bluuebunny/crossref_metadata_2025_split huggingface dataset:
Atomic Absorption Determination of Total, Inorganic, and Organic Mercury in Blood
Authors: Magos Laszlo , Clarkson Thomas W 
Published: February 2020

Abstract
The atomic absorption method described will determine total mercury and, selectively, inorganic mercury. Organic mercury is measured as the difference between total and inorganic mercury. Lower levels of mercury in samples of human blood (4.1 ng Hg/ml) can be determined with the following precision: total mercury 0.6%, inorganic mercury 8.7%, and organic mercury 5.6%. The mean deviation of 2 sets of analyses, one carried out with the method described in this paper and the other with neutron activation analysis, was 3.6%. Organic (presumably methyl) mercury accounted for 66% of the total mercury in blood in a population with minimum exposure. The red cell-to-plasma ratio of organic (methyl) mercury averaged 13.9 in a population with moderate exposure to mercury in food.
Comparison of Two Extraction Procedures for the Determination of Cholesterol in Dairy Products
Authors: Lacroix Denis E , Feeley Ruth M , Wong Noble P , Alford John A 
Published: February 2020

Abstract
Both the Roese-Gottlieb and silicic acid methods have been used for the extraction of lipids from dairy products. However, the silicic acid method is widely used for the extraction of fatty acids for determination by gas-liquid chromatography. Since it would be advantageous to use this extract for cholesterol determinations, a comparison of the extraction procedures for dairy products was carried out to determine if they gave equivalent values. Cholesterol values were determined by gasliquid chromatography of both extracts. Twenty samples of 6 dairy foods having a milkfat content ranging from 3 to 38% were compared. In every instance the Roese-Gottlieb extracts had higher values for cholesterol than did those from the silicic acid method. With very low fat products the Roese-Gottlieb value was high in 6 of 8 comparisons, but the range among samples was much greater. The Roese-Gottlieb or similar multiple solvent extract methods should be used for all dairy products and any other food product in which part of the cholesterol may be bound to a lipoprotein or otherwise not free in the fat.
Collaborative Study of the Official AOAC Flame Photometric Method for the Determination of Sodium in Fertilizers
Authors: Corominas Luis F 
Published: February 2020

Abstract
The present official final action method, 2.132–2.135 (11 th Ed.), has been compared with the 10th Edition method, 2.117–2.120; the need for ion exchange cleanup before flame photometry was also studied for samples containing 0.1-0.7% sodium. In general, the 11th Edition method produced more precise results; elimination of ion exchange treatment improved values obtained for the standard deviations of the systematic error. These findings are based on 600 individual results reported by 9 laboratories for 4 samples.
Collaborative Study of Analytical Methods for Fluoride in Vegetation: Effects of Individual Techniques on Results
Authors: Jacobson Jay S , Mccune D C 
Published: February 2020

Abstract
A collaborative test of analytical methods and techniques for fluoride in samples of vegetation was carried out by 64 participants and effects on the magnitude and variability of analytical results were assessed. Betweenlaboratory precision (standard deviation) for all data ranged from 2.7 ppm F for the 4 ppm sample to 53 ppm for the 365 ppm sample. Relative standard deviations ranged from 14 to 23% for the samples containing more than 27 ppm F. When data were grouped according to the techniques employed by the collaborators, statistical analyses indicated that many variations in techniques were affecting the analytical results. Both the data and the information supplied by participants support the following conclusions: (1) An explicit set of instructions, specifically designed for samples of vegetation, should be published to reduce the number of variations in analytical procedures used by different laboratories. (2) The semiautomated method, specifically developed for vegetation samples, is a preferred technique because it is simpler and faster than older methods and gives results comparable to those obtained by the Willard-Winter method. (3) The AOAC official final action method for fluoride may be used for the analysis of vegetation if the following modifications are made: Sample size should be 2–10 g dry weight; nickel, Inconel, or platinum crucibles should be used for ashing; 5 g sodium or potassium hydroxide should be used for fusion of ash at 600 °C; and 500 ml distillate should be collected. Results of this collaborative study also suggest that additional studies should be performed to discover why alkaline fixative agents used for ashing affect analytical results and whether simpler and more precise analyses will be obtained by replacing titrimetric or spectrophotometric techniques with the use of the selective ion electrode.
Analysis of Drugs in Pharmaceuticals, Using Simple Extractions and Semiautomated Gas-Liquid Chromatography
Authors: Fricke Fred L 
Published: February 2020

