bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of Calcium and Magnesium in Fertilizers by EDTA Titrations: A Collaborative Study
Authors: Smith John B , Manning Peter B 
Published: February 2020

Abstract
Collaborative analyses of nine fertilizers by eight analysts at seven laboratories demonstrated that the EDTA method for magnesium is equally accurate and more precise when compared with the longer official methods. Neither the EDTA method nor official method 2.085 was satisfactory for all samples. The EDTA method for magnesium will not tolerate more than 0.25% of manganese or zinc.
Effect of Extraction Time on Citrate-Insoluble P2O5 Content of Fertilizer
Authors: Gehrke Charles W , Kramer George H 
Published: February 2020

Abstract
Twenty-four commercial fertilizers representing different types and grades and different manufacturing processes were used to evaluate the effect on CI P2O5 of digestion time at 65°C with continuous agitation. The data show that for mixed fertilizers and straight materials, all water and citrate-soluble phosphorus was extracted within 60 minutes of digestion, with two exceptions: Further solubilization of CI P2Os occurred in samples of tricalcium phosphate and ammoniated triple superphosphate samples for digestion times of 2— 3 hours.
Determination of Pentaerythritol Tetranitrate in the Presence of Meprobamate
Authors: Rosenstein Jack 
Published: February 2020

Abstract
Use of phenoldisulfonic acid was found to be applicable to pentaerythritol tetranitrate determination with or without meprobamate being present. Recoveries from collaborative samples with or without meprobamate were 100 £ 3% of the theoretical amount.
Determination of Choline in Feeds
Authors: Lim F , Schall E D 
Published: February 2020

Abstract
The "free" and "bound" forms of choline were determined in feeds by a rapid method in which extraction and hydrolysis were accomplished simultaneously with a barium hydroxidemethanol-chloroform mixture. The choline was isolated from the hydrolysate by adsorption on a Florisil column. Passing ammonium reineckate through the column formed the choline reineckate which appeared as a pink band after excess reagent was washed out. The concentration of the choline was determined by eluting the reineckate band and measuring the absorbance at 526 mμ. Recoveries of added choline ranged from 98.9 to 100.8%.
Basic Feed Microscopy
Authors: Smith C Tyson 
Published: February 2020

Abstract
Collaborative results are presented on a basic procedvire for feed microscopy using either the stereoscopic or high power microscope to identify vegetable tissues, animal tissues, and major mineral constituents. A poultry grower mash and a dairy concentrate were studied; each sample contained ingredients conforming to the definitions of the Association of American Feed Control Officials. The identifications of the unknown ingredients by the collaborators were reasonably reliable, and the method is recommended for adoption as official, first action.
Collaborative Study of Colorimetric Methods for Phosphorus in Feeds
Authors: Heckman Mary 
Published: February 2020

Abstract
Six feed samples of varying phosphorus content and with calcium/phosphorus ratios of 0.5— 2.0 were distributed. Eleven laboratories compared the official volumetric method (22.061) with the molybdenum blue method studied in 1962. Twelve laboratories compared 22.061 with Parks and Dunn's colorimetric molybdovanadate method now used for fertilizers. Means for all methods show excellent agreement. Statistical analysis by Youden's formula shows marked superiority of the molybdovanadate method over the molybdenum blue method.
Rapid Infrared Method for Toxaphene in Animal Dips and Sprays
Authors: Czech Fred P 
Published: February 2020

Abstract
An infrared spectrophotometric method has been developed for the determination of toxaphene in aqueous emulsions used for the eradication of ectoparasites in livestock. The active ingredient is "salted-out" of emulsion with sodium chloride and extracted with carbon tetrachloride, and an infrared spectrum is taken of the latter extract. Toxaphene concentration is obtained from its characteristic absorption peak at 1303 cm-1 by the baseline method. The infrared method has the advantages of speed, simplicity, and, especially, specificity over chemical procedures.
Enzymatic Determination of Carbon Dioxide in Lightly Carbonated Wine—1963 Collaborative Study
Authors: Morrison Robert L 
Published: February 2020

Abstract
The titrimetric method for determining carbon dioxide in wine, using carbonic anhydrase, was studied collaboratively for the second year. Sample preparation was improved, and two modifications were made in the apparatus: a 5 ml instead of a 10 ml buret and a 25—30 ml automatic pipet instead of a 50 ml buret. Results were good, and it is recommended that the method be adopted as official, first action.
Quantitative Methods for Trace Amounts of Polyvinylpyrrolidone
Authors: Shiraeff D A 
Published: February 2020

