bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of Compounds Related to Vanillin in Vanilla Extracts
Authors: Smith D Morison 
Published: February 2020

Abstract
A method has been developed for the estimation of the quantities of vanillic acid, p-hydroxybenzoic acid, and p-hydroxybenzaldehyde in vanilla extracts. This method separates these compounds from each other and from vanillin by two-dimensional paper chromatography. An estimate of the quantity of each of these compounds is obtained by measuring the area of the colored spot produced on reacting the compounds with chromogenic reagents. The vanillin content was also determined by two different methods. Vanilla planifolia was found to have an unidentified phenolic component not present in V. tahitensis. The Tahiti vanillas contained over twice as much p-hydroxybenzoic acid as any other vanilla extracts.
Quantitative Infrared Determination of the Isomers of Ethylbenzylaniline Sulfonic Acid
Authors: Wilson Clifton H , Dolinsky Meyer 
Published: February 2020

Abstract
A simple analytical procedure is described for determining the three isomers of N-ethyl-N-phenyl benzylamine sulfonic acid. The sulfonic acids are converted to their LA-2 resin salts, dissolved in carbon disulfide, and analyzed by infrared spectrophotometry.
Microbiological Assay of Low Chlortetracycline Concentrations in Animal Feeds
Authors: Abbey Anthony , Hewel David B 
Published: February 2020

Abstract
Satisfactory microbiological values were obtained for animal feeds containing low levels of cblortetracycline (CTC), 5.0–40g CTC/ton. Results were comparable when calculated against both compensating CTC standard curves prepared from blank feed extracts and laboratory-inactivated CTC feed extracts. The inactivation of CTC in animal feed extracts by 5.25% sodium hypochlorite solution and heat was investigated, and it appeared to offer a convenient alternative for preparing compensating CTC standard curves.
Qualitative Determination of Sulfa Drugs in Medicated Feeds by Thin-Layer Chromatography
Authors: Alexander Leland R , Stanley Eugene R 
Published: February 2020

Abstract
Sulfacetamide, sulfadiazine, sulfaquinoxaline, sulfamerazine, sulfamethoxypyridazine, sulfamethazine, and sulfanilamide are extracted from a medicated feed with acetone. The acetone is evaporated, the residue is taken up in basic solution, and the interfering material is extracted from the basic solution with chloroform. The basic solution is then made acidic and evaporated to dryness. The sulfas are extracted from the residue with acetone, separated, and identified by thin-layer chromatography. Methanol-chloroform (3 + 7) is used as mobile solvent; an acidic solution of dimethylaminobenzaldehyde in ethanol is used as the chromogenic agent. The method easily detects and identifies 1 μg of the individual sulfas.
Ethopabate in Feeds
Authors: Szalkowski C R 
Published: February 2020

Abstract
A collaborative study was completed on a method for the determination of ethopabate. Ethopabate is extracted from the feed with 50% methanol at room temperature, and separated from amines by chloroform extraction. The chloroform extract is washed with sodium carbonate solution to remove interfering drugs, if present. Chloroform is removed by evaporation, and the ethopabate residue is hydrolyzed with HCI to the free amine, which is diazotized and coupled. The colored compound is extracted and measured at 555 mμ against pure reference standard ethopabate. Unmedicated commercial poultry feeds showed an apparent ethopabate content of 0.2–0.5 ppm. Recoveries from these same feeds after medication with ethopabate ranged from 96 to 105%. This assay method is suitable for determining ethopabate down to 2 ppm and is recommended for adoption as official, first action, for all levels of ethopabate.
Spectrophotometric Determination of Thiabendazole in Feeds
Authors: Szalkowski C R , Kanora J 
Published: February 2020

Abstract
An improved method has been developed for thiabendazole in feeds. Thiabendazole is extracted from the feed with 0.2N HCl in 50% methanol; interfering substances are removed by making the extract alkaline and extracting into chloroform. The thiabendazole is re-extracted with dilute HCl; the solution is reduced with zinc dust in the presence of p-phenylenediamine to form a hydrogen sulfide complex. After subsequent oxidation with ferric solution to form a thiazine dye, the dye is extracted into n-butanol and measured at 605 mμ. More than 30 commercial unmedicated cattle and swine feeds show an apparent thiabendazole content of 0.00006–0.00044%. Recoveries on feeds made to contain 0.0025–10.0% thiabendazole ranged from 97.6 to 106.6%, with a coefficient of variation of 2.44%. In studies of 30 other drugs added to feeds, only nithiazide, Enheptin, and sulfathiazole interfere. Many variables involved in the color development were studied. The method gives the most accurate and reproducible results on solutions containing 0.2–2.0 μg thiabendazole/ml.
Further Studies on the Yeast and Enzyme Methods for Determining Lactose in Meat Products Containing Corn Sirup
Authors: Hankin Lester , Wickroski Alphonse F 
Published: February 2020

