bluuebunny/crossref_metadata_2025_split huggingface dataset:
Atomic Absorption Adaptation of the Quinolinium Molybdophosphate Method for Phosphorus
Authors: Melton James R , Hoover William L , Howard Peggy A , Green Vera S 
Published: February 2020

Abstract
A method employing a modification of the quinolinium molybdophosphate method is proposed whereby total phosphorus may be indirectly determined by atomic absorption of molybdenum. Only routine instrumentation procedures are required. The official gravimetric method is followed until the quinolinium molybdophosphate precipitate is formed. The precipitate is dissolved in NH4OH, and molybdenum is determined by atomic absorption. Phosphorus analyses of Magruder collaborative fertilizer samples determined by the AOAC and proposed methods compare favorably.
Semiquantitative Determination of Polychlorinated Biphenyls in Tissue Samples by Thin Layer Chromatography
Authors: Mulhern Bernard M , Cromartie Eugene , Reichel William L , Belisle Andre A 
Published: February 2020

Abstract
A method is described for the analysis of polychlorinated biphenyl (PCB) compounds in tissue samples. Cleanup by hexane-acetonitrile partitioning and Florisil column chromatography are performed on samples before oxidative treatment to convert DDE to DCBP. PCB components are then determined semi-quantitatively by TLC. No prior separation of PCB from chlorinated pesticides is required. The lower limit of sensitivity is 0.2 μg.
Semiautomated Liquid Chromatographic Determination of Clopidol in Poultry Feed
Authors: Skelly N E , Cornier R F 
Published: February 2020

Abstract
A semiautomated ion exchange-ultraviolet procedure has been developed for the determination of clopidol in poultry feed at the 40–250 ppm level. A methanol extract of the feed is injected into an alumina precolumn to remove interferences. The clopidol passes through the alumina column and is collected on an ion exchange column. With a specially designed elution apparatus the clopidol is removed by an acetic acid-methanol gradient. The eluate proceeds through a flowcell mounted in an ultraviolet spectrophotometer. Response of the spectrophotometer is monitored by a recorder. Concentration is determined by comparing the peak area in the resulting chromatogram with that of a standard. Accuracy and precision of this method are ±5% relative to the amount present (100±5 ppm).
An Alternative Method for Dispersing Cocoa Press Cake Prior to Light Filth Analysis
Authors: Brickey Paris M , Gecan John S 
Published: February 2020

Abstract
A rapid alternative method has been developed for dispersing cocoa press cake in preparation for light fdth analysis. The press cake is broken into pieces one-half inch or smaller and mechanically stirred in hot (150°C) peanut oil for dispersion prior to defatting with Triton X-114. Light filth is then determined by method 40.006(a). Intralaboratory studies proved the method to be faster than the existing dispersion procedures and to result in almost twice the recovery of rodent hairs. Recoveries of insect fragments were not affected. The method has been adopted as an alternative to dispersion techniques in 40.006(c).
Collaborative Study of a New Method for the Extraction of Light Filth from Water-Insoluble Candies
Authors: Gecan John S 
Published: February 2020

Abstract
A new method has been developed for the extraction of light filth from candies containing water-insoluble ingredients. The candy is dispersed and defatted with a synthetic detergent, wet sieved, deaerated, and extracted with either mineral oil or a mineral oil-heptane mixture from either hot or cooled 40% isopropanol. Collaborative study demonstrated that the new method gives better and more reproducible light filth recoveries and cleaner extraction papers than the official AOAC method. The method has been adopted as official first action to replace 40.081(c).
Collaborative Study of a New Method for Extraction of Light Filth from Reconditioned (Coarsely Ground) Nutmeg
Authors: Vazquez Alberto W 
Published: February 2020

Abstract
A new method has been developed for extraction of light filth from coarsely ground nutmeg. Nutmeg tissue is defatted by 3 successive 10 min extractions with boiling CHCI3, after which the solvent is removed by aspiration and an isopropanol rinse. Following sieving on a No. 230 sieve and a brief deaeration and hydrolysis step in acidified boiling 60% ethanol-CaCl2, light filth elements are extracted with mineral oil from the 60% ethanol-CaCl2 mixture. Collaborative testing of the proposed method yielded satisfactory recoveries of added light filth elements. The official method for ground spices, 40.106(b), was compared in a collaborative study with the proposed method for the analysis of ground nutmeg and mace. Results were encouraging, but further study is indicated. The method as described for reconditioned nutmeg has been adopted as official first action.
Collaborative Study of the Determination of Menadione Sodium Bisulfite in Injections
Authors: Johnson Roger D 
Published: February 2020