Abstract
A gas-liquid chromatographic method is presented for several drugs, using Dexsil 300 as the liquid phase and an automatic sample injector. Results by this method and the official or other applicable methods are compared. It is demonstrated that content uniformity analyses can be made by using this procedure. The extractions and chromatographic conditions have been standardized to make possible a successful interlaboratory study.
Effect of Maleic Acid on the Ultraviolet Absorption of Some Antihistamine Maleate Salts
Authors: Hamilton James L , Naviasky Helen S , Ment William M 
Published: February 2020

Abstract
Several official compendial monographs contain assay procedures which compare the ultraviolet (UV) absorbance of a sample solution of a mineral acid salt of an antihistamine with that of a standard solution of the antihistamine maleate salt. The recovery data, UV absorbance values, and UV spectra presented show that erroneously low assay results are obtained when UV absorptions (below 280 nm) of antihistamine maleate sample solutions previously extracted from alkaline aqueous media into organic solvents are compared with antihistamine maleate standard sample solutions diluted directly in the same acid medium. Such errors are shown to be caused by the UV absorption properties of the maleic acid moiety.
Analysis of Myo-inositol in Dry Beans by Gas Chromatography of Its Hexaacetate
Authors: Seifert Richard M 
Published: February 2020

Abstract
A method has been developed for the analysis of myo-inositol in California small white beans, pinto beans, and 2 pinto bean flake products by gas-liquid chromatography of myo-inositol hexaacetate. The identity of myoinositol hexaacetate from bean samples was confirmed by mass spectrometry and chromatographic retention time. A standard curve prepared by plotting peak height vs. μg myoinositol hexaacetate was linear over the range studied, 0.2 to 0.6 μg. Peak heights were measurable in all samples, although inositol hexaacetate was not completely separated in California small white bean samples. An internal standard, perseitol, was used to correct for losses in the procedure. Hydrolysis of phytin was negligible during sample preparation or analysis. Recoveries of 12 to 40 μg inositol from 40 mg samples of California small white beans averaged 113%. These beans contained an average of 71 ppm inositol compared to 215 ppm inositol in similarly prepared pinto beans.
Colorimetric Determination of Phenylamide Pesticides in Natural Waters
Authors: El-Dib M A , Aly Osama A 
Published: February 2020

Abstract
Phenylamide pesticides include a great variety of compounds such as TV-phenylcarbamates, phenylureas, and anilides. A simple, rapid, and sensitive colorimetric method for their determination in natural waters has been proposed. Phenylamides are rapidly hydrolyzed in acid medium at elevated temperature (150–155°C), yielding the corresponding anilines. The latter compounds are diazotized and coupled with 1-naphthol to yield intensely colored azo dyes. Both phenylamides and aniline derivatives can be determinedined a sample in the presence of each other. The method is sensitive to 0.02 m g/L; coefficients of variation range between 6.0 and 0.2, according to the amount of phenylamide pesticide being measured.
The Determination of Hexachlorophene in Mammalian Tissues by Gas-Liquid Chromatography
Authors: Ulsamer A G 
Published: February 2020

Abstract
Hexachlorophene in mammalian tissues can be determined by extraction with ether-absolute ethanol (18 + 7), formation of the acetyl or methyl derivative, and gas chromatography with a column of 3% OV–101 on Gas-Chrom Q. Recoveries of hexachlorophene added to blood ranged from 86% at 0.005 μg/ml to 97% at 2.0 μg/ml, and for organs from 85 to 97%.
Spectroanalytical Parameters of Fungal Metabolites. III. Ochratoxin A1
Authors: Neely W C , West A D 
Published: February 2020

Abstract
Analytically useful spectroscopic data for k ochratoxin A, previously absent from the literature, are presented. The value of the extinction coefficient of the analytically preferable 333 nm absorption band in absolute ethanol was determined to be 4680±40 over the range , 1.9 × 10±6-4.8 × 10±4M. The possibility of ionization upon dilution is discussed. Ochratoxin A exhibits fluorescence and phosphorescence of approximately equal intensities. The lifetimes of these are 3.2 × 10±8 sec and 0.28 sec, respectively. Some photodecomposition occurred under prolonged light exposure.
Rapid Method for Analyzing Resmethrin Content in Formulations and Determining the cis-trans Ratios
Authors: Heath Robert R 
Published: February 2020

