bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microbiological Assays of Folic Acid Activity in Foods: Changes in Results with Variation of Experimental Conditions and Methods
Authors: Flynn Laura M 
Published: February 2020

Abstract
Data are presented to show the fair correlation between results of microbiological assays with L. casei and results from chick assays. The effects of autoclaving standard solutions of folic acid in phosphate buffers or in potassium ascorbate are shown to be a large decrease in L. casei activity in phosphate solutions but only a relatively small loss in potassium ascorbate. Decreased responses of S. faecalis to extracts containing large concentrations of potassium ascorbate are noted when the organism is grown in the AOAC basal medium for S. faecalis. Microbiological assay data (turbidimetric or titrimetric) should be plotted on a loglog grid to give assurance of an ample incubation period and thus insure a satisfactory assay.
An Improved Screening Method For Chlorinated and Thiophosphate Organic Insecticides in Foods and Feeds
Authors: Samuel Boyd L 
Published: February 2020

Abstract
Three cleanup steps can be used to screen insecticides from crops: preliminary cleanup on a 1″ multiple absorbent column, partition cleanup with hexane-CH3CN, and final cleanup on a 1″ silicic acid-Celite column. Selective elution of the silicic acid column separates the pesticides into groups: a heptachlor degradation product from heptachlor epoxide; aldrin from Kelthane; and DDT, TDE, and Perthane from each other. Test recoveries range from 75 to 100%. Good reproducibility, adequate sensitivity, and freedom from highly critical steps make the method suitable for routine analysis.
Rapid Extraction Procedure for Chlorinated Pesticide Residues in Raw Animal Tissues and Fat and Meat Products
Authors: Onley John H , Bertuzzi Patricia F 
Published: February 2020

Abstract
A rapid procedure has been developed for the extraction of chlorinated pesticide residues from animal tissues and from fats and meat products. The method combines the use of a mixture of acetone, methyl cellosolve, and formamide to extract the pesticide residues, with the use of calcium stearate to coagulate and hold fatty constituents. The per cent recovery ranges were as follows: lindane, 90–108; heptachlor, 80–100; aldrin, 80–100; heptachlor epoxide, 80–108; p,p′-DDT, 76–101; dieldrin, 80–100; and endrin, 80–100. Comparison of results from the described procedure with those from the Mills procedure showed good agreement.
A Gas Chromatographic Column for Pesticide Residue Analysis: Retention Times and Response Data
Authors: Burke Jerry A , Holswade Wendell 
Published: February 2020

Abstract
DC-200 and QF-1 have been combined as the liquid phase in a GLC column to give a different elution of pesticides from the nonpolar methyl silicones now in wide use. The column packing consists of intimately mixed, equal portions of previously coated 80/100 mesh Gas Chrom Q: one portion with 15% QF-1 and the other with 10% DC-200. Operating conditions for a 6 ft × 4 mm i.d. column are as follows: column temperature, 200°C; injection temperature, 225°C; and flow rate, 120 ml N2/min. Relative retention times and response data for electron capture and microcoulometric GLC systems are tabulated for over 85 pesticide chemicals.
Determination of Chlorbenside Residues Including Its Sulfoxide and Sulfone Oxidation Products
Authors: Shuman Harry , Cieri Ugo R 
Published: February 2020

Abstract
A method is presented for determining residues of chlorbenside including its sulfoxide and sulfone oxidation products. The method employs the Mills-Onley-Gaither extraction procedure. Chlorbenside and chlorbenside sulfoxide are converted to chlorbenside sulfone by a short oxidation with chromic-acetic acid solution. Chlorbenside sulfone is isolated from interfering pesticides and most oxidation products on an aluminum oxide column and determined by electron capture gas chromatography. Recoveries for mixtures of the three components added to apple samples at 0.3–5 ppm (calculated as chlorbenside) were between 92 and 110%.
Collaborative Study of a Method for Multiple Chlorinated Pesticide Residues in Nonfatty Vegetables
Authors: Krause Richard T 
Published: February 2020

Abstract
Five laboratories measured aldrin, DDE, and methoxychlor residues in potatoes by electron capture and thin layer chromatography. Average recoveries obtained with the GLC method were 93–103% for the three added pesticides. Each of the five laboratories identified each pesticide correctly and reported reasonable estimates for DDE and methoxychlor by the TLC method. Only one laboratory reported estimates for aldrin by the TLC method. Four laboratories did not achieve complete separation by TLC due to the masking of aldrin by the high levels of DDE.
Determination of Salt in Butter
Authors: Weik Robert W 
Published: February 2020

