bluuebunny/crossref_metadata_2025_split huggingface dataset:
Collaborative Study of the Thermistor Cryoscopic Method for the Determination of the Freezing Point Value of Milk
Authors: Henningson R W 
Published: February 2020

Abstract
Data from 19 collaborators for two sample pairs were used to estimate the precision and systematic error of the thermistor cryoscopic method for determining the freezing point value of milk. Precision was greater for the milks (0.0015°) than for the standards (0.004°). The systematic error was estimated to be 0.0033°. The standard deviation for interlaboratory individual determinations was estimated to be 0.0049°.
Determination of Choline in Feeds
Authors: Roberts Talmadge , Fritz James C 
Published: February 2020

Abstract
The amount of choline in feedstuffs and mixed diets was determined by chemical, microbiological, and biological methods and the results were compared. The results of the chemical assay, based on the Reineckate method, varied according to the extraction procedure. The results of the microbiological method, using the Neurospora crassa mutant, seemed high, and the results of the biological chick assay were closer to the calculated values. Calculated or published values for choline chloride in a chick starter feed, degermed yellow corn meal, dehulled soybean meal, dried brewers yeast, and dried torula yeast were 1.93, 0.44, 2.86, 3.63, and 2.75 mg/g, respectively. Chemical results by the rapid Reineckate method were 1.66—2.10, 0.40-0.48, 1.78-2.14, 0.38, and 0.49-0.60 mg/g, respectively. Results were 2.00, 0.45, 3.40, 4.97, and 4.50 mg/g, respectively, by the longer Engel method. The microbiological and biological assay results were 2.28, 0.65, 4.01, 4.78, and 7.60; and 2.07, 0.55, 2.93, 4.69, and 5.98 mg/g, respectively. Further study is recommended.
Recommended Changes in the Method for Detection and Identification of Salmonella in Egg Products
Authors: Poelma Paul L 
Published: February 2020

Abstract
Changes are recommended in the AOAC method for detection and identification of salmonellae in egg products to prevent the analyst from discarding atypical cultures; certain TSI agar cultures are tested with lysine iron agar before discarding them as not salmonellae. These changes were necessary since several investigators have isolated lactose-fermenting salmonellae from clinical cases and foods, and sucrose-fermenting salmonellae have also been reported.
Determination of Hydroxybenzoates and Benzoates in Foods
Authors: Lewis M H 
Published: February 2020

Abstract
A successful collaborative study was made on the determination of benzoates in solid foods, using the official, first action method for benzoates in liquid and semisolid foods. The method combines steam distillation, TLC, and UV spectroscopy. Recovery data ranged from 94 to 120%. An attempt to separate the parabens by GLC was successful but further work is needed for the quantitative determination of these compounds.
A New Flash Injector for Gas Chromatography of Organophosphorus Insecticides
Authors: Solomon J 
Published: February 2020

Abstract
A new "flash injector" is described which features the removal of solvent from organophosphorus insecticide solutions prior to gas chromatography, using the stacked flame ionization detector. A micro-thin film of sample is deposited on glass wool for instantaneous vaporization in the injection port by syringe-injecting an aliquot of sample into a Pyrex glass wool plug contained in a specially designed Pyrex glass tube that fits the injection port. After pre-vaporization of the solvent, flash injection is completed by inserting and sealing the tube in the injection port by a mechanical flash injector. The method prodvices good chromatographic peaks and resolution, eliminates solvent peaks and interferences, improves reproducibility, prolongs column life, eliminates the use of septums, and requires little or no cleanup of extracts. Errors due to blow-by in the syringe, caused by injection against high port pressures, are eliminated. Injections larger than 5 /il can be used to facilitate detection of organophosphorus residues in low concentrations without extinguishing the detector flames.
Gel Permeation Cleanup for Malathion in Wheat, Using a Non-Ionic, Cross-Linked Polystyrene Polymer
Authors: Aker Norman L , Schanderl Sigmund H , Leeling Norman C 
Published: February 2020