Abstract
Two approaches were used for a simple procedure for quantitative estimation of polyvinylpyrrolidone: I. PVP forms complexes with textile dyes, which can be identified by paper chromatography. When PVP is added to a chromatographing solvent, the spread of a spot of dye placed on a paper strip is a function of PVP concentration in the solvent. Pyramine Orange 2R and Congo Red were used in the test. II. At concentrations of perchloric acid greater than 1.6-1.7%, PVP falls out of solution and forms a finely dispersed precipitate like a cloud. The clouding is proportional to PVP concentration and can be measured by a nephelometer or spectrophotometer.
Removal of Urea from Corn by the Steeping Process of Wet Corn Milling
Authors: Nicholson J F , Harris Kenton L 
Published: February 2020

Abstract
To test the removal of urine from corn by the corn steeping process, urea containing C-14 was added to corn in four different ways. Radiation present after steeping demonstrated that some of the added C-14 remained in the corn, indicating that some urine persists through the corn steeping process. When added to the insect exit hole, the greatest amount remained unremoved by steeping (average of 2.9%). Amounts above radiation normal to leached corn (0.2 counts/min.) also remained in one instance when the radioactive urea was placed on the endosperm and in one or two instances when it was allowed to enter at the germ end.
Assay of Oil-Soluble Vitamins. Part I. Vitamin A and Carotene: Suggestions for Improving Assay
Authors: Deutsch M J , Jones S W , Wilkie J B , Duffy D , Loy H W 
Published: February 2020

Abstract
The adaptation of official methods to the assay of vitamin A in many commercial products has required modifications in the apparatus used and improvements in assay techniques. These modifications increased the number of routine samples that are screened per day from three to eight, with a corresponding increase in per cent recovery and degree of reproducibility. The most important modifications were installation of equipment to permit handling of more samples at a time, changes in volumes and concentrations of solutions to improve separations, and use of an internal standard in the antimony trichloride method for the assay of vitamin A.
Collaborative Study of Microbiological Assay for Folic Acid in Food
Authors: Flynn Laura M 
Published: February 2020

Abstract
The extraction and microbiological determination of folic acid in foods was studied collaboratively. Four samples and four extraction procedures were used. Extracts were assayed for folic acid activity with L. casei and S. faecalis, and chick assays were also made on the samples. The four extraction procedures were: (A) Incubating 4 hours with chick pancreas at 37 °C after autoclaving 15 min. at 15 lb in 0.2M pH 7.2 phosphate buffer and cooling; (B) autoclaving 30 min. at 15 lb in potassium ascorbate (pH 6.0, 6 mg/ml); (C) incubating 4 hours with chick pancreas enzyme after autoclaving 15 min. at 15 lb in 0.2M pH 8 phosphate buffer, cooling, and adding potassium ascorbate (20 mg/ml, pH 6) in volume equal to the phosphate buffer; and (D) autolyzing in incubator 4 hours at 37 °C in mixture of equal volumes of potassium ascorbate (20 mg/ml, pH 6) and 0.2M phosphate buffer, pH 8.0. The highest values were obtained with L. casei in extracts containing potassium ascorbate. A rough estimation of the types of folic acid derivative in each extract could be made by comparing values obtained in the various extracts with each organism. Collaborators’ results by chick assay agreed fairly well with those by microbiological assay, but further work is needed to standardize the extractions and both types of assays.
Analysis of Insecticides in Aqueous Emulsions Used in Livestock Dips and Sprays: General Infrared Method
Authors: Czech Fred P 
Published: February 2020

Abstract
An infrared spectrophotometry method can be widely applied as a general procedure for analysis of insecticides in aqueous emulsions used to eradicate ectoparasites in livestock. Analytical procedures are given for Delnav, Ciodrin, lindane, and toxaphene-lindane mixture. The method is rapid, simple, precise, versatile, generally free from interference, and unequivocally specific. It is recommended as a universal first approach to analysis of insecticides in animal dip and spray emulsions.
A Simple Method for the Detection of Benzo[a]pyrene in Smoked Foods
Authors: Genest C , Smith D M 
Published: February 2020

