HPLC methods. Five laboratories performed the Hofsass method and 16 laboratories performed the De Vries method. The results for the chemical method agreed with the theoretical values for the samples, and the standard deviation was comparable to that obtained in previous AOAC collaborative studies. Collaborative results for the Hofsass method were low. In addition, incorrect use of a fixed conversion factor (1/0.586) and necessity of a double chromatographic system on a non-treated and a treated vitamin D sample reduce the effectiveness of the method. There were no adverse reactions to the De Vries HPLC method. It is recommended that the method be adopted official first action as an alternative procedure for determining vitamin D in concentrates, excluding powders containing irradiated 7-dehydrocholesterol.