Abstract
A gel permeation method, using non-ionic, cross-linked polystyrene beads (Bio-Beads), has been utilized for the separation of malathion from wheat samples. Elution patterns, using malathion-fortified wheat extracts, established that interfering materials were eluted before malathion. Extracts containing up to 1 mg malathion were successfully cleaned up at flow rates of 34—40 ml/hr; preliminary results indicate that flow rates up to 125 ml/hr do not adversely affect separation. Recoveries of malathion from fortified wheat extracts ranged from 90 to 112% for 10 to 1000 jug quantities. Preliminary study indicated that the cleanup was adequate when mixtures of other insecticides were included in wheat extracts containing malathion. The use of a column of non-ionic, cross-linked polystyrene beads for extract cleanup is simple and economical, since no apparent change in column performance occurs after repeated use.
Zebra Fish Eggs and Larvae as Aflatoxin Bioassay Test Organisms
Authors: Abedi Z H , Mckinley W P 
Published: February 2020

Abstract
Aflatoxin B1 is acutely toxic to embryos and larvae of zebra fish, Brachydanio rerio (Hamilton-Buchanan). These organisms are sensitive to sub-microgram quantities of the toxin and can be used as bioassay test organisms. The larval response is easier to measure than embryonic response, and a standard dosage-mortality curve for the larvae can be developed in 33 hr. As an aflatoxin bioassay test organism, the larvae of zebra fish have several advantages over other test organisms, including ducklings, embryos, and tissue cultures. They require no special skill or equipment and can be obtained easily in the laboratory throughout the year.
Growth and Production of Aflatoxins by Aspergillus flavus on Red Pepper {Capsicum frutescens L)
Authors: Schindler A F , Eisenberg W V 
Published: February 2020

Abstract
Aspergillus flavus grew on a substrate of crushed and fresh red pepper (Capsicum frutescens) and produced anatoxins B1 and G1. In addition, there was a shift in the ratio of aflatoxins B1 to G1 as compared to the ratio of these aflatoxins when grown on a Wort agar substrate. The increase in the proportionate amount of aflatoxin G1 to aflatoxin B1 extracted from the crushed red pepper was statistically significant at the 0.1% level.
Determination of Heavy Metals in Wines by Atomic Absorption Spectrophotometry
Authors: Měranger J C , Somers E 
Published: February 2020

Abstract
The effect of alcohol and sugar concentration on the atomic absorption analysis of copper, zinc, nickel, chromium, lead, cadmium, and cobalt has been investigated. Sugar reduced the sensitivity of analysis but could be compensated for by using the method of additions. Interference from alcohol was avoided by introducing an evaporation stage, and the concentration of the above cations was determined by direct aspiration in 24 native and imported wines.
The High Resolution NMR Spectra of Pesticides. I. Organophosphorus Pesticides
Authors: Keith Lawrence H , Garrison Arthur W , Alford Ann L 
Published: February 2020

Abstract
A description of the 100 MHz nuclear magnetic resonance spectra of forty organophosphorus pesticides is presented as an identification aid and reference source. Chemical shifts and coupling constants are presented in tabular form, along with a discussion and figures of the more complex or unusual spectra. Tables of trends in chemical shifts and coupling constants as related to structure are included. Homonuclear spin decoupling, integration, protonation with trifluoracetic acid, D20 exchange, temperature, solvent and dilution effects, and supplemental 60 MHz spectra all were employed in correlating the spectra with the structures of the corresponding molecules. Interesting phenomena observed include long-range phosphorus to hydrogen coupling through four and five bonds, chemical nonequivalence of methylene groups and methyl groups in (CH3CH20)2P and (CH30)2P moieties, differences in the spectra of the cis and trans isomers of two pesticides due to anisotropic effects of their carbonyl groups, and magnetic nonequivalence of geminal methylene protons adjacent to an asymmetric carbon atom
Sodium Methylate Treatment of Cleaned Up Plant Extracts in Confirmation of Some Pesticide Residues By Gas-Liquid and Thin Layer Chromatography
Authors: Mendoza C E , Wales P J , Mcleod H A , Mckinley W P 
Published: February 2020

Abstract
A rapid procedure that involves GLC-EC and TLC analyses of plant extracts 5 min after treatment with sodium methylate is described for the qualitative confirmation of some pesticide residues. Plant extracts are cleaned up by elution through a carboncellulose column before treatment. The compounds studied were aldrin, captan, carbophenothion, p,p'-DDD, de-hydrochlorinated p,p-DDD, p,p'-DDE, o,p -DDT, p,p -DDT, Diazinon, dieldrin, disulfoton, heptachlor, heptachlor epoxide, malathion, methoxychlor, de-hydrochlorinated methoxychlor, mevinphos, and parathion. The pesticides added to beet, lettuce, pineapple, potato, and wheat eluates were reliably confirmed by GLC-EC or TLC after sodium methylate treatment. The procedure could be used to confirm only some of the pesticides added to extracts of apples, carrots, cauliflower, grapes, and peas because of components in these samples that gave interfering peaks
Thin Layer Chromatography of Organophosphorus Insecticides with Several Adsorbents and Ternary Solvent Systems
Authors: Getz Melvix E , Wheeler Helen G 
Published: February 2020

