bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spectrophotometric Determination of BHA and BHT in Vegetable Oils
Authors: Johnson D P 
Published: February 2020

Abstract
Improved spectrophotometric methods have been developed for separate determinations of BHA and BHT in vegetable oils. The methods are applicable in the presence of other synthetic antioxidants and are adaptable to BHA and BHT concentrations ranging from 5 to 200 ppm. BHA is nitrosated directly in the oil and the nitroso product is isolated by a combination of solvent extraction and liquid chromatographic techniques. An alkaline solution of the product is measured spectrophotometrically at 480 mμ, and the absorbance is referred to a calibration curve to determine the BHA concentration. Both the 2- and 3-isomers yield approximately the same absorptivity, and Beer's Law is obeyed from 0 to 50 μg BHA/ml final solution. BHT is determined by its ultraviolet absorption at 283 mμ. The compound is separated from the oil by direct extraction into acetonitrile. BHT is isolated from BHA and other extraneous materials by chromatography on alumina
Determination of Nonfat Dry Milk in Meat Products with a Specific Enzymatic Assay
Authors: Hankin Lester 
Published: February 2020

Abstract
A method based on the specificity of the enzyme galactose oxidase for galactose is proposed for the determination of nonfat dry milk in meat products. This enzyme, coupled with peroxidase and a chromogen, o-tolidine, measures the amount of galactose liberated from the nonfat dry milk in the product by HC1 hydrolysis. A standard composed of nonfat dry milk is tested concurrently, thus providing a direct assay for this material. The proposed method is not influenced by carbohydrate-containing materials, other than nonfat dry milk, which may be present in the sample. Data are presented to show the validity of the method
Simple Method for Determination of Glycine and Niacin in Drug Mixtures
Authors: Egli Keith L , Romano Anthony 
Published: February 2020

Abstract
A method, based on the formol titration of glycine and the ultraviolet absorption of niacin, has been developed for the determination of these compounds in drug mixtures. Neither compound requires isolation for the determination. Glycine and niacin are identified by thin layer chromatography
Gas-Liquid Chromatographic Method for the Determination
of Fat-Soluble Vitamins. VI. Application to Pharmaceuticals
Containing Menadione
Authors: Hubbard W D , Sheppard A J 
Published: February 2020

Abstract
Gas-liquid chromatography has been used to quantitatively determine menadione (vitamin K3) in pharmaceuticals, using a 1% neopentyl glycol succinate column and a hydrogen flame detector. The gas chromatographic measurements compare favorably with results by the National Formulary methods on the same samples.
Determination of Saturated and Unsaturated Fatty Acids:
Comparison of Gas-Liquid Chromatographic, Thiocyanogen
Number, and Lead Salt-Ether Methods
Authors: Lacroix Denis E , Prosser A R , Sheppard A J 
Published: February 2020

Abstract
The weight per cent composition of the C16—Cis series of fatty acids in edible vegetable oils was determined by GLC, lead salt-ether, and thiocyanogen number methods. Total saturated and unsaturated fatty acid percentages obtained by GLC and the lead salt-ether methods were in poor agreement; the lead salt-ether unsaturated fatty acid percentages tended to be higher than the GLC values. The thiocyanogen number values for unsaturation were higher than GLC values lor every fat and oil analyzed except one. The polyunsaturated fatty acid percentages obtained by the thiocyanogen number method were not similar to the GLC values for about half of the fats and oils examined.
Interferences Encountered in Determining Potassium in
Fertilizers by Atomic Absorption Spectrophotometry
Authors: Hoover William L , Reagor John C 
Published: February 2020

Abstract
In the development of an atomic absorption method for the analysis of potassium, several interfering materials were found that influence the absorption of 7664.9A radiation by potassium. The same interfering materials had very little effect on absorption at 4044.1A. However, high phosphorus content caused varying amounts of interference at 4044.1A, depending on the presence of other ions. Various grades of fertilizer were analyzed by the proposed atomic absorption procedure at 4044.1A. Atomic absorption analyses, even though there was a low bias, compared favorably with analyses by STPB and other procedures used by commercial laboratories. The proposed atomic absorption method has merit because of its speed and simplicity
Comparison of the Automatic Dumas (Coleman Model 29A Nitrogen Analyzer II) and Kjeldahl Methods for the Determination of Total Nitrogen in Agricultural Materials
Authors: Morris G F , Carson R B , Shearer D A , Jopkiewicz W T 
Published: February 2020

