bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Simplified Halphen Procedure for Cyclopropene Fatty Acids
Authors: Coleman Eugene C , Firestone David 
Published: February 2020

Abstract
A simplified Halphen procedure was developed for the quantitative determination of cyclopropene fatty acids in fats and oils. Butanol, dimethyl sulfoxide (DMSO), and mixtures of butanol and DMSO were used as reaction media in a closed system. Higher sample absorbances were produced in butanol than in mixtures of butanol and DMSO. Butanol was superior to the other solvent systems for both quantitative and qualitative analyses. The lower limit of sensitivity for the tube-butanol system for quantitative and qualitative analyses was 18 and 15 μg cyclopropene fatty acids/g oil, respectively.
Gas-Liquid Chromatographic Detection of Palm Kernel and Coconut Oils in Cacao Butter
Authors: Iverson John L 
Published: February 2020

Abstract
A gas-liquid chromatographic method for the detection of palm kernel and coconut oils in cacao butter is presented. Detection of adulteration is based on the programmed-temperature gas chromatographic analysis of lauric acid. Cacao butter naturally contains approximately 0.01% lauric acid, while coconut and palm kernel oils contain approximately 50% lauric acid. The 95% confidence interval indicated that it was possible to reliably detect 0.25% lauric acid, which corresponds to 0.5% adulteration.
Recovery of Shigella Under Acidic Conditions
Authors: Fishbein Morris , Mehlman Ira J , Wentz Barry 
Published: February 2020

Abstract
The rationale for an investigative approach in the recovery of small numbers of Shigella in the presence of large numbers of the competitive Enterobacteriaceae is discussed. On this basis, the acid production of the Enterobacteriaceae in common enrichment media is explored. The inhibition of Shigella growth initiation from small inocula (10–50 organisms/ml) by particular acid metabolites, such as formic and acetic acids, is shown. Finally, the ability of small Shigella inocula to grow in the fermented acidic media in which the Enterobacteriaceae have previously grown was studied in detail. It is recommended that the competitive factors affecting Shigella be studied further.
An Improved Screening Method for Chlorodibenzo-p-dioxins
Authors: Williams D T , Blanchfield B J 
Published: February 2020

Abstract
2,3,7,8-Tetrachlorodibenzo-p-dioxin is detected at a level as low as 0.05 ppm in corn oil by conversion to octachlorodibenzo-p-dioxin and measurement of the latter compound by electron capture gas-liquid chromatography. The method presented is based on a previously reported screening method, which has been modified to include different chlorination conditions and a subsequent alumina column cleanup.
Modified Ferric Gel Method for Determining Aflatoxin in Cottonseed Meals
Authors: Velasco James 
Published: February 2020

Abstract
The ferric gel method for determining anatoxin in cottonseed has been adapted for cottonseed meals. A change in solvent system and an additional purification step required by some meals have been incorporated into the method. Purification of these meals is accomplished by filtration rather than by chromatographic fractionation on columns of silica gel. The time of analysis as compared to the AOAC method is reduced by more than one half with this new method and total recoveries are comparable to or higher than those obtained with the AOAC method. Consideration should be given to cleanup of seed or plant extracts with ferric gel rather than with lead acetate not only because it removes plant pigments more effectively but also because it avoids the disposal of hazardous lead salts into water effluent systems.
Chromatographic Determination of Mineral Oil in Pesticide Formulations
Authors: Trombetti Giuseppe , Gordini Tullio 
Published: February 2020

Abstract
A simple method is described for the determination of mineral oil in emulsified concentrates, based on the separation of the oil from the emulsifiers by column chromatography. The emulsifiers are not eluted and the oil is determined gravimetrically after the solvent is evaporated. This method is also applicable to emulsifiable concentrates that do not contain solvents as co-formulants.
Direct Determination of Potash in Fertilizers by Atomic Absorption Spectrophotometry
Authors: Thorpe Virginia A 
Published: February 2020

Abstract
A rapid atomic absorption method is presented for the direct determination of potash in fertilizers, using the extract prepared for available phosphorus without dilution. By using the secondary potassium line and scale expansion, sensitive linear curves were obtained for 100–1000 ppm, covering K2O guarantees in all fertilizers.
Gravimetric Determination of Saccharin in Cider
Authors: Markus John R 
Published: February 2020