Abstract
A chromatographic-UV spectrophotometric method for the determination of menadione sodium bisulfite was subjected to a collaborative study. A sample of the injection is mixed with Celite and placed on a chromatographic column. The column is washed with chloroform; the menadione is eluted with an ammonia-saturated chloroform solution and determined by measuring UV absorbance at 334 nm. Four synthetic sample solutions were sent to 13 collaborators for analysis. The average recoveries of these solutions ranged from 97.5 to 98.4% of added amount and had coefficients of variation ranging from 1.1 to 1.4%. The method has been adopted as official first action.
Detection of Animal Fats in Vegetable Fats and Oils by GLC and TLC
Authors: Thorpe Charles W 
Published: February 2020

Abstract
Three methods which employ digitonin precipitation to isolate sterols were tested to determine the extent to which the digitonides were formed at 3 different mole ratios of digitonin to cholesterol. The effect of added aluminum chloride was also studied. Small amounts of added aluminum chloride reduced the amount of non-complexed cholesterol found by each of the methods studied; however, a minimum weight ratio of 10:1 digitonin to cholesterol is necessary for quantitative work. Two types of commercially available precoated thin layer chromatographic plates were evaluated for use in the present AOAC method for determining animal fats in vegetable fats and oils, 28.018–28.088. Commercial plates were tested with samples identical to those used in the 1969 collaborative study of this method. Results indicate that these commercial plates are acceptable in that they adequately separate sterols from other unsaponifiable components. The official first action method has been revised to permit optional use of these plates.
Collaborative Study of a Gas Chromatographic Method for the Analysis of Diazinon
Authors: Murphy R T , Hofberg A H , Buser H R 
Published: February 2020

Abstract
A gas chromatographic method for the determination of Diazinon in liquid formulations containing about 50% active ingredient was collaboratively studied, using a matched pair scheme. The sample was dissolved in acetone containing aldrin as an internal standard and chromatographed on silicone DC-200, using a flame ionization detector. Determinations on the 2 samples by 18 collaborators using peak height measurements show an overall coefficient of variation of 1.0%. The coefficient of variation of random error is 0.8%, and for the systematic error, 0.4%. Application of the F-test proved this systematic error not to be significant. The method has been adopted as official first action.
Gas Chromatographic Determination of N-Butyl-N-ethyl-α,α,α-trifluoro-2,6-dinitro-p-toluidine and α,α,α-Trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine in Formulations
Authors: Fuzesi Martha 
Published: February 2020

Abstract
A gas chromatographic method is described for the quantitative determination of N-butyl-N-ethyl-α,α,α-trifluoro-2,6-dinitro-p-tolindine and α,α,α-trifluoro-2,6-dinitro-N,N-dipropyI-p-toluidine herbicides in formulations. The sample is extracted with benzene, and equal amounts of sample and reference solution in the same concentration range are analyzed by gas chromatography, using an electron capture detector and an SE-30/Diatoport S column. The method has been applied successfully to laboratory-prepared and commercial samples.
Reaction Conditions Necessary for Silylation of Herbicides
Authors: Baur J R , Baker R D , Davis F S 
Published: February 2020

Abstract
The reaction conditions are described for preparation and gas chromatographic analysis of microgram quantities of the trimethylsilyl (TMS) esters of 3,6-dichloro-o-anisic acid (dicamba), (2,4-dichlorophenoxy)acetic acid (2,4-D), (2,4,5-trichlorophenoxy)acetic acid (2,-4.5-T), and 2 water-degradable polymers of 2,4,5-T. Silylation was efficient at 0, 22, and 55°C. A ratio of 1:10 silylating agent (N,O-bis-(trimethylsilyl)acetamide, BSA) to silylation solvent (dimethylformamide, DMF) was optimum for silylation of 2,4-D, 2,4,5-T, and 2,4,5-T polymers. A 1:50 ratio was best for silylation of dicamba. A 1:10 ratio (BSA/DMF) will tolerate up to 1.0 and 0.1% water in the silylation of 2,4-D and 2,4,5-T, respectively. A 1:50 ratio will tolerate up to 0.1% water in the silylation of dicamba. Silylated samples could be analyzed immediately after addition of the silylation reagent. Stability of silylated samples at 22°C was directly proportional to concentration; 1.0 μg samples showed no loss of activity 2.3 hr after reaction. TMS esters were chromatographed on a 6′ × ¼″ glass column containing 3% SE-30 on 80-100 mesh Chromosorb W(HP) at 230°C.
Media to Improve Flagellar Development for Salmonella Flagellar (H) Test
Authors: Poelma P L , Romero A 
Published: February 2020

