bluuebunny/crossref_metadata_2025_split huggingface dataset:
Colorimetric Determination of Bismuth in Bismuth Subsalicylate Oil Suspension
Authors: Pinella Salvatore J 
Published: February 2020

Abstract
A study was made of a colorimetric determination of bismuth in bismuth subsalicylate oil suspension, similar to that of Official Methods of Analysis. The method depends upon the formation of a yellow bismuth-thiourea complex which exhibits maximum absorption at 465 mμ. Sesame oil is removed by ether extraction after HNO3 hydrolysis and the bismuth nitrate formed is converted to bismuth-thiourea complex with 2.5% thiourea solution in HNO3 (1 + 9). The color complex is stable and follows Beer’s law. The method is comparatively specific for bismuth, since only vanadium and antimony give similar color. It is satisfactory at concentrations as low as 50 μg of bismuth in the final solution. Nine collaborators reported favorable results; it is recommended that the method be adopted as official, first action.
Simultaneous Determination of Esters of 2,4-D and 2,4,5-T in Pesticide Formulations
Authors: Milner M P , Holzer F J , Leary J B 
Published: February 2020

Abstract
A simple and reliable method is described for simultaneously determining esters of 2,4-D and 2,4,5-T. After extraction of the sample with chloroform, the chloroform is evaporated and a hexane solution of the residue is passed over a Florisil column to remove interferences. The esters are then eluted from the column with chloroform and measured spectrophotometrically by using that part of the ultraviolet spectrum where difference between 2,4-D and 2,4,5-T makes possible the measurement of both in the presence of each other.
Infrared and Ultraviolet Spectrophotometric Methods for Rotenone
Authors: Rund Robert C 
Published: February 2020

Abstract
Nine collaborators participated in this year’s study, and their results on the official method vs. ultraviolet vs. infrared are presented and interpreted. The unique part of this program was the testing of these methods on resins, circumventing variations introduced by extraction. The spectrophotometric procedures were shown to be suitable for official, first action adoption and were so recommended.
Determination of Arsenic in Pesticide Formulations
Authors: Carey William F 
Published: February 2020

Abstract
An ion exchange method for the determination of arsenic in pesticide formulations was compared with the official distillation method. Data submitted by 16 collaborators showed that the ion exchange method was superior in accuracy and precision to the distillation methods. The ion exchange method for determining arsenic in pesticide formulations is recommended as official, first action.
Ion Exchange Resin Separation of Calcium and Strontium
Authors: Breault Eugene A 
Published: February 2020

Abstract
Calcium and strontium were separated on an Amberlite IR-120 resin column with ethylenediaminetetraacetic acid, and calcium was determined spectrophotometrically in the presence of ethylenediaminetetraacetic acid. Calcium recovery from the CaEDTA complex was 85% at 100 μg level. Recoveries of calcium from the CaEDTA complex in the presence of large quantities of EDTA were improved with the addition of copper chloride. Calcium and strontium were separated on the Amberlite IR-120 column; ammonium EDTA was used to elute the calcium. Recovery of calcium contaminated with 40% strontium was 100%. The remainder of the strontium, approximately 47%, was recovered free of calcium. A total of 86% of the strontium added was found.
Extraneous Material in Egg Products
Authors: Thrasher Joel J 
Published: February 2020

Abstract
Methods 36.039 (a)-36.039 (d) have been combined and condensed. Changes include a pancreatin digestion of dried egg whites rather than the current Protease F® method. A collaboratively tested method for the chemical identification of avian excrement is being proposed to replace method 36.041, which lacks the desired specificity.
Urine in Grain
Authors: Keppel George E 
Published: February 2020

Abstract
The method for urine in grain was studied collaboratively. In this method the grain is sprayed with a magnesium uranyl acetate reagent and examined under a short-wave ultraviolet lamp. If a grain kernel has come in contact with anything containing a sodium compound, such as rodent urine, a greenish fluorescence is visible on the kernel. These suspect kernels are tested for urea by both the ureasebromthymol blue paper test, and the xanthydrol test. Results from the eight collaborators were considered satisfactory. Recoveries varied from 67 to 100% for wheat, 0 to 100% for field corn, 60 to 100% for popcorn, and 33 to 100% for oats. It was recommended that the method be adopted as official, first action and that studies be continued.
Filth in Fruit Paste
Authors: Wheeler Helen H 
Published: February 2020