Abstract
Samples of spiked and unspiked cider were analyzed for saccharin by 18 laboratories, using the official final action gravimetric method, 20.145(a)-20.146. Recoveries for 30.5 mg saccharin added/100 g cider ranged from 25.6 to 32.9 mg/100 g (83.9 to 107.9%, respectively). The mean recovery was 28.1 mg/100 g (92.8%), with a standard deviation of ±1.95 mg/100 g.
Simplified Method for the Determination of Ethoxyquin in Alfalfa Products and Mixed Feeds
Authors: Witt S C , Bickoff E M , Kohler G O 
Published: February 2020

Abstract
A simplified improved method for the determination of ethoxyquin in alfalfa products has been developed. It is based on the official AOAC photofluorometric method for ethoxyquin in animal feeds but eliminates some of the tedious steps encountered when that method is applied to ethoxyquin-treated alfalfa products. The extraction and phasic distribution steps are modified to simplify and make the method more reliable. A single total volume extraction with methanol and a single phasic distribution step with hexane are employed rather than successive partial volume extractions and partitioning steps. The increment technique is used in the fluorometric step to reduce possible errors caused by impurities which sometimes remain after phasic distribution in both methods. Results by the simplified method compare favorably with those by the official method and by a column chromatographic method for ethoxyquin. The method is also applicable to the determination of ethoxyquin in mixed feeds.
Colorimetric Method for Monensin
Authors: Golab Tomasz , Barton Steven J , Scroggs Robert E 
Published: February 2020

Abstract
A colorimetric method has been developed for the analysis of monensin, an anticoccidial agent. The principle of the method is adaptable to feeds, premixes, fermentation broth, and crystalline samples. A solution of 3% vanillin in 0.5% sulfuric acid in methanol was used as the color reagent for monensin. The method is simple, fast, sensitive (1 μg/ml), and reproducible. No interference was found with 15 other poultry feed additives.
Gas Chromatographic Determination of Low Levels of Di-(2-ethylh exyl)phthalate in Soy Oil
Authors: Williams D T 
Published: February 2020

Abstract
Di-(2-ethylhexyl)phthalate can be determined by gas chromatography at a level of 0.3 ppm in soy oil. A cleanup procedure involving epoxidation of soy oil residues with m-chloroperbenzoic acid allows confirmation of the phthalate ester by thin layer chromatography-mass spectrometry or gas chromatography-mass spectrometry.
Microbiological Assay of Oxytetracycline in Feed: Manual Turbidimetric Assay and Plate Assay
Authors: Ragheb Hussein S , Cummings Anne M , Browning Barbara M 
Published: February 2020

Abstract
The useful range for manual turbidimetric analysis of Oxytetracycline (OTC), using K. pneumoniae, was between 0.04 and 0.08 μg/ml in the assay tubes. Laboratory-prepared feeds containing 43.5 and 86.5 g OTC.HCl/ton gave 90–98% recovery by the turbidimetric method and 104–116% by the AOAC method, 38.211–38.213. The coefficients of variation were 9.2–13.0 and 10.2–12.8%, respectively. Feeds containing 50 and 100 g OTC.HCl and neomyein sulfate/ton gave 77% of theory when analyzed turbidimetrically and 95% of theory by the plate method. The coefficient of variation for the turbidimetric method was about 16%, indicating unsatisfactory precision. At 200 g/ton theoretical concentration of each antibiotic, both methods agreed. Commercial premixes and finished feed samples gave almost the same results by both methods. The main advantage of the turbidimetric method over the plate assay is that results can be obtained the same day of analysis.
Evaluation of Chemical Confirmatory Tests for Analysis of Dieldrin Residues
Authors: Maybury Ronald B , Cochrane William P 
Published: February 2020

Abstract
Eight of the more commonly used reagents for the confirmation of dieldrin at the residue level were compared for several substrates. In some instances derivatives were isolated and identified. The reactions were evaluated, using pure dieldrin and spiked sample extracts of grass, animal feeds, and butterfat. Two reagents, aqueous HBr solution and BCl3/2-chloroethanol, were especially useful because of their application and sensitivity, i.e., 0.003 ppm for a 10 g dry sample and 0.001 ppm for a 25 g wet sample. The ZnCl2/HCl reagent was a practical alternative to the BCl3/2-chloroethanol reagent. The TIBr/Ac2O reagent gave a more positive confirmation at a lower sensitivity.
Comparison of Three Extraction and Cleanup Methods for Determining Carbon-14-Labeled Residues from Wheat Plants Grown in Soil Treated with Dyfonate-Ring-14C
Authors: Saha Maitreyi , Sumner Arthur K , Saha Jadu G 
Published: February 2020