Abstract
A wide variety of agricultural materials were analyzed for total nitrogen by the Kjeldahl and automatic Dumas methods. The recoveries of nitrogen compared favorably by both methods when a catalystassisted combustion technique was used in the automatic Dumas method. Statistical evaluation of the experimental data, as measured by standard deviation, showed that the Kjeldahl method was generally more precise than the automatic Dumas method
Studies of Losses of Pesticides During Sample Preparation
Authors: Chiba M , Morley H V 
Published: February 2020

Abstract
The loss of pesticide residues during sample preparation after extraction was studied. Filtration, partitioning and washing, concentration, and evaporation were examined separately, using 14C-labeled γ- BHC, p,p'-DDT, and dieldrin as representative insecticides. Washing-out of polar solvents was also investigated, using 14Clabeled methanol, acetone, and acetonitrile. Although losses of insecticide residues during filtration and partitioning and washing are relatively small, they are cumulative and cannot be neglected. Polar solvents are not completely removed by normal washing procedures. The possible significance of the presence of these trace amounts of polar solvents in column cleanup is discussed. Evaporation to dryness caused the most significant loss; it is not recommended even in the presence of soil co-extractives because they do not completely prohibit loss. A recommended standard procedure for soil extracts is given which yields quantitative recoveries of insecticides with five different solvent systems. The procedure should also serve as a guide for plant and animal extracts.
Staining Technique to Differentiate Insect Fragments, Bird Feathers, and Rodent Hairs from Plant Tissue
Authors: Stein Richard , Eisenberg William V , Brickey Paris M 
Published: February 2020

Abstract
A staining method is described in which plant material is differentially stained from insect fragments, rodent hairs, and bird feather barbules. Because the colors of the stained plant tissue contrast with that of the dyed extraneous material, counting of the contaminants becomes easier, rapid, and more accurate.
Collaborative Study of a Method for Sodium Lauryl Sulfate in Egg Whites
Authors: Wiskerchen John 
Published: February 2020

Abstract
A colorimetric method for the quantitative determination of sodium lauryl sulfate in liquid, frozen, and powdered egg white was studied by eight collaborators. Determinations were made on flake and powdered egg white at levels of 0.05, 0.1, and 0.2% (w/w) and on liquid egg white at levels of 0.006, 0.0125, and 0.0250% (w/w) sodium lauryl sulfate. The egg white is dissolved in water, and the protein is precipitated with ethanol and removed by filtration. An aliquot of the filtrate is evaporated to dryness, and the residue is dissolved in water and acidified with sulfuric acid. The sodium lauryl sulfate is complexed with Azure A, extracted into chloroform, and determined spectrophotometrically at 637 mμ. A blank determination is made on another aliquot of the filtrate by complexing the sodium lauryl sulfate with benzethonium chloride. This is a stable colorless complex. Average recoveries in the collaborative study were 98—102% with a mean deviation of 2.8—5.4%. It is recommended that the method be adopted as official, first action.
Collaborative Study of Microbiological Assay of Oxytetracycline in Feeds
Authors: Billman D C , Clark H 
Published: February 2020

Abstract
A collaborative study was made of a modification of the official AOAC method for the determination of oxytetracycline in feeds. This cylinder plate method uses Bacillus cereus var. mycoides, ATCC No. 11778, as the test organism. The modification consists of using a 20 g instead of a 10 g sample, of using an extraction flask instead of a mortar and pestle or a blender, and of filtering the assay solution. The average recovery of oxytetracycline by 12 collaborators was 92.4% with an average coefficient of variation of 13.5%. Assay precision, determined by computing standard deviations on the differences between pairs of similar materials, was estimated to be 7.4% at 10 g/ton and 5.9% at 25 g/ton. The method is recommended for adoption as official, first action.
Determination of Loss on Drying in Roasted Ground Coffee
Authors: McCarron Eleanor A 
Published: February 2020