Abstract
Further comparative studies were conducted on lactose determination in meat products by the enzyme method and the AOAC yeast method. Inflated values for lactose in meat products result from the AOAC yeast method on meat samples containing corn sirup solids and nonfat dry milk. Quantitative data indicate that maltose is primarily responsible for the high values, and that dextrin interference is slight. The average difference between the yeast and enzyme methods for commercial samples declaring both corn sirup and nonfat dry milk was 0.27% lactose. The enzyme method appears useful for determining lactose in meat products containing corn sirup.
Infrared Assay for Santonin in Tablets
Authors: Biesemeyer Mae E 
Published: February 2020

Abstract
A quantitative infrared procedure for the determination of santonin and/or santonin in combination with calomel in tablets has been studied collaboratively. Santonin is extracted with CHCl3 from an ammoniacal aqueous phase and evaporated to dryness. The residue is dissolved in CS2 and baseline absorbances are determined relative to CS2 at a maximum of 9.75μ, with the baseline between minima of 9.6 and 9.95μ. This method was adopted as official, first action.
Separation and Identification of Sodium Salts of Acetic, Propionic, Butyric, and Valeric Acids by Paper Chromatography
Authors: Young James A , Schwartzman George , Melton Anna L 
Published: February 2020

Abstract
A method has been developed to confirm the identity of volatile fatty acids after they have been steam distilled, separated by a silicic acid column, and titrated with NaOH. The method works equally well for the detection of propionates in bread products. This paper reports a second collaborative study with a modified mobile solvent: two volumes of acetone added to equal volumes of n-butanol, tertiary butanol, and concentrated NH3. This solvent system gives a more distinct separation of the acid spots, the spots remain stable longer, and the time required for the paper to develop is reduced to 2.5 hours. Six laboratories and eight collaborators participated in the study. The method was adopted as official, first action for identifying the sodium salts of the C2–C5 acids and as a qualitative test for propionates in bread products.
Studies on an In Vitro Method for Determining Tuberculocidal Activity With Disinfectants
Authors: Ortenzio L F 
Published: February 2020

Abstract
An in vitro method for determining tuberculocidal activity of disinfectants, composed of a presumptive procedure using Mycobacterium smegmatis with a 12-day incubation period and a confirmative procedure using Mycobacterium tuberculosis with a 60-day incubation period, is given in detail. Collaborative results on the confirmative procedure by seven laboratories establish a reasonable degree of precision and show clearly that this part of the test is capable of detecting possible errors in the analysis of data developed in the presumptive part of the method. The method is recommended for adoption as official, first action.
Determination of Residual Germicidal Activity in Swimming Pool Water
Authors: Ortenzio L F 
Published: February 2020

Abstract
Collaborative results on the standard test for the efficiency of germicides in disinfecting swimming pool water (This Journal, 47, 541 (1964)) showed a reasonable degree of precision. Variations in the standard sodium hypochlorite solution and unknown sample are discussed. The method is recommended for adoption as official, first action.
Rapid Procedure for Carbaryl Residues: Modification of the Official Colorimetric Method
Authors: Benson Walter R , Finocchiaro Josephine M 
Published: February 2020

Abstract
A modification of the official colorimetric method for carbaryl eliminates the need for special equipment and shortens the time of analysis. Recoveries from eight crops at about 10 ppm levels ranged from 84 to 106%. Crop blanks, except for cabbage, averaged about 0.2 ppm.
Qualitative Determination of Syringaldehyde and Dihydroconiferyl Alcohol in Maple Sirup
Authors: Underwood J C , Filipic V J 
Published: February 2020