Abstract
Benzo[a]pyrene can be used as an index of carcinogens in smoke. A simple and rapid method has been developed for determining this substance. The dried food was extracted with ra-hexane, the hexane was then extracted with dimethyl sulfoxide, and the polynuclear hydrocarbon was displaced from this solvent into benzene by water. The benzene extract was reduced to a small volume and an aliquot was spotted on a thin-layer chromatographic plate beside spots of a standard benzo[a]pyrene solution. The plate was chroma tographed with 2,2,4-trimethyl pentane:benzene (97:3). When observed under ultraviolet light at 3660 Å, 0.002 μg of pure benzo[a]pyrene could be found and the addition of 0.01—0.05 ppm to unsmoked foods could be detected. No smoked food examined contained this level of benzo-[a]pyrene.
An Improved Ammonium Molybdophosphate Method for Phosphorus in Fertilizers
Authors: Brabson J A , Johnson F J , WILLIARD J W , Burch W G 
Published: February 2020

Abstract
The official volumetric method for phosphorus in fertilizers was modified to improve its accuracy and precision. Sulfate interference is eliminated by addition of excess nitric acid before precipitation of the molybdophosphate. The precipitate is filtered on a glassfiber pad, and when it is dissolved in alkali, formaldehyde is added to complex the ammonia; a mixed indicator (methyl green-phenolphthalein) is used that changes color at the equivalence point. The modified method passed Youden’s ruggedness test and gave results in excellent agreement with those of the gravimetric quinolinium method in analyses of standard phosphate rocks, primary phosphate standards, and fertilizers.
A Preliminary Investigation Into the Quantitative Determination of Organophosphorus Pesticide Residues by Conversion to Orthophosphate Ion
Authors: Getz Melvin E 
Published: February 2020

Abstract
Organophosphate pesticides are converted to orthophosphate ion, by reaction with a dilute solution of ammonium persulfate. This method shortens the reaction time and eliminates the handling of strong acids necessary for conventional digestion procedures; 0.1 μg of P is detected, which is equivalent to approximately 1 μg of pesticide.
Colorimetric Determination of Residues of the Dithiolane Insecticides in Cottonseed and on Cotton Foliage
Authors: Blinn Roger C , Boyd John E 
Published: February 2020

Abstract
A colorimetric procedure has been devised to determine residues of the dithiolane insecticides, 2-diethoxyphos-phinothioylimino-1,3-dithiolane (I) and 2-diethoxyphosphinylimino-1,3-dithiolane (II), in cottonseed and on cotton foliage. The chromogenic reaction is based on the acid hydrolysis of the dithiolane insecticides to 2-imino-1,3-dithiolane, which is converted by treatment with alkali to thiocyanate. The thiocyanate is converted to cyanogen bromide and then reacted with benzidine-in-pyridine solution to form an intense red solution with absorbance maximum at 530 mμ. Recoveries of I and 11 from cottonseed averaged 83 ± 5% and 68 ± 4% in the range 0.1-1 ppm, with background values of 0.04 ± 0.01 ppm; recoveries from cotton foliage averaged 79 ± 7% and 84 ± 7%, respectively, for I and II, with background values of 0.02 ± 0.01 ppm.
Quantitative Determination of Vanillin and Ethyl Vanillin in Flavors by Paper Chromatography
Authors: Fitelson J 
Published: February 2020

Abstract
Previous methods for estimating vanillin and ethyl vanillin in mixtures were long and complicated. However, this paper presents a simple chromatographic separation and quantitative determination of these aromatics, using Mitchell equipment for paper chromatography and 8 × 8” papers. Development for 2 hours separates the compounds adequately; they are then extracted and measured by absorbances at 348 mμ in alkaline solution. Recoveries of added vanillin and ethyl vanillin to vanilla extract are excellent. Aside from normal manipulative errors, the only significant inaccuracy is caused by the small amount of natural p-hy-droxybenzaldehyde in vanilla (usually equivalent to about 5% of the vanillin content). The method does not separate p-hydroxybenzaldehyde and vanillin. Total errors in the method do not exceed 0.01%. Comparison of the method with the two AOAC methods for vanillin shows that the paper chromatographic method gives results close to those by the ultraviolet absorption method, in most cases, and significantly lower results than the photometric method, which is known to give erroneously high results.
Ultraviolet Spectrophotometric Method for Ronnel in Feeds
Authors: Gehrt Albert J 
Published: February 2020