Abstract
Development of a method for recovering all types of filth encountered in fruit paste has been initiated. A number of people were consulted about their experiences in examinations of fig paste by method 36.053 and their efforts to improve recovery of rodent hairs, fly eggs, and maggots by supplementary or substitute procedures. Their answers indicate that a method incorporating extensive digestion of the fruit tissue to liberate filth elements, followed by sieving on a No. 140 screen and washing forcibly with a spray of water to reduce the amount of fruit tissue, then examining the sieve residue microscopically for insects and hairs, appears feasible. Application of this procedure to a commercial straight Calimyrna fig paste resulted in improved filth recovery compared to the AOAC method but proved time-consuming due to the amount of residual fig tissue on the sieve. Kerosene-water flotation treatment of the washed residue on the screen expedited the counting of filth elements, giving recoveries intermediate to those obtained by the AOAC method and direct microscopic examination of digested and sieved residues. It is recommended that the study be continued.
Peroxidase in Frozen Vegetables
Authors: Joslyn M A , Neumann H J 
Published: February 2020

Abstract
A collaborative study was made of ascorbic acid oxidation assay and the Morris test paper procedure for determining the amount of peroxidase in frozen vegetables. Uniform samples of ground, frozen peas and spinach were each blanched to 2 levels of activity. The ascorbic acid oxidation values were computed; 3 of 6 collaborators on the ascorbic acid oxidation test agreed fairly closely. The ascorbic acid oxidation procedure is recommended as first action. Results with the Morris test paper, reported by 8 collaborators, revealed considerable range in color reaction time in repeated observations by individual collaborators and between collaborators. Variations in test papers and in subjective judgment of individuals using these test papers indicate that each batch of papers prepared should be tested against standardized samples or against a standard peroxidase test. The test paper is useful for rapid but only semi-quantitative assay.
Fatty Acid Composition of Oil from Roasted and Unroasted Peanuts by Gas-Liquid Chromatography
Authors: Iverson John L , Firestone David , Horwitz William 
Published: February 2020

Abstract
The fatty acid composition of oil extracted from 22 samples of roasted peanuts was examined by gas chromatography. The major components (&gt; 1%) were palmitic, stearic, oleic, linoleic, arachidic, cis-11-eicosenoic (20:1), behenic (22:0), and lignoceric acids (24:0) . The identity of cis-11-eicosenoic acid was established by gas chromatography of its reduction products after ozonolysis of a sample collected from the gas chromatograph. Approximately 0.4% hexacosanoic (26:0) was present in the oils as well as trace amounts of odd chain-length saturated fatty acids (13—27 carbon atoms). Roasting the peanuts did not change the fatty acid composition of the extracted oil. The fatty acid composition of commercial peanut oils is similar to the composition of oils from roasted peanuts.
A Short Method of Testing Petroleum Waxes for the Presence of Polycyclic Aromatic Hydrocarbons
Authors: Lijinsky William , Domsky Irving , Raha Chitta R 
Published: February 2020

Abstract
A method for determining the possible presence of carcinogenic polycyclic aromatic hydrocarbons in petroleum waxes is based o n the maximum absorbance within four wavelength ranges of an extract prepared by chromatography. The procedure involves chromatography on silica gel and partition of the adsorbate between cyclohexane and nitromethane, followed, if necessary, by a second chromatography on silica gel impregnated with nitromethane.
Total Solids in Oysters
Authors: Durrant Norman W 
Published: February 2020

Abstract
Preliminary work is underway on studies of two methods for determining total solids in oysters: (a) the Radarange in conjunction with the forced draft oven, and (b) the Ohaus moisture determination balance. The results obtained by each method are compared directly with the official AOAC procedure. A 10 g sample is weighed into a Pyrex petri dish, exposed in the Radarange 4 minutes, and then placed in a forced draft oven set at 100°C for 20 minutes at full draft. The Ohaus moisture determination balance was calibrated to utilize a 9 cm diameter aluminum dish. The sample is weighed directly on the balance, and the heater is lowered over the sample long enough to dry the sample. This method is rapid (approximately 10 minutes), but only one sample may be determined at one time. Studies will be continued.
Total Solids and Ether Extract in Fish and Other Marine Products
Authors: Risley H M 
Published: February 2020