Abstract
The official AOAC, 15.135, and International Dairy Federation (IDF) methods for determining the salt content of butter have been collaboratively studied. Results indicated that there was no significant difference (P &gt; 0.05) between the method means. A highly significant difference (P &lt; 0.001) was found between laboratory means which reflected individual differences in performing titration procedures and slight deviations from the prescribed procedure. The overall results indicated that the IDF method as studied was as accurate as the longer present official method, and the IDF method is recommended for adoption as official, first action.
Determination of Water in Molasses by the Karl Fischer Method
Authors: Epps E A 
Published: February 2020

Abstract
Collaborative studies were conducted in 1963, 1964, and 1965 to compare the Karl Fischer method with the vacuum drying method (29.008) for determining water in molasses. Results by the Karl Fischer method were in good agreement with known water contents in all studies, and the method is recommended for adoption as official, first action.
Extraction and Estimation of Polycyclic Aromatic Hydrocarbons in Smoked Foods. II. Benzo (a) pyrene
Authors: Howard John W , White Richard H , Fry Bert E , Turicchi Elizabeth W 
Published: February 2020

Abstract
The carcinogen benzo(a)pyrene has been isolated from various smoked foods by modification of the general procedure for polycyclic aromatic hydrocarbons described in Part I. Recoveries of benzo(a)pyrene, added to 75, 100, and 150 g samples of frankfurters, fish, and cheese at levels of 1–2 ppb, ranged from 73 to 100%. Positive identification of the hydrocarbon recovered from feeds at levels as low as 0.02 ppb can be made from its fluorescence spectra.
Rapid Estimation of Recoverable Oil in Citrus Juices by Bromate Titration
Authors: Scott W Clifford , Veldhuis M K 
Published: February 2020

Abstract
A new method has been developed for estimation of recoverable oil in citrus juices, based on quantitative combination in acid solution of d-limonene, the principal component of distilled citrus oils, with bromine. 2-Propanol is added to citrus juice, the mixture is distilled, and the distillate is acidified with HC1 and titrated with potassium bromate-bromide solution. End point is observed by disappearance of color from methyl orange indicator. The distillation requires about 3 min., and complete determination, less than 7 min. Recovery of added d-limonene was 100 ±1%, indicating a high degree of accuracy; replications seldom varied more than 0.001% oil, indicating excellent precision. Recoveries were consistently higher than by the Clevenger method.
Rapid Cleanup Techniques for Chlorinated Pesticide Residues in Milk, Fats, and Oils
Authors: Giuffrida Laura , Bostwick David C , Ives Nathan F 
Published: February 2020

Abstract
A cleanup procedure suitable for analysis of chlorinated hydrocarbon pesticide residues in milk, fats, and oils at the 0.01 ppm level was developed. Acetone removes the milk solids and water from milk. Pesticides are efficiently separated from milk fat and other fats and oils with a small volume of aqueous acetonitrile. The Mills, Onley, & Gaither Florisil technique is used as the final cleanup. The procedure is rapid, and recoveries from fortified samples ranged from 80 to 106%.
Rapid Screening for Some Anticholinesterase Insecticide Residues by Automated Analysis
Authors: Ott Daniel E , Gunther Francis A 
Published: February 2020

Abstract
Various sample preparation methods with two new modifications of a previously reported automated system are presented for the determination of anticholinesterase insecticides. An analyst may select a total set of conditions which may be used as a rapid screening test for the detection of some mammalian toxic organophosphorus pesticide residues in a wide variety of plant material substrates. Suggestions are included for obtaining some degree of specificity, when desired, for certain inhibitors of cholinesterase. Typical summary data from analysis of fortified substrate are as follows: (1) 0.25 ppm DDVP in both broccoli and cauliflower; (2) 0.04 ppm parathion (99.6%) in canned peaches after a manual bromine-water oxidation procedure; (3) 0.1 ppm technical grade parathion in canned peaches and water plants (from wildlife pond); (4) paraoxon and technical grade parathion at 0.4 and 0.5 ppm each in Valencia orange peel; and (5) phosphamidon at 0.1 ppm in both the peel and the pulp of white potatoes.
Gas Chromatographic Determination of Butylated Hydroxyanisole and Butylated Hydroxytoluene in Breakfast Cereals
Authors: Takahashi David M 
Published: February 2020