Abstract
Moisture loss on drying was determined on five "regular grind" coffees by the air oven method at 105°C and vacuum oven method at 98—100° C before and after grinding. Results for unground and ground samples by the vacuum oven method were in good agreement; results between the two oven methods for unground or ground samples were generally less satisfactory. Collaborative study was conducted by the vacuum oven method only on four unground (as is) samples. Results were in reasonable agreement, and the method is recommended for adoption as official, first action.
Investigation of the Determination of Volatile Isothiocyanates in Mustard Seed and Flour
Authors: Rosebrook D D , Barney J E 
Published: February 2020

Abstract
A study of the variables in the AOAC and ASTA methods for determining volatile isothiocyanates in mustard flour and seed has led to development of a new method that is useful for both mustard flour and seed. The proposed method dispenses with the long reaction times and the digestion of the silver sulfide precipitate now required by the AOAC method. When mustard seed is analyzed, the ground seed is boiled in water for 3 min to solubilize the sinigrin, and yellow mustard flour is added as a source of enzyme. When mustard flour is analyzed, the boiling procedure is omitted Results are more reliable by the proposed method than by the AOAC or ASTA method and analysis can be completed in a single day.
An Improved Method for Determining Steam-Volatile Oil in Cassia
Authors: Rosebrook D D , Bolze C C , Barney J E 
Published: February 2020

Abstract
The variables that affect the determination of steam-volatile oil in cassia by the official ASTA method were examined in a preliminary study. On the basis of the results of this study an improved method was devised and was tested in a statistical program involving four types of cassias, two types of traps, two distillation rates, two sample weights, and two distillation times. Improvements in the method allow complete analysis in 3 to 5 hours, with an increase in the yield of steam-volatile oil and improved reliability.
Comparison of Flame and Burner Combinations in Atomic Absorption Spectroscopy
Authors: Perrin C H , Ferguson P A 
Published: February 2020

Abstract
Atomic absorption analyses of calcium, copper, iron, magnesium, manganese, and zinc on eight animal feed samples were conducted in which three different burners and six gas combinations were used under a variety of conditions. The statistical analysis demonstrated in most cases the superior accuracy of an oxygen-acetylene flame in a total consumption burner on solutions prepared by dry-ashing the samples.
Collaborative Study of Three Gas Chromatographic Dual Detection Systems for Analysis of Multiple Chlorinated and Organophosphorus Pesticides
Authors: Wessel John R 
Published: February 2020

Abstract
Six laboratories collaboratively studied three different gas chromatographic dual detection systems. The potassium chloride thermionic and electron capture detectors were arranged: (1) in parallel; (2) in series with a stream splitter between the detectors; and (3) in series. Systems 1 and 2 use the same type of thermionic detector, whereas a modification of this detector is used for System 3. Collaborative results show these systems to be equivalent for the quantitative measurement of multiple organophosphorus pesticides at 0.5 and 2.0 ppm. The pesticides studied were ronnel, ethion, Diazinon, malathion, methyl parathion, parathion, and carbophenothion. Operational and performance characteristics of dual detection and of thermionic gas chromatography are also discussed. It is recommended that all three systems studied be listed as official, first action for analysis of multiple pesticide residues
Improved GLC Method for s-Triazine Residue Determination
Authors: Tindle R C , Gehrke C W , Aue W A 
Published: February 2020

Abstract
An improved version of the alkali-flame detector with a movable electrode and rubidium sulfate as the coating material has been used for the analysis of atrazine, simazine, propazine, and prometryne. GLC conditions selected for optimum operation were as follows: column: 1.9 m X 3 mm i.d. Pyrex, packed with 10% w/w Reoplex 400 on 80—100 mesh Gas Chrom Z and operated at 200°C; flow rates: nitrogen 55 ml/min, hydrogen 30 ml/min, air 170 ml/min. When this technique was applied to the analysis of atrazine and simazine in corn, soil, and water samples, no purification of sample extracts was needed and recovery was quantitative. Minimum detectable limits were better than 0.5 ng triazine.
Collaborative Study of the Dye Binding Method Applied to Chocolate Milk Drinks, Cultured Buttermilk, and Half-and-Half
Authors: Sherbon J W 
Published: February 2020