Abstract
The first action modified Babcock method for crude fat in canned fish, 18.013, was studied collaboratively on 2 samples of canned fish and 2 samples of frozen fish. The results were compared with those by the official acid hydrolysis method, 18.012. Nine analysts, representing 5 different laboratories, cooperated in the study. The results show that the modified Babcock method has about the same degree of reliability as the acid hydrolysis method. It was recommended that the method be made official, after some slight changes in the wording.
Rapid Spectrophotometric Method for Determination of Chlorogenic Acid in Leaf Tobacco
Authors: Oakley Elizabeth T , Millham John O 
Published: February 2020

Abstract
A simple, rapid, quantitative procedure has been devised to measure chlorogenic acid in a 75% aqueous ethanolic extract of ground tobacco. The absorbance of the extract at 330 mμ is directly proportional to the concentration of chlorogenic acid, provided a suitable background line is drawn to correct for interfering nonpolyphenolic substances. Analysis of a series of eight bright tobacco samples has shown large variations among leaves from different stalk positions, with a very definite trend toward higher chlorogenic acid content nearer the top of the stalk. The chlorogenic acid content of burley tobaccos appears to be extremely low. The precision of replicate analyses has been found to be ± 3%, relative, for virtually all samples analyzed. Many vary less than 1% between duplicate determinations.
Comparison of Methods for Recovery of Insect Fragments From Date and Fig Paste
Authors: Faen G 
Published: February 2020

Abstract
Comparison of two flotation methods for the recovery of insect heads and other insect fragments from both date and fig paste indicated no significant differences between the two methods, although the gasoline flotation method was found preferable. There was also no significant difference between the participating analysts or laboratories. Three trappings were found necessary for complete recovery, irrespective of the method. The use of insect heads was found to be a sufficiently reliable criterion of the number of whole insects.
Solid Sampling Device for Direct Gas Chromatographic Analysis of Spices
Authors: Stahl W H , Sullivan J H , Voelker W A 
Published: February 2020

Abstract
In developing gas chromatographic methods for spice analysis, a solid sampling device was used to eliminate the tedious and time-consuming preparation of samples by steam distillation. The device can be used only with the ionization detector. Analyses compare favorably with those on steam-distilled samples.
Use of Detergents in the Analysis of Fibrous Feeds. II. A Rapid Method for the Determination of Fiber and Lignin
Authors: Soest P J Vax 
Published: February 2020

Abstract
The capacity of cetyl trimethylammonium bromide to dissolve proteins in acid solution has been utilized in development of a method, called acid-detergent fiber method (ADF), which is not only a fiber determination in itself but also the major preparatory step in the determination of lignin. The entire procedure for determining fiber and lignin is considerably more rapid than presently published methods. Compositional studies show ADF to consist chiefly of lignin and polysaccharides. Correlations with the new fiber method and digestibility of 18 forages (r = —0.79) showed it to be somewhat superior to crude fiber (r = —0.73) in estimating nutritive value. The correlation of the new lignin method and digestibility was -0.90 when grass and legume species were separated.
Evaluation of the Molybdovanadate Photometric Determination of Phosphorus in Mixed Feeds and Mineral Supplements
Authors: Parks Paul F , Dunn Dorothy E 
Published: February 2020

Abstract
The molybdovanadate method was compared to AOAC method 22.061 and a molybdenum blue method for analysis of phosphorus in mixed feeds and mineral supplements. Six mixed feeds and four mineral supplements ranging from 0.7 to 12.5% P were each analyzed 6-9 times by each of the methods. Average coefficients of variation for the three methods over the phosphorus range studied were: AOAC, 2.74%; molybdovanadate, 3.07%; molybdenum blue, 6.93%. The molybdovanadate method was superior to the molybdenum blue method for samples containing more than 2.5% P and the reagents used in the former method were more stable. The molybdovanadate method was found to be as accurate as the AOAC method and requires less time for analysis.
A Comparison of the Relative Amounts of Tissue Esterases in Liver and Kidney Homogenates
Authors: Read Sheila I , Mckinley W P 
Published: February 2020