Abstract
An increasing number of salmonellae, isolated and examined in 1969, failed to give a positive flagellar (H) reaction upon initial testing. After passage through motility medium, the majority of these cultures were positive when retested using the AOAC Salmonella serological flagellar test procedures. Improved detection of flagellar antigens was obtained by using a medium consisting of equal portions of Trypticase Soy and tryptose broths and a small amount of yeast extract. The improvement in the flagellar agglutination test usually occurred without passing the culture through motility medium. The substitution of the improved flagellar broth for tryptophane broth in the AOAC 24 hr Salmonella polyvalent, 41.039, or Spicer-Edwards flagellar, 41.040, tests has been adopted.
Amino Acid Composition of Food Proteins: Inter- and Intralaboratory Variation
Authors: Knipfel J E , Aitken J R , Hill D C , McDonald B E , Owen B D 
Published: February 2020

Abstract
Inter- and intralaboratory variation in amino acid composition of casein, soy flour, and fish flour was examined for 5 cooperating laboratories, utilizing ion exchange chromatographic analyses for amino acids. Duplicate analyses within laboratories exhibited coefficients of variation of 3.7 to 4.4%. Hydrolysis was observed to affect amino acid recoveries to a significant degree, with some amino acids affected to greater extents than others. Laboratories utilizing Moore-Stein type analytical procedures did not appear to be more precise than those using the Piez-Morris method. Adjustment of data to constant total recovery values reduced interlaboratory variation considerably and suggested that recovery constants may be of value in comparing data from different laboratories. Results indicated that different laboratories employing varying analytical procedures may produce practically identical results from a standard sample, although variation may be observed due to characteristics of a specific system. Most variation in results was likely due to sample manipulations rather than to analysis per se.
Collaborative Study of a Modified Method for the Determination of Aflatoxins in Copra, Copra Meal, and Coconut
Authors: Baur F J , Armstrong J C 
Published: February 2020

Abstract
A collaborative study, in which 19 laboratories participated, was conducted on a modified method for the determination of aflatoxins in 2 copra samples, one naturally contaminated, and 4 samples of naturally contaminated copra meal. The sensitivity and precision of the modified method for aflatoxin B1 and total aflatoxins were comparable to the official methods for peanuts and peanut products. Aflatoxins B2, G1, and G2 were reported by most of the laboratories, but background interferences made quantitative measurement less reliable than for B1. The method as it presently stands is also applicable to the analysis of coconut. The method has been adopted as official first action; further study will be directed toward improved precision for analysis of aflatoxins B2, G1, and G2.
Analysis of Radiopharmaceuticals
Authors: Jaffee Max , Ford Leonard 
Published: February 2020

Abstract
Some of the activities of chemists engaged in evaluating and selecting analytical methodology for examination of radiopharmaceuticals and the criteria for assessment of their quality are described. Significant problems, as they relate to a regulatory analysis program, and tentative solutions to these problems are discussed. Conclusions and recommendations, based on the results of analysis of selected radiopharmaceutical preparations of commercial origin, are given.
Collaborative Study of the Analysis of Acetaminophen and Salicylamide in Tablets and Capsules
Authors: Hamilton James L 
Published: February 2020

Abstract
A column chromatographic procedure has been developed for separating acetaminophen and salicylamide in combination with a variety of other drug ingredients in tablets and capsules. Strongly acidic and basic Celite columns are used to trap acetaminophen and salicylamide, respectively. Quantitation is performed using UV spectrophotometry. Identifications are made by the infrared KBr technique on a portion of the column eluates. A collaborative study of the method was conducted. Average recoveries of 99.45% for acetaminophen and 100.9% for salicylamide were obtained for a synthetic standard mixture. The study also included 3 commercial drug products which were assayed for acetaminophen and salicylamide.
Diazomethane Methylation of a Mixture of Chlorophenoxy Acids and Dinitrophenols
Authors: Howard Samuel F , Yip George 
Published: February 2020