Abstract
Collaborative studies of the dye binding method for chocolate-flavored milk drinks, cultured buttermilk, and half-and-half were conducted this year; ten samples of each product were tested in quadruplicate in seven laboratories. The precision of the method with these products was essentially the same as that for fluid milk. The withinlaboratory variations were very small and resulted in statistically significant interlaboratory variations; the actual differences were not of practical significance. It is recommended that these three products be accepted for testing for protein content by the dye binding method. Preliminary results on use of the dye binding method for analyzing nonfat dry milk show good precision; however, proper sampling and duplication procedures need to be established, and studies will continue. Studies will also continue on the required accuracies of reagent preparation, pH of buffer, and sample weighings to establish suitable tolerances.
Chemical Determination of Niacinamide in Multivitamin Preparations
Authors: Pelletier Omer 
Published: February 2020

Abstract
The AOAC method and the Pelletier and Campbell method for the assay of niacinamide in multivitamin preparations were compared in two collaborative studies. In the first study, three multivitamin sirup preparations were analyzed by six laboratories; the proposed method gave higher results for two preparations but lower results for the third. In the second study, four types of multivitamin preparations were analyzed; twelve laboratories reported on the chemical methods and three laboratories on the microbiological method. There was no difference in the mean values for two types of samples, but one sample of multivitamin tablets yielded mean values about 5% lower by the proposed method, suggesting the presence of a trace of niacin; with a multivitamin and mineral sirup the proposed method gave values about 6% higher than the AOAC method and 3% lower than the microbiological assay. The coefficient of variation for any sample in any laboratory by the AOAC method was about 14% in the first study and 1 1% in the second study; by the proposed method it was 4 and 9% in the same respective studies. It is recommended that the present AOAC method be modified by adjusting the pH of sample hydrolysates in the range of 2.5—4.5 instead of 7—9 to reduce the absorhance of the blanks, and that the method of Pelletier and Campbell be adopted as official, first action.
Determination of Sugars in Distilled Spirits by GLC
Authors: Martin Glenn E , Eib Nicholas K 
Published: February 2020

Abstract
The anomeric forms of glucose (α and β) and fructose were determined by GLC in both standard solutions and in distilled spirits, using sorbitol as an internal standard. The GLC method for fructose and α and β-glucose compares favorably with the AOAC method for concentrations from about 150 to 225 mg/100 ml. However, at concentrations below 100 mg/100 ml, the GLC method gives generally lower values, probably because the AOAC method measures the amount of reducing sugars and the GLC method measures only α and β-D-glucose and D-fructose
Collaborative Study of the Identification of Grape Varieties
Authors: Rice A C 
Published: February 2020

Abstract
Collaborative studies were conducted on the paper chromatographic method for anthocyanin pigments in Concord grape juice. Six unknowns plus a pure Concord reference sample were submitted to four collaborators with instructions to identify the unknowns as pure or adulterated. All samples were correctly identified by the collaborators. The limit of detection is about 1% (v/v) for California grape concentrates in Concord (or about 5% of the total grape solids present, assuming 68° Brix concentrate and 16° Brix Concord juice). For a color extractive, e.g., Italian grape color (Enocianina), the detection limit is about 1/2% (v/v). The method is recommended for adoption as official, first action.
Collaborative Study of a Polarimetric Method for l-Malic Acid
Authors: Fernandez-Flores Enrique , Johnson Arthur R , Blomquist Victor H 
Published: February 2020

Abstract
A method, utilizing the absorbance of lmalic acid, uranyl acetate complex, modifications of techniques developed by Hartmann for polybasic acids, and changes published by Vandercook, has been developed and collaboratively studied. This newly developed procedure will quantitatively determine l-malic acid in fruit juices, fruit drinks, jellies, and preserves. It is recommended that this method be adopted as official, first action and that application of the method to grape products be studied further.
Determination of Maltol and Ethyl Maltol in Apple Juice by Gas-Liquid Chromatography
Authors: Gunner S W , Hand B , Sahasrabudhe M 
Published: February 2020

Abstract
The qualitative and quantitative analysis of maltol and ethyl maltol in apple juice is described. The compounds were extracted with ethyl acetate and, after the addition of 2,6-dimethoxyphenol as internal standard, they were analyzed by gas-liquid chromatography as such or as their trimethylsilyl derivatives. Recovery of maltol and ethyl maltol was dependent on the method of isolation and ranged from 92 to 97.5% in the method of choice
Oxalate Determination: Analytical Problems Encountered with Certain Plant Species
Authors: Abaza R H , Blake J T , Fisher E J 
Published: February 2020