Abstract
The ultraviolet spectrophotometric method for Ronnel in feed mixtures, presented at the 1963 AOAC meeting, was studied further at levels of 0.015–0.6% Ronnel by 10 collaborators to test the accuracy and reproducibility of the method by vising reagents free from abnormal ultraviolet absorbance. The variety of feed ingredients was increased to include milo, barley, and alfalfa in addition to those used in the 1963 study. Ronnel is extracted from the sample with methanol-petroleum ether and hydrolyzed to the 2,4,5-trichlorophenate. After solvent evaporation, the residue is dissolved in water, the pH is adjusted and buffered at 7.0, calcium chloride solution is added, and the mixture is steam distilled. The 2,4,5-trichlorophenol in the steam distillate is extracted with iso-octane and measured spectrophotometrically. All collaborators obtained good results; therefore, the Associate Referee recommends that the method be adopted as official, first action. Experimental studies showed that 2,4,5-trichlorophenol can be separated from Ronnel by ion exchange. This will be studied collaboratively next year.
Extraction and Estimation of Polycyclic Aromatic Hydrocarbons Added to Milk
Authors: Howard John W , Teague Robert T 
Published: February 2020

Abstract
Polycyclic aromatic hydrocarbons added to milk are extracted directly from the milk with a hydrocarbon solvent under alkaline conditions. A partition step between the hydrocarbon solvent and dimethyl sulfoxide, followed by paper chromatography, is then employed to reduce interfering background material extracted from the milk. Ultraviolet spectral analysis is used to estimate the type and concentration of polycyclic compounds. Recoveries of 8 polynuclear hydrocarbons, added to one pint of milk at levels of about 2 and 4 ppb, ranged from 63 to 90%.
Determination of Minor Nutrients in Fertilizers by Atomic Absorption Spectrophotometry
Authors: McBride C H 
Published: February 2020

Abstract
A general atomic absorption spectrophotometric method for the determination of copper, iron, magnesium, manganese, and zinc in commercial fertilizers and raw materials is presented. The method has been subjected to ruggedness and collaborative tests and is shown to be simple, rapid, and acceptably precise. Its adoption as official, first action is recommended.
Determination of Cobalt in Fertilizers
Authors: Hodgson J F , Lazar Victor A 
Published: February 2020

Abstract
Cobalt in fertilizers was determined by a colorimetric method using 2-nitroso-l-naphthol. With this method the fertilizer is digested with a ternary acid mixture; cobalt is then extracted from a suitable aliquot into isoamyl acetate at pH 8.5 with an excess of 2-nitroso-l-naphthol. Excess dye and interferences are removed by successive washes with acid and base. A limited number of collaborator analyses indicate that agreement of results is not as satisfactory as might be expected with the major fertilizer constituents. However, collaborator agreement compares favorably with other methods of analyses accepted by the AOAC for Co. While the procedure is considered tedious by some collaborators, it is believed to be less tedious and less subject to interferences than other colorimetric methods available.
Evaluation of Methods for Identifying Fatty Acid Esters Separated by Gas Chromatography
Authors: Iverson John L , Firestone David , Eisner Jerome 
Published: February 2020

Abstract
Correct identification of component fatty acids is frequently difficult when determining fatty acid composition by the AOCS-AOAC gas chromatographic method. Fats and oils that contain a large number of components, such as butter, peanut, and marine oils, are particularly troublesome. The usefulness and limitations of (a) isothermal semilogarithmic plots, (b) retention time ratios, (c) programmed temperature semilogarithmic plots, and (d) variation of retention time with temperature are evaluated.
Fractionation of the Color of Pure Maple and Other Sirups by Gel Filtration
Authors: Stinson E E , Willits C O 
Published: February 2020

Abstract
The colorants of pure maple, cane and maple, refined cane sugar, and light brown sugar sirups were separated into two fractions, one of high- and the other of lowmolecular weights, by means of gel filtration.
The ratio of the amounts of high- to the low-molecular weight fractions of pure maple was the lowest of the four sirups and serves as a means of differentiation from these sirups. The color fraction ratio was highest for blended cane-maple sugar sirup.
Many maple sirups are also distinguished by a pink band formed on the gel filtration column.
Comparison of Methods for the Determination of Vanillin in Vanilla Extract
Authors: Smith D Morison 
Published: February 2020