Abstract
The gas chromatographic method for antioxidants (butylated hydroxyanisole and butylated hydroxytoluene) in corn and rice ready-to-eat breakfast cereals was studied collaboratively. The method employs a column of 80–100 mesh acid-washed Chromosorb P, with a 20% coating of DC-200 silicone oil; an argon ionization detector with a radium source was used. Results were in the 90–110% range, when the instructions were followed exactly. Recoveries ranged between 10 and 180% under conditions deviating from the proposed method. In view of the inconclusive results, it is recommended that the written procedure be revised and that the method be restudied collaboratively.
Analysis of Sunscreens in Suntan Preparations
Authors: Davis Henry M 
Published: February 2020

Abstract
Detailed procedures have been reported for the analysis of 2-ethoxyethyl p-methoxycinnamate, 2-ethylhexyl salicylate, homomenthyl salicylate, and glyceryl monop-aminobenzoate in suntan preparations. Sunscreens were selectively eluted by partition chromatography and identified and determined by ultraviolet spectroscopy. Known amounts of sunscreens added to commercial suntan preparations were successfully recovered. Studies will be continued.
Apparatus for Cold Vapor Atomic Absorption of Mercury
Authors: Schachter Myron M 
Published: February 2020

Abstract
An assembly of optical and electronic modules has been designed to measure submicrogram quantities of mercury in the vapor phase at room temperature. The signal-to-noise ratio is greater than 100 to 1 for 10−2 microgram (5 × 10−1 nanomole) of mercury.
Chemical Determination of Folic Acid in the Presence of p-Aminobenzoic Acid or Procaine Hydrochloride
Authors: Hubbard Willard D , Hintz Mary E , Libby David A 
Published: February 2020

Abstract
The USP XVII chemical method for the determination of folic acid is not applicable to pharmaceutical preparations containing p-aminobenzoic acid (PABA) or procaine hydrochloride (added to intertables to reduce discomfort). PABA is often present in older folic acid injectables in which a breakdown of the folic acid has occurred on long standing. A modified method is described to eliminate interference from these compounds by diazotizing the interfering material and then converting it to the corresponding phenol. The folic acid is then cleaved to form PABA, diazotized, and coupled with the Bratton-Marshall reagent. In a comparison of the two methods using known amounts of folic acid in the presence of PABA, better recovery of folic acid was achieved with the modified method than with the USP method. The application of this modification to commercial preparations is also demonstrated.
Emulsifiers. I. Determination of Mono-, Di-, and Triglycerides in Shortenings by Column Chromatography
Authors: Distler E , Baur F J 
Published: February 2020

Abstract
A method for the quantitative determination of mono-, di-, and triglycerides in shortenings was studied collaboratively. Samples were adsorbed on silica gel columns and the glycerides were separated by benzene, benzene plus 10% ethyl ether, and ethyl ether alone. Eight samples can be run simultaneously with an average standard deviation of 0.1–0.5%. This method is recommended for adoption as official, first action.
Emulsifiers. II. Periodic Acid Analysis for 1-Monoglycerides
Authors: Baur F J , Distler E 
Published: February 2020

Abstract
Two periodic acid analytical methods have been compared for the determination of 1-monoglycerides. A revised Miner procedure is apparently faster and more precise than the official AOCS method, Cd 11-57. The AOCS procedure is recommended for adoption as official, first action. A joint AOAC-AOCS multi-methods study should be conducted to compare the Miner and AOCS procedures.
Study of Moisture, Ash, and Organic Content of Peat Samples
Authors: Thorpe Virginia A 
Published: February 2020

Abstract
An empirical method for determining moisture, mineral, and organic content of peat has been proposed and collaboratively compared with a method similar to that used in Federal specifications for the purchase of peat. Moisture results were significantly low by the Federal method in all cases but generally were equally precise by both methods, indicating that larger samples do not greatly improve the precision. Ash results were about the same for both methods, although the Federal method gave higher precision; ashing conditions in the proposed method appear inconsistent due either to the lower ashing temperature or to the larger sample used. It is recommended that study be continued.
Correlation of Pesticide Polarities with Efficiencies of Milk Extraction Procedures
Authors: Beroza Morton , Bowman Malcolm C 
Published: February 2020