Abstract
Forty-two organophosphorus insecticides were chromatographed on binder-free thin layer plates prepared from silica gel, aluminum oxide, and magnesium silicate. Five ternary solvent systems were used for the development and three selective chromogenic sprays for the identification of the migrated spots
Ultraviolet Spectra-Structure Correlations of Some Compounds of Pharmaceutical Interest: Review of General Principles
Authors: Furman William B 
Published: February 2020

Abstract
A brief survey of ultraviolet spectrastructure data is presented, oriented specifically toward the pharmaceutical chemist. Chromophores derived from benzene, phenol, pyridine, barbituric acid, xanthine, and phenothiazine are discussed in terms of wavelength of maximum absorbance and concentrations required for quantitative analysis
Determination of Small Bone Particles in Meat
Authors: Hill Robert M , Hites B D 
Published: February 2020

Abstract
Very small particles of bone can be separated from ground meats and meat products by the following procedure: The bulk of the meat is solubilized by digestion with papain and the bone is separated from the other nondigestible material according to its ability to settle in a carbon tetrachloride: acetone mixture. Turkey samples with widely varying bone content were analyzed, with good agreement between duplicate samples.
DDT-Type Compounds: Separation and Identification by a System Combining Thin Layer Chromatography, Gas Chromatography, and Infrared Spectroscopy
Authors: Abou-Donia M B , Menzel D B 
Published: February 2020

Abstract
Infrared spectroscopy, in combination with TLC and GLC, offers an effective technique for isolation, separation, and identification of DDT-type compounds. Rf values for DDT and 13 other compounds, most of which have been reported as DDT breakdown products, have been determined in 27 solvent systems, using TLC techniques. Three columns, in combination with the electron capture detector, have been experimentally studied to analyze the 13 DDT-like compounds. The positions and intensities of the infrared bands of the 14 compounds have been measured in KBr. The variations of these measurements have been discussed in relation to the structural changes of DDT-type compounds.
Determination of Cyclamates (Sodium and Calcium Salts) in Canned Fruits
Authors: Johnson D E , Nunn H B 
Published: February 2020

Abstract
A method for determining calcium or sodium cyclaniate in canned fruits and fruit products has been developed. The cyclamate salt in a homogenized portion of fruit is hydrolyzed to cyclohexylamine in the presence of hydrochloric acid at 125°C and 15 psi. The cyclohexylamine is extracted into chloroform and reacts with ethanolic p-quinone to produce 2-(cyclohexylamine)-l,4-benzoquinone, which is determined spectrophotometrically at 493 mµ. Sucrose and saccharin do not interfere. Eleven collaborators tested the method on canned pears, peaches, pineapple, and grapefruit. Each fruit was fortified at two different levels with sodium cyclamate. The average recovery of both levels of cyclamate salt in all four fruits was 98.7%. Each collaborator also tested the method on a can of commercially canned dietary peach pie filling. The results were good, and the method is recommended for adoption as official, first action.
Method for Evaluating the Potential Availability of Water-Insoluble Nitrogen Sources in Mixed Fertilizers
Authors: Katz Stanley E , Fassbender Carol A 
Published: February 2020

Abstract
A method was developed for the estimation of potential availability of waterinsoluble nitrogen sources in fertilizer based upon solution biodegradability procedures, i.e., water-insoluble nitrogen sources are degraded in the soil by microorganisms, making the nitrogen available to both plants and organisms. As the degradation of the nitrogen source proceeds in solution, the medium becomes turbid and the intensity of the turbidity reflects the degree of degradation. Eleven water-insoluble nitrogen sources and four commercial fertilizers were studied. Materials studied included representatives of plant, animal, marine, and synthetic origin. A parameter designated as the biodegradability index was proposed to better define water-insoluble nitrogen sources.
Determination of the Volume Weights, Water-Holding Capacity, and Air Capacity of Water-Saturated Peat Materials
Authors: Thorpe Virginia A 
Published: February 2020