Abstract
Accurate quantitative determination of oxalate in chemical analyses of edible plants is important because oxalate is a poisonous compound. The traditional KMn04-oxalate reduction-oxidation (Dye) method of analyzing for plant oxalate content presents two problems: (a) Plant pectins are not entirely separated in the determination of watersoluble oxalate and interfere in the oxidation of oxalate; and (b) a brownish-black precipitate containing ferrous iron is precipitated at the same pH as calcium oxalate and the precipitate interferes in determination of both water- and acid-soluble oxalate. Our modification of the Dye method consists of (a) using double-distilled water as the diluting medium, (6) increasing the acidity of the water-soluble oxalate medium after plant digestion to obtain complete removal of pectins, and (c) eliminating the ferrous iron-containing precipitate by filtration. Oxalate in the ferrous iron-containing precipitate is determined as calcium and magnesium salts by atomic absorption spectrophotometry; the value thus obtained is added to the oxalate value from the oxidation- reduction method. An indirect analytic method for oxalate, in which all of the oxalate was precipitated as the calcium salt and then measured by atomic absorption spectrophotometry, proved to be inaccurate
An Evaluation of the Method for the Determination of Added Phosphate in Ham
Authors: Kamm L , Coffin E 
Published: February 2020

Abstract
Different areas along the length of individual fresh pork legs were shown to vary in P factor (phosphorus: protein ratio). This variation, the effect of curing gains, and the fatness of the leg are significant in the determination of added phosphate in cured hams. As a result, it is proposed that added phosphate in ham should be expressed on a fat-free green weight basis
Analytical Profile of Cistern Room Whiskies
Authors: Schoeneman Robert L , Dyer Randolph H 
Published: February 2020

Abstract
In this study, 85 bourbon mash, 10 rye mash, and 17 corn mash cistern room whiskies from 42 different distilleries were characterized by both chemical and physical analyses. Determinations, using official AOAC methods, were made on the volatile components commonly used in characterizing distilled spirits. In addition, gas-liquid chromatography was used to quantitatively determine ethyl acetate, n-propyl, isobutyl and isoamyl alcohols, and a colorimetric procedure was used to determine esters. Characteristics of the present samples are compared to those reported in studies made as early as 1898. Also, a tabulation of the pertinent data on mashing, fermentation, and distillation techniques for each sample is included
Rapid Confirmatory Test for Aflatoxin B1, Using Bacillus megaterium
Authors: Clements Nancy Lowe 
Published: February 2020

Abstract
Growth inhibition of Bacillus megaterium NRRL B-1368. in response to anatoxin B1 provides a simple and rapid technique to supplement thin layer chromatographic identification of aflatoxins. Less than an hour is required to set up the test, and results are obtained after overnight incubation (15—18 hr). The test is sensitive to as little as 1 µg aflatoxin B1.
Collaborative Study of Molecular Weight Determination Applicable to Samples with Molecular Weights Less Than 500
Authors: Ogg C L , Scroggins L H 
Published: February 2020

Abstract
A method for determining molecular weights employing the thermoelectricvapor pressure technique was tested by 13 collaborators. The samples used in the study were benzoic and nicotinic acids, n-hexadecylamine, methylpentadecyl ketone, benzylisothiourea hydrochloride, and sulfanilamide. Data from the six samples were analyzed statistically by Youden's technique for collaborative tests. Most deviation between laboratories was due to random errors; systematic errors were low. Choice of solvent and standard were critical. Methanol was shown to be unsatisfactory as a solvent. It is recommended that the method be adopted as official, first action.
TLC-PJnzyme Inhibition Procedure to Detect Some Carbamate Standards and Carbaryl in Food Extracts
Authors: Wales Patricia J , McLeod H A , McKinley W P 
Published: February 2020

Abstract
The TLC-enzyme inhibition method of Mendoza et al. for organophosphorus pesticides was extended to some carbamates. At the optimum pH (8.32), the minimum quantities detected were: 5 ng carbaryl; 10 ng Banol®; 50 ng Mesurol® and Zectran®; 500 ng Matacil®; and 1 µg Baygon®. Bromine treatment converted the carbamates to compounds with different sensitivities and, sometimes, different migration rates. Carbaryl added to apples, beets, cabbage, carrots, lettuce, raspberries, and poultry meat was extracted and detected by the TLC screening procedure. Spots produced by extracted carbaryl were comparable to those of standards, indicating quantitative recoveries.