Abstract
Nonpolar pesticides added to milk are adsorbed onto the cream phase and do not penetrate appreciably into the fat globule of the milk. This adsorption results in low recoveries of nonpolar pesticides in extractions with hexane-ether (1:1) carried out immediately after spiking and 5 hours later. Recoveries from raw and pasteurized homogenized milk by an extraction procedure that gives low fat recovery parallel polarities of the pesticides as judged by their extraction p-values. Recoveries by an extraction procedure that gives high fat recovery were satisfactory. With the most polar of the pesticides, recoveries by the extraction procedure giving low fat recovery consistently exceeded those by the procedure giving high fat recovery. Although the data indicate that added pesticides are adsorbed on the fat globule, the nonpolar pesticides may also be bound in the aqueous phase of the milk after removal of the cream.
Assay of Apocarotenal and Canthaxanthin in Foods
Authors: Osadca M , DeRitter E , Bunnell R H 
Published: February 2020

Abstract
Methods are presented for determining the carotenoids β-apo-8′-carotenaI and canthaxanthin in foods to which they have been added as colorants. They are extracted by blending or by shaking with appropriate solvents, depending on the nature of the sample, and are separated from naturally occurring pigments and other added coloring agents by selective solvent extraction and/or column chromatography. Concentration is measured by spectrophotometric reading at the absorption maximum after the system is brought to isomerization equilibrium by treatment with iodine solution. Thin layer chromatographic procedures are described for confirming the identities and completeness of separation of the carotenoids.
Analytical Methods for Diethylstilbestrol in Feeds and Premixes
Authors: Stone Loyal R 
Published: February 2020

Abstract
Methods are presented in which diethylstilbestrol is extracted from feeds in the Goldfisch apparatus, transferred into alkaline sodium acetate solution to avoid emulsions, and measured colorimetrically in a sodium acetate-acetic acid buffer system. The procedure is rapid, and results agree closely with those obtained by the official method. Procedures are also presented for determination of diethylstilbestrol in molasses and fat mixtures.
Single Step Chromatographic Cleanup of Chlorinated Pesticide Residues, Using High Elution Rates
Authors: Moats W A , Kotula A W 
Published: February 2020

Abstract
Single step chromatographic cleanup on partially inactivated Florisil columns and on carbon-Celite columns was carried out with very high elution rates. Elution rates of 250 ml/minute for partially inactivated Florisil did not adversely affect results, and recoveries of insecticides, especially endrin, were improved in some cases. Carbon-Celite columns were eluted at 100 ml/minute without affecting the results. Time required for the chromatographic step was reduced from 45 to 2 minutes for the Florisil and from 2–3 hours to 8 minutes for the carbon-Celite column.
Thin Layer Chromatography of Dinitrophenol Pesticides
Authors: Yip George , Howard Samuel F 
Published: February 2020

Abstract
Four dinitrophenol pesticides, DNOC, DNBP, DNAP, and DNOCHP, can be separated on cellulose thin layer plates, either as the phenols or their methyl ethers. Methyl ethers are prepared by reaction with diazomethane. Partition chromatography between an immobile phase of mineral oil and a mobile aqueous phase gives complete resolution. The compounds are revealed by spraying first with stannous chloride, then with p-dimethylaminobenzaldehyde to yield yellow-orange spots which fluoresce under UV light. The lower limit of detection in the phenolic form varies with the compound, ranging from 0.05 μg for DNOC to 0.3 μg for DNOCHP. The lower limit for the ethers is the same for all compounds, 0.1 pg.
Identification of Alkanolamides by a Methanolysis—GLC Procedure
Authors: Gross F C , Jones J H 
Published: February 2020

Abstract
Fatty acid alkanolamides are converted to the amine and the methyl ester of the fatty acid(s) by refluxing with hydrogen chloride in methanol. The methyl ester (s) and amine are separated by solvent extraction and subsequently identified and/or determined by GLC with the internal standard technique. Recoveries of the methyl esters are substantially quantitative; recoveries of the amines are slightly low but are adequate for positive identification. In the methanolysis of the diethanolamides, products other than the expected amine are produced in detectable amounts.
Use of Detergents in the Analysis of Fibrous Feeds. IV. Determination of Plant Cell-Wall Constituents
Authors: Soest P J Van , Wine R H 
Published: February 2020