Abstract
Three methods for determining organophosphorus insecticide residues in plant tissues were compared for efficiency of extraction and cleanup of 14C-labeled residues from wheat plants grown in soil treated with Dyfonatering-14C. Blending with ethyl acetate recovered 70.5% of the radioactivity present in the plant tissues and cleanup of the extract by sweep codistillation recovered 99% of the radioactivity. Blending of plants with benzene recovered about 58% of the radioactivity and subsequent cleanup of the extract on a silica gel column recovered about 78% of the activity. Although blending with acetonitrile recovered 59% of the radioactivity present in the plant tissue, partitioning of the extract between water and petroleum ether or chloroform retained only about 14 and 30% of the activity in the organic layer, respectively. Thus, the overall efficiency of this procedure was only between 8 and 18% as compared to 45 and 70% in the other 2 methods.
Antigenic Properties of Some Insects Involved in Food Contamination
Authors: Johnson Howard M , Bukovic Joann A , Eisenberg William V , Vazquez Alberto W 
Published: February 2020

Abstract
Six common insect contaminants of food were studied antigenically for possible development of an immunoassay test for the detection of soluble insect constituents in food. Phosphate-buffered saline (pH 7.2) extracts of the insects yielded material suitable for immunization of rabbits. The extracts contained multiple antigens. Cross-reactions between antisera and antigens tended to occur between phylogenetically related insects. The data suggest that detection of insect contaminants of food by immunoassay is feasible.
Collaborative Study of the Gas-Liquid Chromatographic Determination of Sorbitol in Bakery Products
Authors: Hundley Harvey K 
Published: February 2020

Abstract
A GLC method for the determination of sorbitol has been collaboratively studied. Sugar and sugar alcohols are extracted from the bakery products by methanol and the solvent is evaporated. Acetate derivatives are then formed by addition of acetic anhydride in pyridine, and the derivatives are extracted from an aqueous solution with chloroform and analyzed by flame ionization GLC. Collaborative results show a recovery ranging from 90 to 102% sorbitol from bakery products containing 1.5 to 7% sorbitol. The method has been adopted as official first action.
Gas Chromatography of Organonitrogen Pesticides, Using a Nitrogen-Specific Detection System
Authors: Laski Ronald R , Watts Randall R 
Published: February 2020

Abstract
A gas-liquid chromatographic system with a nitrogen-specific detector was investigated for the determination of 95 organonitrogen pesticides. Each compound was chromatographed, using DC-200 liquid phase on a solid support of 80–100 mesh Chromosorb W (HP). Retention times and response data are given for these pesticides.
Differentiation of Geographic Origin of Spices. III. Lampong and Sarawak Black Pepper by Emission Spectroscopy
Authors: Kahan Gerald , Stahl William H 
Published: February 2020

Abstract
Statistical techniques applied to the data obtained for the amount of strontium, barium, and calcium found in Sarawak and Lampong black pepper are used for differentiating between the 2 varieties of pepper. Also, a regression analysis applied to the data obtained for strontium is used as a means of determining the amount of Sarawak black pepper used to adulterate pure Lampong black pepper.
Direct Titrimetric Microdetermination of Fluorodifen, Linuron, Faneron, and Pebulate
Authors: Abbas Syed L , Ghosh Asoke K , Rizvi Saiyid A I , Saxena Om C 
Published: February 2020

Abstract
The herbicides fluorodifen, linuron, faneron, and pebulate have been determined in individual standard solutions by direct titration against gallium chloride solution, using different indicators. The same technique is applied to estimation of these herbicides in treated soils. The complex between gallium chloride and fluordifen or linuron is formed in a 1:3 ratio, whereas the complex with faneron or pebulate is in a 1:1 ratio. Recoveries for fluorodifen, linuron, faneron, and pebulate were 99.9–101.5, 99.0–102.4, 97.1–101.3, and 98.3–101.2%, respectively. Treatment with herbicide lowered the pH of the soil.
Collaborative Study of the Quantitative Determination of Titanium Dioxide in Cheese
Authors: Leone Joseph L 
Published: February 2020