Abstract
The relative amounts of the ali-esterases in beef and rabbit kidney and liver homogenates have been evaluated quantitatively, after resolution of the esterases by starch-gel electrophoresis. The relative amounts of total ali-esterases in livers and kidneys of a number of animals and fowl have been determined. The data presented and other unpublished data show that the ali-esterase content of tissues increases with age and that there is a sex difference.
A Method for the Analysis of Chlorinated Benzenes in Clams (Mercenaria mercenaria) and Oysters (Crassostrea virginica)
Authors: Schwartz N , Gaffney H E , Schmutzer M S , Stefano F D 
Published: February 2020

Abstract
A method of analysis for mixtures of chlorinated benzenes in clam (Mercenaria mercenaria) and oyster (Crassostrea virginica) samples is reported. The method involves Soxhlet extraction with n-hexane-isopropanol (1:1) for 6 hours followed by gas chromatographic separation on a Silicone gum column with an electron affinity detector. Quantities as small as 10-10 g are detectable. Average recovery of added Polystream (a mixture of chlorinated benzenes) was 99% for clam samples and 104% for oyster samples. Recoveries were based on reading the 1,2,3,4-tetrachlorobenzene peak. The relative precision for triplicate chromatograms, averaged over all levels, was ± 5%.
The Quantitative Determination of Mixed Sulfonamides by Paper Chromatography
Authors: Kunze Frieda M , Espinoza B Luis 
Published: February 2020

Abstract
A simplified quantitative procedure for the determination of mixed sulfonamides in pharmaceuticals is presented. The components are resolved by paper chromatography and located by their fluorescence under short wavelength ultraviolet light. They are then eluted and determined colorimetrically by a revised Bratton-Marshall technique. Total time of analysis is less than 4 hours. Recoveries averaged 98.8% with a range of 95.7 to 103.4%. Mean deviation from the average was 1.4%.
Determination of Ergotamine Tartrate in Tablets Containing Cyclizine Hydrochloride
Authors: Alexander Thomas G 
Published: February 2020

Abstract
The official AOAC methods for the analysis of ergotamine tartrate tablets have been modified to permit analysis of samples containing cyclizine. The effect on the assay color reaction of benzhydrol, a breakdown product of cyclizine, was studied. The identity and purity tests have been modified to remove interferences due to cyclizine.
Rapid Field Method for Determination of Fluoride in Plants
Authors: Ross James M , Wade Robert H , Benedict Harris M 
Published: February 2020

Abstract
A colorimetric reaction, involving the cerium III-alizarin complexan reagent, is described for the simple, semiquantitative determination of excess amounts of fluoride. A method is outlined that may be used in the field for the determination of fluoride in plants in excess of 40 ppm.
Evaluation of Protein in Foods. X. Effects of Source and Concentration of Dietary Fat on Protein Efficiency Ratio (PER) Values
Authors: Morrison A B 
Published: February 2020

Abstract
Studies were conducted on the effects of the concentration and source of dietary fat on PER values. At the 20% level, degummed rapeseed oil depressed PER of isolated soybean protein or casein, whereas corn oil, lard, or margarine had no effect. In contrast to results with these proteins, 20% rapeseed oil had no effect on PER of fish flour. Covariance analysis and paired feeding studies showed that the effects of rapeseed oil on PER could be explained by its influence in reducing food consumption. The high level of rapeseed oil had no effect on efficiency of nitrogen retention, as measured by net protein utilization.
Substitution of 10% rapeseed oil for 10% corn oil in standardized PER assays had no significant effect on PER values of peas, casein, or whole wheat flour. This finding provides assurance that in standardized assays, in which the level of dietary fat is set at 10%, PER values are not influenced by the composition of the dietary fat.
Yeast Resynthesis of Thiamine: A Modified Procedure Utilizing Ultrasonic-Treated Yeast
Authors: Weeks Cora E , Deutsch Mike J 
Published: February 2020

Abstract
A modified procedure for the yeast resynthesis of thiamine from its thiazole and pyrimidine moieties has been developed. The method utilizes ultrasonic exposure of the yeast prior to a twohour incubation period. Samples were sub-potent when received in the laboratory or were subjected to conditions which induced degradation of the vitamin. Following incubation, the vitamin was recoverable to varying degrees depending on the nature of the degradation treatment, the amount of decomposition, and sample characteristics.
Variables Affecting the Determination of Crude Fiber
Authors: Hallab Abdul H , Epps Ernest A 
Published: February 2020