Abstract
To evaluate the aeration, water penetration, and water retention properties of peat under field conditions of water saturation, the method for determining the volume weight, water-holding capacity, and air capacity of water-saturated peat materials has been proposed and studied collaboratively. Although statistical treatment of the collaborative results indicates a satisfactory degree of precision for the products under consideration, correlation of the results with data indicates that small changes in the “packing” technique of the method would be desirable. The proposed method, as amended, is recommended for adoption as official, first action.
Collaborative Study of Infrared Anatysis of Dicamba
Authors: Malina Marshall 
Published: February 2020

Abstract
A collaborative study was conducted on an infrared method for the analysis of dicamba and its liquid formulations. Each sample was dissolved directly and submitted to infrared analysis, and its absorbance was compared to a reference standard. Results from 13 collaborating laboratories showed excellent precision, with a coefficient of variation of 0.017. Six laboratories participated in the study on liquid formulations, and results also showed excellent precision, with a coefficient of variation of 0.021. This method is recommended for adoption as official, first action.
Collaborative Study of the Determination of Morphine in Paregoric
Authors: Smith Edward 
Published: February 2020

Abstract
A partition chromatographic method for the determination of morphine in paregoric and other opium preparations was subjected to collaborative study. The morphine is separated from associated opium alkaloids by successive elution through consecutive acidic and alkaline columns and is measured by UV absorbance. The isolated morphine was shown to have a high degree of purity. The method is rapid and the results of the collaborative study show good precision and accuracy. The method is recommended for adoption as official, first action.
Lysergic Acid Diethylamide: Review and Collaborative Study
Authors: Look James 
Published: February 2020

Abstract
A method for identification and determination of lysergic acid diethylamide (LSD) was studied collaboratively by 11 collaborators on three samples prepared by the Associate Referee. The presumptive test is a valuable tool for rapid preliminary examination. Racemization of the LSD adds further to its identification by paper chromatography. Assay recovery, based on Sandoz LSD-25 reference standard, was 98.0%. Recovery by the same assay, but based on Ergonovine Maleate USP Reference Standard, was 96.5%. The method is recommended for adoption as official, first action.
Analytical Profiles of Sorghum Cane and Sugar Cane Sirups
Authors: Johnson Arthur R , Sturdivant Arthur T 
Published: February 2020

Abstract
Authentic samples of sorghum sirup and cane sirup have heen ohtained and analyzed for total solids, reducing sugars, sucrose, ash, Winton lead number, and polarization at 87°C. These analytical data may he used as guides in establishing purity of the sorghum cane and sugar cane sirups. Because of the similarity and the overlapping ranges of values, the sirups cannot be readily distinguished in blends
Indoxyl Acetate Spray Reagent for Fluorogenic Detection of Cholinesterase Inhibitors in Environmental Samples
Authors: Schutzmann R L , Barthel W F 
Published: February 2020

Abstract
A cholinesterase inhibition method to detect ihionophosphates (P=S compounds) and their oxygen analogs (P=O) by twodimensional thin layer chromatography is described. Environmental samples are cleaned up on Florex columns and spotted on silica gel thin layer plates. Plates are developed in solvent mixtures of opposite polarity, then sprayed with an enzyme solution and indoxyl acetate. Submicrogram sensitivity is achieved by fluorogenic and chromogenic reaction. Some compounds give characteristic colored reaction products.
GLC Determination of Residues of Disulfoton, Oxydemetonmethyl, and Their Metabolites in Tobacco Plants
Authors: Bowman M C , Beroza Morton , Gentry C R 
Published: February 2020

Abstract
Residues of disulfoton and five of its metabolites on disulfoton-treated tobacco plants were analyzed as follows: Plant extracts were separated into three fractions by liquid chromatograpliy and an aliquot of each was analyzed by GLC, using a flame photometric phosphorus detector. The tobacco caused no background interference in the GLC analysis. Recoveries of five of the six compounds from plants fortified at the 1 ppm level were 88 to 100%; the sixth was unstable in tobacco and its oxidation products were detected. GLC response was linear up to the 250 ng level and the sensitivity was 0,01 to 0.04 ppm. The general procedure was also successfully applied to oxydemetonmethyl and its sulfone, which are chemically similar to two of the disulfoton metabolites.
Comparison of Four Extraction and Cleanup Procedures for Chlorinated Pesticide Residues in Eggs
Authors: Wessel John R 
Published: February 2020