Abstract
The combined amount of syringaldehyde and dihydroconiferyl alcohol in maple sirup was determined by extracting the sirup with methylene chloride, isolating the compounds by GLC (SE-30 column), and comparing the height of the single peak representing the two compounds with a standard of syringaldehyde. The procedure accounts for 97–98% of the SA-DHCA in the sirup with a standard deviation of ± 4% of the value obtained. Two samples of sirup were found to contain 5 and 8 ppm SA-DHCA.
Antioxidants (BHA and BHT) in Breakfast Cereals
Authors: Takahashi David M 
Published: February 2020

Abstract
Antioxidants (BHA and BHT) in different types of breakfast cereals were studied by argon ionization gas chromatography. Samples containing antioxidants were packed into the column, and antioxidants were eluted with redistilled petroleum ether. EIuates were concentrated under N2 and injected into a Barber-Colman Model 10 gas chromatograph. Recoveries ranged from about 92 to 110%. Results obtained by steam distillation-colorimetry methods were erratic. Colorimetric procedures were not free from interferences and could lead to highly erroneous results at the lower ppm levels. The gas chromatographic method is faster, simpler, and more accurate. Collaborative studies on corn and rice ready-to-eat breakfast cereals are recommended.
The EDTA Titration of Calcium and Magnesium
Authors: Steagall Edward F 
Published: February 2020

Abstract
A method is proposed for the EDTA titration of calcium and/or magnesium in pharmaceutical preparations. Five samples simulating these products were analyzed collaboratively by eight analysts in six laboratories. The new method was found to be as precise as, and far less time-consuming than, the present official procedures. The results were easily reproducible by the analyst and the agreement between laboratories was quite good as evidenced by low standard deviations.
Organic Compounds in FD&C Blue No. 1
Authors: Schumacher Robert J 
Published: February 2020

Abstract
Studies show that ethylbenzylaniline sulfonic acid is not present in FD&C Blue No. 1, but that N-ethyl-N-(3-suIfobenzyI)-sulfanilic acid and ortho-, meta-, and parasulfobenzaldehydes are present. The method described is suitable for determination of ESBSA and total sulfobenzaldehydes.
Infrared Techniques Useful in Residue Chemistry
Authors: Blinn Roger C 
Published: February 2020

Abstract
Although infrared spectrophotometry is suitable for the measurement and identification of pesticides and their metabolic products because of its inherent characterizing properties, only recently have techniques and instrumentation become adequate for the difficult requirements of residue chemistry. This paper describes techniques which have been successful for the quantitative measurement and qualitative characterization of micro-quantities of pesticide residues. Because of the nature of residue problems, microtechniques are essential for the successful use of infrared spectrophotometry; these techniques strictly limit the permissible amount of contamination from substrate, reagent, atmosphere, handling, etc. Such techniques are described as well as amounts of material required for reliable infrared data. Quantitative measurements are most reliably made as solutions in long energypath cells, whereas qualitative characterization is best accomplished as micro pellets. Detailed procedures for each of these techniques are described.
Thin Layer Chromatography for Pesticide Residue Analysis
Authors: Kovacs Martin F 
Published: February 2020

Abstract
Thin layer chromatography is a simple, rapid, sensitive, and versatile semiquantitative method which is readily applied to pesticide residue analysis. Its greatest value in residue analysis is as a confirmatory method used in conjunction with gas-liquid chromatography. A new solvent system and micro slide technique for the rapid detection of nanogram quantities of many chlorinated pesticide residues are described.
Paraffins of Cigar Smoke
Authors: Osman S , Barsox J , Dooley C J 
Published: February 2020

Abstract
Column chromatography was used to isolate a fraction from cigar smoke condensate containing a homologous series of normal paraffinic hydrocarbons; the individual hydrocarbons were separated by gas-liquid chromatography and characterized by their infrared spectra, mass spectra, and gas chromatographic behavior. Those compounds identified include the normal paraffins from dodecane to pentacosane. This fraction was isolated from the smoke condensates of four cigar types containing unblended filler tobacco that varied considerably in smoking characteristics. Qualitatively, the four types were identical, but quantitative differences were observed.
Improved Procedure for the Colorimetric Determination of Sulfamethazine in Feeds Containing Aureo SP-250®
Authors: Berg T R , Penrod J Q , Blaylock L G 
Published: February 2020