Abstract
Vanillin was determined in vanilla extracts by standard colorimetric and ultraviolet spectrophotometric procedures. A comparison of the results by these methods and an assessment of the probable interferences led to the development of a new UV spectrophotometric method. This procedure is based vipon the difference in absorbance between alkaline and neutral solutions of the vanilla and can, by the use of a suitable equation, be used to determine both the vanillin and p-hydroxybenzaldehyde concentrations.
Determination of Fly Eggs and Maggots in Tomatoes and Tomato Products
Authors: Coulter Earl W 
Published: February 2020

Abstract
A sieving method has been developed to improve insect fragment recovery and reduce the percentage of eggs recovered without process from tomatoes and tomato products. The method is rapid, requires no specialized equipment, and uses an inexpensive and readily available reagent. Residues of all types of tomato products can be counted on one cloth. The method is adaptable to large samples. It is recommended that the sieving method be studied collaboratively.
UV Determination of Sulfoxide in Formulations
Authors: Haus J B , Manolev L , Price R W 
Published: February 2020

Abstract
A method for the assay of sulfoxide in insectieidal formulations involves separation of the sulfoxide from the other components by column chromatography on silicic acid with three successive eluting solutions: chloroform; 2% acetone in chloroform; and 10% acetone in chloroform. Sulfoxide is removed in the last eluate and is determined by ultraviolet spectrophotometry. Solvents, emulsifiers, pyrethrins, compounds related to sulfoxide, and other insecticides tested are separated by the column.
Sampling Commercial Feeds
Authors: Spruill C K 
Published: February 2020

Abstract
To determine if the accuracy of a sample is changed by taking 10 cores instead of 20 cores, a study was made of 260 samples of 10 cores and of 20 cores of bulk commercial feed, representing 130 different rail car loads. Very little difference was found in the protein, fat, and fiber content between the two sampling sizes. Based on the study, it is recommended that the official sampling procedure be amended to specify that at least 10 cores from different regions be collected in sampling bulk feeds.
Rapid Digestion and Cleanup of Animal Tissues for Pesticide Residue Analysis
Authors: Stanley Ronald L , LeFavoure Herbert T 
Published: February 2020

Abstract
A method is presented for the rapid digestion and cleanup of animal tissues for pesticide residue analysis. Animal tissues are digested by a perchloric-acetic acid mixture to destroy the cellular structure and quantitatively liberate the pesticide-containing fat. The fat is extracted in n-hexane and destroyed on a sulfuric acid-Celite column. The common chlorinated pesticides (except aldrin, dieldrin, and endrin) can then be determined by a colorimetric or chromatographic procedure.
Microanalytical Determination of Bromine, Chlorine, and Iodine by Oxygen Flask Combustion
Authors: Steyermark Al 
Published: February 2020

Abstract
Thirty collaborators participated in a study of the use of oxygen flask combustion for the microdeterminations of bromine, chlorine, and iodine in organic compounds. Generally, there was little difference in the precision of the various methods. Argentometric titration gave better results than did iodometric titration only in the case of bromine. The use of hydrazine sulfate gave better results in the case of iodine than when it was omitted; the same held true for hydrogen peroxide. It is recommended that the study be continued.
Ion Exchange Resin Separation and Flame Photometric Determination of Sodium, Potassium, Magnesium, Calcium, and Strontium
Authors: Breault Eugene A 
Published: February 2020

Abstract
The cation exchange separation of metallic chlorides by hydrochloric acid on an Amberlite CG-120 resin (200-400 mesh) column was investigated. Commercially available resin was used in the experiments after the “fines” were removed by several water washings. A resin column (24 cm long by 12 mm diameter) gave excellent separation of sodium and potassium, with a total volume of 500 ml of 0.5N HCI at a flow rate of 0.55 ml/min. The recovery of each metal was 100%. Elution of the other three metals required 1100 ml of liV HCl; separation was very good but recoveries were poor. AH of the metals were determined with a Beckman DU with photomultiplier and hydrogen-oxygen flame attachment.
Thin-Layer Chromatographic Determination of Carbaryl (Sevin) in Some Foods
Authors: Finocchiaro Josephine M , Benson Walter R 
Published: February 2020

Abstract
A thin-layer chromatographic method is described for the semiquantitative determination of the insecticide carbaryl. Acceptable recoveries ranging from 0.05 to 0.2 ppm have been obtained from nine crops. The Rf value of carbaryl ranged from 0.52 to 0.60 on aluminum oxide G plates.