Abstract
Total resmethrin was determined in test formulations prepared in petroleum distillates and in micronized dust formulations by gasliquid chromatography. The ratio of the 2 geometrical isomers was obtained from the nuclear magnetic resonance spectrum of the parent acid after hydrolysis of resmethrin. This method of determining isomer ratios was faster and somewhat more accurate than the infrared method.
Gas Chromatographic Determination of Phosphamidon Insecticide in Formulations
Authors: Carlstrom A A 
Published: February 2020

Abstract
The GLC method described is specific for measuring 4 components of Phosphamidon Insecticide—deschlorophosphamidon, α-phosphamidon, β-phosphamidon, and γ-chlorophosphamidon. The sample is extracted with acetone, an internal standard (dicyclohexyl phthalate) is added, and the solution is diluted to volume and injected into a gas chromatograph equipped with a flame ionization detector. Although the GLC peak areas for phosphamidon are not linear over a wide range of concentration, good results are obtained when sample and standard concentrations are matched to within 10%. A 1.21% coefficient of variation was found for 19 repetitive injections.
Quantitative Determination and Confirmation of Low Levels of Diethylstilbestrol in Feeds
Authors: Jeffus Marshall T , Kenner Charles T 
Published: February 2020

Abstract
A method for the determination of diethylstibestrol in feeds, which is based on official first action method 38.048–38.051, is proposed. Interfering feed extractives are removed by using a tripotassium phosphate-Celite column prior to measurement at 415 nm before and after irradiation. Recoveries of equilibrated standards added to Soxhlet extracts of several samples averaged 94.3% compared to 86.3% by the official method. The background absorbance at 415 nm obtained by using the proposed method was approximately 6% of the background by the official method for solutions containing equivalent amounts of sample. A thin layer chromatographic method is also included for the confirmation and identification of the cis and trans isomers of the drug. The proposed method has been found satisfactory for the quantitative determination of 0.55–44 ppm diethylstilbestrol and the thin layer chromatographic procedure can detect as little as 0.07 ppm.
Analytical Profile of Scotch Whiskies
Authors: Schoeneman Robert L , Dyer Randolph H 
Published: February 2020

Abstract
In this study, 13 Scotch grain whiskies and 34 Scotch malt whiskies were characterized by both chemical and physical analyses. In addition, 34 blended Scotch whiskies secured in the United States were examined. Official AOAC methods were used to determine the components commonly used in characterizing distilled spirits. In addition, potassium, sodium, copper, zinc, iron, calcium, magnesium, and lead were determined by atomic absorption spectroscopy. Characteristics of the present samples are compared to American whiskies.
Ultraviolet Spectrophotometry of Phenothiazine Derivatives and Analogs
Authors: De Leenheer André 
Published: February 2020

Abstract
Ultraviolet spectral data have been tabulated for 41 phenothiazine derivatives and analogs. The general appearance of the spectra is caused by the structure of the tricyclic π-system, whereas spectral shift effects are produced by R2 substituents. Acceptable correlations were found between the location of absorption maxima and Hammett’s σm and σρ constants of R2 substituents for the phenothiazine derivatives examined.
Determination of Neostigmine Bromide by Ion-Pairing Column Chromatography
Authors: Kling Rita E 
Published: February 2020

Abstract
A rapid and sensitive method for the assay of neostigmine bromide (NBr) in tablets and ophthalmic solutions has been developed. NBr is isolated from its pharmaceutical excipients by the ion-pairing partition column chromatographic principles of Levine and Doyle followed by ultraviolet determination of its alkaline hydrolysis product. Standard recoveries of NBr from simulated tablet mixtures and ophthalmic solutions averaged 99.8%. The standard deviation of repeated analyses of commercial products was less than±1%. The results of the proposed method for commercial products are in good agreement with the USP XVIII procedure. The procedure is applicable to individual tablet assay.
Gas-Liquid Chromatographic Separation of N-Acetyl-n-butyl Esters of Amino Acids
Authors: Vincent Phillip G , Kirksey Jerry 
Published: February 2020

Abstract
Gas-liquid partition chromatography of a number of N-acetyl-n-butyl esters of amino acids has been investigated. Results obtained with a column packed with methyl silicone grease (DC-200, 12,500 est viscosity) were better than those reported for Carbowax 1540 or hydrogenated vegetable oil. Amino acid derivatives were distinctly resolved on methyl silicone grease columns. Preliminary determinations were obtained for synthetic mixtures of the acids. The method should prove a useful adjunct to current techniques for the separation and quantitative measurement of amino acids.
Fluorometric Determination of Oxytetracycline in Premixes
Authors: Katz Stanley E , Fassbender Carol A 
Published: February 2020