Abstract
The procedure provided by the manufacturer for the colorimetric determination of sulfamethazine in feeds uses a hot alkaline extraction. This extract is difficult to handle because many feeds form a gel and solubilized protein when heated in the presence of an alkaline solution. Centrifugation does not readily separate these solids. An extraction method utilizing a cold alkaline extraction and a double centrifugation has been developed which yields an extract that can be readily carried through the remaining steps of the analysis. Average recoveries were 104% at the 0.01% level and 106% at the 0.05% level of sulfamethazine.
In addition, a separate study was conducted to determine whether penicillin or aureomycin interfere with the analysis for sulfamethazine. The data indicate that there is no interference.
Chromatographic, Spectrometric, and Irradiation Behavior of Five Carbamate Insecticides
Authors: Eberle D O , Gunther F A 
Published: February 2020

Abstract
A comparison of different analytical techniques for the detection and determination of microgram quantities of five carbamate insecticides is presented: carbaryl, Dimetilan, Isolan, Pyrolan, and Zectran. The insecticides were separated by thin-layer and gas chromatography are quantitatively characterized through combination of these techniques with fluorescence, infrared and ultraviolet spectrometry, and oscillographic polarography. The chemical courses resulting from the influence of natural sunlight and short-wavelength ultraviolet radiation on carbamate insecticides were followed by means of these microanalytical, instrumental methods and are briefly discussed.
Collaborative Study of the Application of Electrometric Titration Techniques in the Volumetric Ammonium Molybdate Method for Phosphorus
Authors: Hoffman W M 
Published: February 2020

Abstract
Results are given on a collaborative study for total phosphorus in which the volumetric ammonium molybdate method (both conventional and formaldehyde titration techniques) was compared with the gravimetric quinoline molybdate method. The conventional titration procedure exhibits a slight positive bias and lacks good precision. The HCHO titration procedure appears as accurate as the quinoline method, but its accuracy is enhanced by the use of a recovery factor. Its precision is better than the other titration procedure but not as good as the quinoline molybdate method. Neither procedure is recommended for adoption as official, first action.
Automatic Flame Photometric Determination of Potassium in Fertilizers. A. Elimination of Anion Exchange Cleanup. B. Using Direct Available P2O5 Extract
Authors: Ussary James P , Gehrke Charles W 
Published: February 2020

Abstract
Three primary standard grade potassium salts, eight Magruder check samples, and 18 commercial fertilizer samples were analyzed by three methods. Primary standards gave an average recovery of 100.0% and an average range of 0.21% K20. Magruder check samples averaged 0.09% K20 higher by the modified flame photometric method than the grand averages of the STPB results on the respective Magruder reports. The modified flame photometric method averaged 0.02% K20 lower than the official flame photometric method and 0.11% K20 higher than the official STPB method on 18 commercial fertilizer samples. The automatic flame photometric method, without anion exchange cleanup, is rapid enough for routine analysis and is as accurate and precise as the AOAC official methods. The method was also applied to the direct available P205 extract. Results on three primary grade potassium salts, seven Magruder check samples, and 13 commercial fertilizer samples were as accurate and precise as the official STPB method.
Activation Analysis of Drugs
Authors: Schlesinger H L , Pro M J , Hoffman C M , Cohan M 
Published: February 2020

Abstract
Activation analysis has been employed to compare and determine the source of manufacture of drugs. The irradiations were carried out with the DASA-TRIGA1 and Naval Research Laboratory nuclear reactors,2 and the induced radionuclides were identified by nondestructive gamma-ray spectrometry. The results show that the technique can be a useful tool for the identification of trace elements which serve to characterize drugs.
Assay of Ascorbic Acid in Pharmaceuticals: A Modified Colorimetric Procedure Using p-Nitroaniline
Authors: Weeks Cora E , Deutsch Mike J 
Published: February 2020

Abstract
The colorimetric procedure by Schmall has been modified by use of diazotized p-nitroaniline as the chromogenic reagent for assaying microgram quantities of ascorbic acid. The volumes have been adjusted so that the entire procedure is conducted in test tubes. Folic acid, choline, inositol, biotin, calcium pantothenate, nicotinic acid and amide, B6 compounds, and ferrous sulfate did not interfere; the thiazole moiety of thiamine gave negligible interference, while the pyrimidine moiety had no effect. The method is not applicable in the presence of p-aminobenzoic acid or cysteine. The results by the p-nitroaniline method were 98–103% of the ascorbic acid found by the dichlorophenol-indophenol method, while the iV-bromosuccinimide method gave 98–105% of the acid as determined by the dye titration.
Extraction of Aflatoxin from Peanut Products by Dialysis
Authors: Jayaraman A , Sreenivasamurthy V , Parpia H A B 
Published: February 2020