Abstract
The effects of time, concentration, and volume on determination of crude fiber have been studied on 12 materials. Results for crude protein and lignin content of crude fiber residues, determined by use of an acid detergent solution, hexadecyltrimethylammonium bromide, were compared with the AOAC crude fiber method. Variation in volume does not affect crude fiber. Most of the acid and soda digestion occurs in the first 15 minutes; thereafter solubilization is slow. Small variations in concentration have little effect on the results obtained. Precision in crude fiber determination demands rigid adherence to procedural details. Crude fiber contains some residual crude proteins and approximately onehalf of the original lignins. Crude fiber should be replaced by a more nutritionally significant determination.
Column Chromatographic Determination of Certifiable Colors in Lipsticks
Authors: Silk Rachel Sclar 
Published: February 2020

Abstract
Column partition chromatography on Celite is used to separate the colors present in lipsticks. In the proposed procedure the immobile phase is aqueous alcohol plus ammonium hydroxide. A small portion of lipstick is ground with a portion of Celite containing the aqueous immobile phase and packed on top of a prepared colrate umn. Solvents of increasing polarity are used to elute individual colors except for one binary mixture. D&C Red No. 19 and D&C Red No. 36 and/or D&C Orange No. 17 elute together.
Determination of Submicrogram Amounts of Mercury in Inorganic Pigments by the Photometric Mercury Vapor Procedure
Authors: Wenninger John A , Jones John H 
Published: February 2020

Abstract
A rapid method has been developed for the determination of submicrogram quantities of mercury in inorganic pigments. The method is based on the ultraviolet photometric mercury vapor procedure and utilizes a commercially available instrument designed for the detection of mercury vapor in the atmosphere. The method requires no pretreatment of the sample such as digestion and isolation of the mercury. Samples are heated directly and the amount of mercury liberated is estimated from the response of the mercury vapor meter. The method will detect 0.01 μg of mercury. A precision of ± 0.005 μg of mercury is attained at the level of 0.03 μg.
The Effect of Handling and Processing on the Freezing Point of Milk
Authors: Henderson J Lloyd 
Published: February 2020

Abstract
certain amount of dilution of milk with water is difficult to prevent because of current handling and processing techniques. Some of the factors that may cause changes in freezing point are vacuum pasteurization, operation of vacuum pasteurizers so that the temperature does not drop more than 20°F, variations in sterilization, and holding milk frozen. High-temperature short-time pasteurization does not change the freezing point materially if proper sampling procedures are used; the same applies to homogenization. The effect of handling and processing is due largely to carbon dioxide removal or changes in the solubility of solutes.
The Variability of the Freezing Point of Fresh Raw Milk
Authors: Henningson R W 
Published: February 2020

Abstract
The freezing point value is generally recognized as the least variable property of milk and the best single index of "added water." The lactose and chloride concentration of milk account for about 75% of the freezing point depression, and one tends to compensate for the changes in concentration of the other. Most of the variability in the freezing point value has been attributed to changes in the concentration of the non-chloride ash fraction of milk. The official upper limit in the United States is —0.530°C. Evidence exists that the freezing point value of milk varies with season, feed, ambient temperature, grazing, carbohydrate content of the ration, breed, time of milking, access to water, weather, morning or evening milking, and the time interval between feeding and milking. Many of these factors are interrelated. Until recently all published values for United States herd milk samples ranged from —0.510 to —0.585°C, and for individual cows from —0.513 to —0.583°C. The greatest difference reported in the United States between morning and evening milk samples is —0.013°C. The reported range for United States authentic samples is -0.532 to -0.578°C.
Naturally Occurring Bromides in Nonfat Dry Milk: Determination and Levels
Authors: Pedraja Rafael 
Published: February 2020

Abstract
A modified method has been developed for the determination of inorganic bromide in nonfat dry milk. It is based on the method of Shrader, et al. (treatment of the sample with alcoholic KOH and ashing in the presence of NaOH and sodium peroxide) but uses a larger amount of NaOH to produce a semifusion state under ashing. Data indicate substantial recovery of added inorganic bromide. Average recovery for all levels studied was 97.12%, and reproducibility was excellent. Sixty-six samples of nonfat dry milk, representing production from various states, were analyzed for natural bromide content by the modified method. Results varied from 12 to 110 ppm.