Abstract
A simple fluorometric procedure for Oxytetracycline, in which a highly sensitive fluorometer and ultrapure deionized water are used to eliminate background fluorescence, is presented. Recoveries from fortified extracts of commercial premixes ranged from 95.0 to 102.5%; the ratio of results of microbiological to fluorometric methods ranged from 0.97 to 1.05%.
Determination of Crystallinity of α-D-Lactose by Far Infrared Spectroscopy
Authors: Susi Heino , Ard Jesse S 
Published: February 2020

Abstract
The far infrared absorption procedure for the evaluation of crystallinity of α-D-lactose is based on the oil-mull technique and the use of barium carbonate as an internal standard. Fixed slits, ordinate scale expansion, and very slow scanning rates are employed for analysis, and absorbance values are measured by the baseline technique. The method is applicable to samples such as whey solids and other dehydrated dairy products; however, the samples must be uniformly ground before analysis. For 10 test samples, the mean square error is 1.51% and the maximum error is about 2%. The time required for a single analysis is about 1 hr.
Thin Layer Chromatographic-Volumetric Determination of O,O-Dimethyldithiophosphoric Acid and Its Alkaline Salts in Technical Preparations
Authors: Bazzi Brunetto , Fabbrini Riccardo , Radice Marco 
Published: February 2020

Abstract
O,O-Dimethyldithiophosphoric acid and its alkaline salts are separated from impurities in technical preparations by thin layer chromatography on silica gel H, using 2 solvent systems: n-hexane-acetone and isopropanol-ammonium hydroxide. The plate is sprayed with palladium chloride for detection of the compounds. The area is scraped off and the compounds contained in this area are bromometrically titrated for quantitative determination. Good recoveries were obtained for O,O-dimethyldithiophosphoric acid and its sodium and potassium salts in pure samples and technical preparations.
Gamma Spectroscopic Determination of Cesium-137 in Milk, Using Simultaneous Equations: Collaborative Study
Authors: Baratta Edmond J , Knowles F E 
Published: February 2020

Abstract
A gamma spectroscopic method, using a sodium iodide (thallium-activated) crystal, was evaluated by 25 collaborators for the determination of cesium-137 in milk. Overall average recoveries of 295±18.1 and 53±5.3 pCi/L were obtained for samples containing 305 and 52 pCi/L, respectively. These samples also contained iodine-131 and barium-140, which did not interfere with the analyses. The slight bias on the low side and the greater dispersion of results for the low level sample were not considered serious. The method has been adopted as official first action.
Determination of Strontium-90 in Water: Collaborative Study
Authors: Baratta Edmond J , Knowles F E 
Published: February 2020

Abstract
A procedure involving carbonate precipitation and purification with nitric acid was evaluated by 11 collaborators for the determination of strontium-90 in water. The ingrowth level of yttrium-90 is counted and this activity is used to calculate the strontium-90 activity present. The accuracy of the method ranged from 9 to 16% and within-laboratory precision ranged from 13 to 19% for strontium-90 levels of 28.2 to 99.6 pCi/L. A slight bias on the low side, caused by individual laboratory techniques, was not considered serious. The method has been adopted as official first action.
Ion Exchange Determination of Strontium-89 and Strontium-90 in Milk: Collaborative Study
Authors: Baratta Edmond J , Knowles F E 
Published: February 2020

Abstract
A method for the determination of strontium-89 and strontium-90 in milk, involving ion exchange and purification with nitric acid, was evaluated by 11 collaborators. The accuracy of the method for strontium-89 ranged from 2 to 56% and the within-laboratory precision ranged from 11 to 76% for a concentration range of 68–480 pCi/L; values for strontium-90 in a concentration range of 50.2–116.2 pCi/L were 6.4 to 10 and 4 to 11%, respectively. The slight bias on the high side for strontium-90 was not considered serious. The collaborators had difficulty with strontium-89 analyses, as shown by the high precision and accuracy estimation values.
Analysis of Aflatoxins in Sunflower Seeds and Sunflower Meal
Authors: Karmelic Julia , Israel Mery , Benado Sara , Leon Carmen 
Published: February 2020