Abstract
Three different methylation procedures using diazomethane were evaluated on 2,4-D, 2,4,5-T, 2,4,5-TP, 2,4-DB, 2,3,6-TBA, DNOC, DNBP, and DNOCHP: (I) diazomethane alone, (II) diazomethane and methanol, (III) diazomethane, methanol, and HC1. Evaluations were made by comparing electron capture GLC peak heights or peak areas of reacted products with those of standards. Volatility losses were observed with method I. Completeness of dinitrophenol methylation varied with the lot of methanol used with methods II and III. From the results of this study, method I was modified by the addition of isooctane to the reaction vessel to prevent the sample from evaporating to dryness and the use of a 70°C water bath to speed up the reaction. Conversion of all pesticides by the modified procedure was over 90%.
Water in Granular Triple Superphosphate
Authors: Duncan R D 
Published: February 2020

Abstract
The gain or loss of moisture by samples of granular triple superphosphate during grinding in preparation for analysis depends upon both the conditions of manufacture of the material and the humidity of the atmosphere in the grinding room. Care should be exercised in the preparation of superphosphate samples for analysis, and the relative humidity in the grinding room probably should be ≤40%.
Comparison of Four Extraction Procedures for Root-Translocated Dieldrin in Maize, Kale, Alfalfa, and Wheat
Authors: Caro Joseph H 
Published: February 2020

Abstract
Internal dieldrin residues in 5 crops were determined by gas chromatography after extraction by 4 different methods. Blending with hexane-isopropanol (2 + 1) followed by Soxhlet treatment with chloroform-methanol (1 + 1) generally extracted the most pesticide. Blending with acetonitrile-water (65 + 35) was a less tedious, satisfactory substitute procedure. Blending with acetonitrile or with hexane-isopropanol alone gave lower recovery of dieldrin. Recovery with either of these 2 solvents was especially low in crops of low moisture content.
Hybrid Assay for Trisulfapyrimidine Preparations
Authors: Banes Daniel , Riggleman Oscar H 
Published: February 2020

Abstract
A method is described for the assay of trisulfapyrimidines tablets and trisulfapyrimidines oral suspension. Total sulfonamides are measured colorimetrically by the Bratton-Marshall procedure, and sulfadiazine is quantitated directly by means of its specific reaction with thiobarbituric acid. Sulfamethazine is separated from its homologs by column partition chromatography and is determined by ultraviolet spectrophotometry. When applied to commercial samples of trisulfapyrimidines tablets and oral suspensions, this hybrid method yields data that are consistent with assays of the same samples by the official nitrite titration method.
Characterization of Some Lincomycin and Cyclamate Salts by Thermal Analysis and Infrared Spectroscopy
Authors: Neville G A , Ethier J C , Bright N F H , Lake R H 
Published: February 2020

Abstract
The relative thermal stability of lincomycin. HCl.H2O, lincomycin cyclamate, calcium cyclamate.2H2O, and sodium cyclamate was studied by differential thermal analysis and by thermogravimetric analysis. Lincomycin. HCl.H2O easily undergoes thermal degradation with the release of methyl mercaptan, but the cyclamate anion confers considerably greater thermal stability on the lincomycin moiety. Calcium cyclamate.2H2O was found to undergo a 2-step thermal dehydration analogous to that undergone by CaSO4.2H2O, including termination in the formation of CaSO4· Grating infrared spectra are reproduced for lincomycin.HCl.H2O, cyclohexylsulfamic acid (cyclamic acid), sodium cyclamate, and calcium cyclamate.2H20. Principal group frequencies are assigned with the aid of deuterium exchange studies and thermal dehydration limits. Infrared characteristics of derivatives of sulfamic acid are described for the first time and evidence is presented for the trans amide configuration in lincomycin. HCl.H2O.
Semiautomated Determination of Sulfadimethoxine in Feeds
Authors: Araujo M , De Ritter E , Osadca M 
Published: February 2020