Abstract
A quantitative, colorimetric procedure for the determination of titanium dioxide has been subjected to collaborative study. The method incorporates ashing, dissolution of the ash in sulfuric acid, and color development using hydrogen peroxide. The Spectrophotometric response is compared to a standard prepared similarly. The yellow-to-orange color is quite stable in the absence of Fe. Other interferences are Ni, Cu, Co, Mb, Vd, and Cr. A collaborative study of cheese containing 0.05, 0.10, and 0.4% titanium dioxide gave favorable results. The method has been adopted as official first action.
Collaborative Study of a Test to Determine Whether Shucked Oysters Have Been Frozen and Thawed
Authors: Gould Edith 
Published: February 2020

Abstract
Six laboratories have collaboratively tested a method to determine whether shucked oysters have been frozen and thawed at any time. The method utilizes the differing electrophoretic migration rates of various forms of malic enzyme activity, some of which are not present in the tissue fluid until after the tissue has been frozen and thawed. The technique is enzymography, which combines electrophoresis and a specific histochemical medium. Five laboratories tested Crassostrea virginica, obtaining markedly different patterns for the unfrozen oysters compared with the frozen and thawed oysters. The sixth laboratory tested C. gigas, and was similarly successful in distinguishing between the storage treatments. In shucked oysters stored up to 3 weeks at 4°C, neither autolysis nor bacterial activity altered the enzymographic patterns. The method has been adopted as official first action.
Moisture and Fat Analysis of Meat and Meat Products: A Review and Comparison of Methods
Authors: Pettinati Julio D , Swift Clifton E , Cohen Edward H 
Published: February 2020

Abstract
Published analytical methods for moisture and fat analysis of meat and meat products and reviews of the methodology are surveyed. The methods are briefly described and characteristics such as time required for an analysis, accuracy, and precision are given. The discussion of instrumental methods includes methods which have not been fully developed for meat but which may become useful. Several of the considerations and limitations that are involved in moisture and fat analysis of meat are discussed. From the large number of moisture, fat, and combined methods available, the most promising were selected for a close inspection and compiled in two tables of data. The most useful rapid methods for meat industry quality control are the following: For moisture determination, high temperature mechanical convection oven drying, hot plate drying, moisture balance, and azeotropic distillation methods have the most advantages. For fat content determination, the modified Babcock procedures, X-ray transmission, specific gravity of heptane extracts, and determination of fat in the extract from azeotropic moisture analysis (a combined method) offer the most advantages.
Gas Chromatographic Determination of Brominated Sesame Oil in Orange Drinks: Collaborative Study
Authors: Conacher H B S 
Published: February 2020

Abstract
A gas-liquid chromatographic method for the determination of brominated vegetable oils in soft drinks was collaboratively studied, using a commercial orange drink spiked with known amounts of brominated sesame oil. Initial results based on calculations involving total peak area measurement were considered erroneously high, since drink components coeluted with the C16 and C18 methyl esters, especially at low levels of brominated oil. A modified calculation, based only on brominated ester content, showed recovery values (6 collaborators) of 94.6, 95.3, and 96.0% for drinks containing 3.10, 5.22, and 10.66 mg/10 fluid oz., respectively, with corresponding standard deviation values of 0.40, 0.46, and 0.64. The method with the modified calculation incorporated has been adopted as official first action.
Nitrate, Nitrite, and Dimethylnitrosamine in Cured Meat Products
Authors: Panalaks Thayil , Iyengar Jagannath R , Sen Nrisinha P 
Published: February 2020

Abstract
Nitrate, nitrite, and dimethylnitrosamine (DMN) were determined in 197 samples of various kinds of meat products. Nitrate and nitrite were determined by the method of Kamm et al. (1965), and DMN was estimated semiquantitatively by a GLC method using a Coulson electrolytic conductivity detector (pyrolytic mode). The average levels of nitrate and nitrite were 181 ppm (range, 0–3467 ppm) and 28 ppm (range, 0–252 ppm), respectively. Trace amounts (2–12 ppb) of DMN were present in 57 samples; others were negative. As no mass spectrometric confirmation of the identity of DMN was carried out, the results should be considered as only tentative and not as an absolute proof of the presence of DMN. Except in a few types of meat products, the concentrations of nitrate or nitrite did not correlate with that of DMN detected in the samples.
Collaborative Study of a Method for the Extraction of Light Filth from Prepared Horseradish
Authors: Gecan John S , Brickey Paris M 
Published: February 2020