Abstract
Aflatoxins are extracted from sunflower seeds and meal by chloroform, eluted from a silica gel column, and determined by thin layer chromatography (TLC), using chloroform-acetone-water-2-propanol as the developing solvent. In addition, the TLC step also removes interfering material from some sunflower varieties which is not removed by the cleanup column. Various silica gels were tested for cleanup efficiency. Recoveries of added B1, B2, G1, and G2 were satisfactory.
Thin Layer Chromatographic Detection of Thiabendazole and Benomyl in Fruits
Authors: Tjan Gwan H , Burgers L J 
Published: February 2020

Abstract
Thiabendazole and benomyl are extracted from fruit peels with ethyl acetate and the extracts are filtered. The filtrates are extracted with 0.1N HC1, adjusted to pH 6 with 0.1N NaOH, and re-extracted with ethyl acetate. The concentrated extracts are spotted on plates coated with silica gel GF-254. The fungicides are detected on the plates under shortwave ultraviolet light, after development with chloroform-acetone (8+2), as pink-blue spots on a light fluorescent background. The recovery of thiabendazole from fortified samples is satisfactory, but the recovery of benomyl is not quantitative. For greater specificity, an enzymatic inhibition technique is also described which may be used on the exposed silica gel GF-254 plate or on a silica gel G plate.
Collaborative Study of the Automated Determination of Nitrogen in Meat Products
Authors: Gantenbein Walter M 
Published: February 2020

Abstract
A modification of a previously reported method for nitrogen in meat products was subjected to collaborative study. Samples were dissolved in 1+1 sulfuric acid, cooled to room temperature, and presented to an Auto-Analyzer system. Digestion, dilution, and colorimetric measurement of nitrogen content were performed automatically. Seven collaborators participated in the study, analyzing 8 different samples in duplicate. Results of the study were satisfactory, with an average range of 0.95% protein, average standard deviation of ±0.39, and average coefficient of variation of 2.44%. The method has been found applicable to meat and meat products containing 0.8–4.0% nitrogen (5.0–25.0% protein).
Conditioning of Polyalkyl Glycol Liquid Phases for Flame Photometric Gas Chromatographic Analysis of Dursban and Its Oxygen Analog
Authors: Struble Dean L 
Published: February 2020

Abstract
Dursban and its oxygen analog were resolved by 3 liquid phases, Ucon 75-H-90,000 and Carbowaxes 20M and 20M TPA, on unsilanized, acid-washed Chromosorb W. The GLC responses and resolutions of the 2 compounds were dependent upon the conditioning of the packing before it was placed in the GLC columns. The most satisfactory results were obtained when the column packing was heated in the presence of atmospheric oxygen. The best liquid phase for the GLC analysis of Dursban and its oxygen analog was Ucon 75-H-90,000.
Gas-Liquid Chromatographic Method for the Analysis of Dichlozoline Residues in Grapes and Grape Products
Authors: Pack Donald E , Lee Hwalin , Bouco Léon , Sumida Seizo , Hisada Yoshio , Miyamoto Junshi 
Published: February 2020

Abstract
Dichlozoline residues are extracted from field-treated grapes and the must, juice, or wine derived from them with hexane and analyzed by gas-liquid chromatography, using electron capture detection. For residues below 0.5 ppm, a silica gel G column is used for clean-up. Recoveries of dichlozoline added to grapes at a level of 0.04 ppm and to must, wine, or juice at levels from 0.5 to 1 ppm were excellent. The limit of detection is 0.01 ppm.
Review of the Schoenemann Reaction in Analysis and Detection of Organophosphorus Compounds
Authors: Poziomek Edward J , Crabtree Eleanor V 
Published: February 2020

Abstract
This report reviews the chemistry of the Schoenemann reaction and describes the principles and applications in the detection of organophosphorus compounds. Emphasis is placed on the analysis of the very toxic compounds ethyl N,N,-dimethylphosphoramido cyanidate and isopropyl methylphosphonofluoridate. There are many literature publications and government reports which illustrate applicability of the Schoenemann reaction. Key literature references are mentioned throughout this report; also, there are many citations of unpublished data.
Fluorometric Determination of Decoquinate in Chicken Tissues
Authors: Stone Loyal R 
Published: February 2020

Abstract
Results are reported for a collaborative study of a fluorometric method for decoquinate in chicken tissues in the range 0 to 2.2 ppm. The drug is extracted from tissues by blending with methanol-chloroform. On addition of acid, decoquinate is separated in the chloroform phase and chromatographed on a Florisil column. It is eluted with 1% calcium chloride in methanol and determined by fluorescence measurement. The method has been adopted as official first action.