Abstract
The extraction efficiencies, based on the amount of pesticide removed by an exhaustive extraction, of four procedures were compared for effectiveness in removal of chlorinated pesticide residues incurred in eggs from hens fed lindane, DDE, DDT, heptachlor epoxide, dieldrin, and endrin. Acetonitrile, as used in the Mills, Onley, and Gaither method for nonfatty foods, yielded results equivalent to the exhaustive extraction, the double acetonitrile extraction by blending, and the Sawyer rapid method for eggs. Two types of Florisil columns, a split layer and a single layer column, were compared for cleanup efficiency of egg extracts from the Sawyer and the Mills et al. methods. Results of these studies indicate that the Mills et al. rapid method is applicable for the analysis of chlorinated pesticide residues in eggs at a level of 0.01 ppm.
Extraction and Gas-Liquid Chromatographic Determination of Vernolate in Soil
Authors: Hermanson H P , Siewierski Marie , Helrich K 
Published: February 2020

Abstract
A gas-liquid chromatographic system using flame photometric detection was developed for the separation and measurement of residue quantities of vernolate and 1-propanethiol in soil. With a 3% Apiezon L on Chromosorb G column, the limit of detection was 0.003 μg for either compound.
Method for the Extraction of Light Filth from Seedless and Seeded Raisins
Authors: Gecan John S , Brickey Paris M 
Published: February 2020

Abstract
A method has been developed for the extraction of light filth from seeded and seedless raisins. Raisins are chloroform defatted, rehydrated in water, wet sieved, and extracted in a trap flask. Collaborative study resulted in reproducible recoveries and clean filter papers. This method is recommended for adoption as official first action.
TLC Determination of Uncombined 2-Naphthol-6-Sulfonic Acid (Sodium Salt) (Schaeffer Salt) in Color Additives
Authors: Moten Lueangier , Kottemann Christine 
Published: February 2020

Abstract
A thin layer chromatographic method is presented for determining uncombined sodium salt of 2-naphtliol-6-sulfonic acid (Schaeffer salt) in Ext. D&C Green No. 1. A direct fluorometric measurement may also be used to determine Schaeffer salt in Ext. D&C Green No. 1 and in FD&C Yellow No. 6. Uncombined Schaeffer salt in commercial samples of FD&C Yellow No. 6 varied from 0 to 0.5%; no samples of External D&C Green No. 1 were found to contain &gt;0.1% of uncombined Schaeffer salt.
Analysis of Cocoa Beans for Aflatoxins
Authors: Scott P M 
Published: February 2020

Abstract
The CB method for the analysis of peanut products for aflatoxins was modified to overcome the prohlem of an insoluble final residue when applied to cocoa: a 25% silver nitrate solution is used as the aqueous phase in the extraction procedure and the chloroform extract is reshaken with this reagent before column chromatography on silica gel. Good backgrounds arc obtained on TLC plates when the method is applied to powdered cocoa beans initially defatted with Ji-hexane. Recoveries of added aflatoxins are satisfactory (80-90%).
Quantitative Method for the Estimation of Aflatoxins in Peanuts and Peanut Products
Authors: Mayura K , Sreenivasamurthy V 
Published: February 2020

Abstract
A quantitative method for the estimation of four aflatoxins, based on chromatographic separations and selective destruction of B1 and G1 by nitric acid, has been developed. To enhance the specificity of the method, a sample blank is determined and is used to correct the values for nonspecific interfering substances.
Detection of Enzymatic Chillproofing Agents in Beer
Authors: Stone Irwin 
Published: February 2020

Abstract
A recently published ASBC method for the qualitative detection or semiquantitative determination of traces of proteolytic enzymes in beer is presented for adoption as official first action by the AOAC. Five other new methods of the ASBC are expected to have early publication. Eleven technical subcommittees are conducting studies.
Automated Determination of Zoalene in Feeds
Authors: Christopherson Howard L 
Published: February 2020

Abstract
Elimination of 5 steps (a quantitative wash, dilution to 100 nil, spiking an aliquot, evaporation to dryness, and dissolution in dimcthylformamide) in the official AOAC method for Zoalene in feeds and automation of the color reaction with cthylenediaminc using Technicon equipment has increased speed and precision several fold without significantly changing the chemistry of the AOAC method. A sampling rate of 80 analyses per hour with nearly steady state peak heights, good resolution hetween peaks, and low mixing noise was achieved hy using modified fittings and compressed gas for solution segmentation. A differential colorimeter provides automatic correction for feed blanks.