Abstract
A method has been developed for the extraction of light filth from prepared horseradish. The method involves a direct flotation from 40% isopropanol with a mineral oil-n-heptane mixture. Collaborative study showed the method to be rapid and easy to perform, and to yield good recoveries and clean extraction papers. The method has been adopted as official first action.
Collaborative Study of the Extraction of Light Filth from Canned Whole and Cream Style Corn
Authors: Dent Russell G 
Published: February 2020

Abstract
An improved method has been developed for canned whole and cream style corn to replace 40.104. The proposed method is unique because the microscopic and macroscopic examinations can be conducted almost concurrently; in the official method the macroscopic examination is dependent upon completion of the microscopic examination. The proposed method is shorter and it eliminates the use of viscous castor oil by specifying extraction in a percolator with paraffin oil from hot 40% isopropanol. Glassware is easily cleaned up after percolator cycles with isopropanol and water rinses. The proposed method yielded improved recoveries of insect and rodent filth spike elements. The method has been adopted as official first action.
Method for Determining Direction of Insect Boring Through Food Packaging Materials
Authors: Brickey Paris M , Gecan John S , Rothschild Albert 
Published: February 2020

Abstract
Insect chewing on food packaging materials has been characterized in order to differentiate between entrance and exit bore holes. The characteristics specific to various types of packaging are presented as a method in the form of a descriptive “key” that permits determination of the direction of boring. A collaborative study of the method resulted in 92% correct determinations of boring direction. The method has been adopted as official first action.
Differentiating Nonaqueous Titration of Mixtures Containing Acetaminophen and Salicylamide
Authors: Blake Martin I , Shumaker Linda B 
Published: February 2020

Abstract
A differentiating nonaqueous titration procedure is described for the determination of mixtures of acetaminophen and salicylamide. Tetrabutylammonium hydroxide is the titrant and a Fisher titrimeter equipped with a calomel-glass electrode system is used. The technique is applied to the individual components, synthetic mixtures, and complex dosage forms.
Nuclear Magnetic Resonance Analysis of Pharmaceuticals. IX. Methenamine and Methenamine Mandelate in Tablets
Authors: Turczan John W , Goldwitz Bruce A 
Published: February 2020

Abstract
An NMR procedure is described by which methenamine and mandelic acid are simultaneously determined in methenamine and methenamine mandelate tablets. Maleic acid was chosen as the internal standard and dimethylformamide-acetone-acetonitrile (10+25+65) as the solvent. The solvent system was selected to resolve the problems of solubility of methenamine and its salt with mandelic acid, overlapping of the resonance signals of the components, and potential decomposition of methenamine. Known standard and commercial preparations were analyzed and the results were compared to those of official USP and NF procedures. The NMR technique, when applied to the determination of methenamine and methenamine mandelate in tablets, is rapid, simple, and specific and can provide an assay with an accuracy of 1–2%.
Collaborative Study of a Semiautomated Method for the Analysis of Sodium Warfarin and Dicumarol Tablets
Authors: Kolinski Richard E 
Published: February 2020

Abstract
A semiautomated extraction and UV determination for sodium warfarin and dicumarol tablets was collaboratively studied by 7 laboratories. Collaborators were supplied with 4 composites of tablets of different dosage levels (3 sodium warfarin composites and 1 dicumarol composite). Results agreed well with the USP method. For sodium warfarin, coefficients of variation ranged from 0.35 to 2.10%. For dicumarol, coefficients of variation ranged from 0.39 to 2.19%. The method has been adopted as official first action.
Collaborative Study of the Quantitative Determination of Ethanol by Gas-Solid Chromatography
Authors: Martin Glenn E , Figert Donald M 
Published: February 2020

Abstract
The determination of ethanol by gas-solid chromatography was collaboratively studied for nonbeverage alcohol samples by 10 collaborators representing 6 laboratories. In one sample, the alcohol was determined by pycnometer, hydrometer, fluid densitometer, and gas-solid chromatography and the results obtained by these procedures compare favorably. The standard deviation for the 7 samples range between 0.133 and 1.311. This method is simple and fast, and the interference from other compounds is essentially eliminated. The proposed procedure for the quantitative determination of ethanol has been adopted as official first action.