Abstract
The dialysis with aqueous methanol of aflatoxin in natural materials has been examined. With the use of aqueous methanol of decreasing strength every two hours, high toxin values are obtained as compared with those obtained by a Soxhlet extraction with methanol. This is possibly because of partial destruction of the toxin by heating in the Soxhlet extraction.
Estimation of Fatty Acid Composition by Gas Chromatography Using Peak Heights and Retention Time
Authors: Bartlet John C , Iverson John L 
Published: February 2020

Abstract
In isothermal gas chromatography, the peak widths have been demonstrated to be a linear function of retention time. For most quantitative purposes, the product of the retention time and peak height can be used for area measurement. Statistical comparison of results obtained by this procedure and by triangulation demonstrate its validity.
Aflatoxin Determination in Seed Meal
Authors: Chen Shui-Chin , Friedman Leo 
Published: February 2020

Abstract
An assay method for aflatoxin B1 in seed meals with a sensitivity limit of &lt;0.02 ppb is described. The sample is extracted with aqueous methanol in a Waring Blendor. The extract is purified by lead acetate precipitation, followed by partition chromatography on Celite, and assayed by comparison of fluorescence intensity with aflatoxin B1 standards on silica gel G-HR thin layer chromatograms. This method successfully eliminates potential interference from a “new blue spot” found in cottonseed meal extracts.
Sugars in Plants: A Preliminary Report on the Use of EDTA in the Munson-Walker Sugar Method
Authors: Potter Earl F , Long Marion C 
Published: February 2020

Abstract
Preliminary studies were conducted on the use of EDTA in the Munson-Walker method for sugar analysis. The method requires less time and attention when the reduced copper is titrated with EDTA instead of sodium thiosulfate. Studies will be continued.
Test for the Determination of Starch in Meat Food Products (Applicable for Estimation of Cereal in Sausages)
Authors: Glover W , Kirschenbaum H , Caldwell A 
Published: February 2020

Abstract
A method has been developed for determining starch in meat food products in which simple sugars are extracted from meat food products with hot 80% ethanol while starch remains. The starch residue is solublized with dilute perchloric acid, readily forms a colored derivative when heated with anthrone-sulfuric acid reagent, and is measured at 630 mμ. It was not necessary to prepare a standard dextrose curve daily. The anthrone-sulfuric acid reagent is good for 3–4 days if kept near 0.0°C.
Nitrodan in Feeds
Authors: Bloom Donald , Gehrt A J 
Published: February 2020

Abstract
The anthelmintic, nitrodan, 3-methyl-5(p-nitrophenyl-azo) rhodanine, is extracted from the feed with dimethyl for mamide: ethanol (1 + 1). The intensely absorbing purple solution formed is separated from the residue by suction filtration through a sintered glass funnel. The filtrate is transferred to a volumetric flask, a small amount of NaOH is added, and the solution is brought to volume, Absorbance is measured at 575 mμ, and the amount of nitrodan present is calculated from a standard curve of known concentrations.
Fatty Acid Composition of White Mustard Seed Oil by Urea Fractionation and Gas-Liquid Chromatography
Authors: Iverson John L 
Published: February 2020

Abstract
The detection of C20 to C26 polyunsaturated fatty acids in a Cruciferae seed oil (white mustard) is possible when these methyl esters are concentrated by urea fractionation. The detection and estimation of fatty acids present in trace amounts (&lt; 0.1%) was simplified by quantitative removal of other fatty acids with similar gas chromatographic retention times. Odd and even chain length di- and tri-unsaturated fatty acids were tentatively identified in white mustard seed oil. A tetraenoic acid, presumably arachidonic acid, was tentatively identified for the first time in a plant lipid of the highest evolutionary level, i.e., angiospermae. More easily extracted “free” lipids have a significantly different fatty acid composition than the more difficult to extract “bound” lipids.