Abstract
A rapid procedure for determining cellwall constituents of plants consists of the determination of the fiber insoluble in neutral detergent and is applicable to all feedstuffs. The standardization of the method is based on a nutritional concept which defines fiber as insoluble vegetable matter which is indigestible by proteolytic and diastatic enzymes and which cannot be utilized except by microbial fermentation in the digestive tracts of animals.
The Multi-Determination of Antioxidants in Lard
Authors: Mccaulley Donald F , Fazio Thomas , Howard John W , Diciurcio, Frances M , Ives Julian 
Published: February 2020

Abstract
A method has been developed for the multiple determination of antioxidants (BHA, BHT, Ionox-100, PG, THBP, and TDPA) in lard. The procedure consists of vacuum sublimation of the antioxidants and quantitative determination by gas chromatography. UV, IR, and mass spectrometry were used for identification and confirmation. Average recoveries of the antioxidants added to 4 g lard at 100 ppm ranged from 91 to 96%
Extraction of Lipids from Raw Beef Lean by Using Various
Solvent Systems
Authors: Hagan Susie N , Murphy Elizabeth W , Shelley Lydia M 
Published: February 2020

Abstract
Study shows that chloroform-methanol extraction to remove lipids from beef yielded percentages of total fat equal to or greater than those obtained by the AOAC method. The ratio of phospholipid to triglyceride was always higher in the chloroform-methanol extracted samples. Six extraction methodsolvent system combinations, three drying procedures, and two sample preparation methods were compared. Tlie extracted lipids were separated by thin layer chromatography. The ratio of phospholipid to triglyceride was calculated after the spectrophotometric determination of the ester groups present. Acid-hydrolysis-Rohrig gave the lowest yield of total lipid and of phospholipid. Sample preparation method or drying method caused few significant dif. ferenccs in the proportions of total solids and of total lipids in the beef cuts analyzed
A Study of the Net Weight and Drained Weight Relationship
of Frozen Shrimp Products
Authors: Werren J C , Johnson Arthur R , Weik R W 
Published: February 2020

Abstract
A collaborative study was made of a disk acrylamide gel electrophoresis method for identifying fish species through the use of characteristic protein bands. Results were generally satisfactory; 6 of 7 collaborators agreed on all samples. It is recommended that the method be adopted as official, first action
Determination of Aldehydes in Wines by the Direct Bisulfite
Method: American Society of Enologists—AOAC Joint Report
Authors: Guymon James F , Wright Dawson L 
Published: February 2020

Abstract
A collaborative study was made on the Guymon and Crowcll direct bisulfite determination of aldehydes in wine in cooperation with a committee of the American Society of Enologists. The method is based upon the reaction of the aldehydes with an excess of bisulfite solution at a neutral pH, removal of the excess bisulfite by iodine in acid medium, and direct titration with standard 0.05/V iodine of the bisulfite released in alkaline medium. The mean values for aldehydes found in 4 wines by 9 collaborators gave standard deviations of 2,7-4.5% of the mean. The method determines free aldehydes plus aldehydes bound with bisulfites existing in wines, while it excludes acetals which account for only 1-3% of the aldehydes present. The method gives a very satisfactory degree of precision and accuracy and is recommended for adoption as official, first action
Quantitative Determination of Benzaldehyde in Flavors and Cordials by Ultraviolet Spectrophotometry and 2,4-Dinitrophenylhydrazine Precipitation
Authors: Brunelle Richard L 
Published: February 2020

Abstract
Three sets of samples were collaboratively analyzed by the official, first action ultraviolet spectrophotometric and 2,4-dinitrophenylhydrazine precipitation methods for determining benzaldehyde in flavors and cordials. The spectrophotometric method was unchanged, except for clarification, and collaborators reported recoveries averaging nearly 100%. The gravimetric procedure using 2,4-dinitrophenylhydrazine gave unsatisfactory recoveries on the first two sets of collaborative samples. However, collaborators reported approximately 96% recovery of benzaldehyde with a modified precipitation procedure on a third set of samples. The ultraviolet spectrophotometric method and the modified 2,4-dinitrophenylhydrazine precipitation procedure are recommended for adoption as official, final action as alternative methods.