Abstract
A method is described for determining sulfadimethoxine in feeds at levels of 0.00625 to 0.0125%. Colorimetry based on the Bratton-Marshall reaction is carried out by an automated procedure, using extracts prepared by manual digestion, extraction, and filtration. Of several extraction procedures tried, only alcohol extraction after digestion with ficin yielded both 100% recoveries of sulfadimethoxine and negligible readings on unmedicated feeds. After preparation of the extracts, 20 samples/hr can be assayed by the automated colorimetric method. Increased precision is achieved by automation of the colorimetry.
Determination of 1,4-Dihydroxyanthraquinone in D&C Green No. 5 and the Former External D&C Violet No. 2
Authors: Hoskins Elizabeth C 
Published: February 2020

Abstract
The certifiable color D&C Green No. 5 and the formerly certifiable color External D&C Violet No. 2 may contain small quantities of the intermediate quinizarin, 1,4-dihydroxy-anthraquinone. The quinizarin is separated from the color by solvent extraction and is determined spectrophotometrically. Recoveries averaged 92 and 99% for D&C Green No. 5 and former External D&C Violet No. 2, respectively.
Colorimetric Method for the Determination of Vitamin D in Fortified Whole and Partially Skim Fluid Milks
Authors: Panalaks T 
Published: February 2020

Abstract
Vitamin D in fortified milk was determined from a standard curve prepared from the addition of known amounts of the vitamin to unfortified milk. The usual exhaustive extractions for isolation of the unsaponifiable fraction were replaced by a labor-saving benzene partition technique. The main interfering substance, cholesterol, was removed by passing the sample extract through a column of Celite impregnated with digitonin. Other interfering substances were removed by partition and adsorption column chromatography. Oxidative deterioration of the vitamin during saponification and subsequent analytical steps was prevented by additions of antioxidants and by addition of a high boiling hydrocarbon to prevent drying. The vitamin concentration was determined colorimetrically at 500 nm after reaction with antimony trichloride, using a correction factor derived from absorbances measured at 435 and 550 nm. The use of a color inhibitor was eliminated. The method when applied to whole and partially skim milks fortified with vitamin D in the range from 22 to 44 IU/100 ml milk gave recoveries of 92 and 103%, respectively.
Effect of Cooking Utensil Composition and Contents on the Reductive Dechlorination of DDT to DDD
Authors: Deloach Hiroko K , Hemphill Delbert D 
Published: February 2020

Abstract
The reductive dechlorination of DDT to DDD by some cooking utensil compositions and contents is demonstrated and the identification of specific reducing agents of DDT is investigated. Iron is found to be the most active reducing agent of DDT. A progressive loss of DDT and accumulation of DDD from DDT are observed when DDT standard is boiled with double-distilled water in metal utensils (iron, stainless steel, or aluminum) or in glass utensils containing iron powder. Non-metal utensils (Teflon, glass, or enamel) by themselves do not give an accumulation of DDD from DDT despite considerable loss of DDT. Teflon-coated utensils are ineffective in the reduction of DDT and tend to adsorb pesticides on their surface. A substance (or substances) which is present in vegetables also acts as a DDT-reducing agent as shown by boiling DDT with vegetables in glass utensils.
Colorimetric Determination of Aniline Derivatives in Natural Waters
Authors: El-Dib M A 
Published: February 2020

Abstract
A rapid, direct, and sensitive colorimetric method has been proposed for the determination of aniline derivatives in surface waters. The method is based on diazotization of the primary aromatic amine and coupling with resorcinol or 1-naphthol. Hydroxy-azo dyes obtained have considerably high absorptivities, rendering the method sensitive enough to determine anilines at 0.1 ppm. The effects of pH, saline constituents of waters, coupling phenols, and substituents on color intensity are discussed. Coefficients of variation ranged between 6 and 0.5, according to the nature of aniline derivative and the amount determined. Precision of the method is greatly increased when the amount of the existent aniline ranges between 40 and 100 μg.
Comparison of the Official AOAC Method with Rapid Methods for the Analysis of Moisture in Meats
Authors: Cohen Edward H 
Published: February 2020

Abstract
Moisture studies were conducted on 4 types of meat. A method specifying 2 hr at 125-150°C in a gravity convection oven gave similar results to 24.003. Five rapid methods were also evaluated: the IR automatic moisture analyzer, the IR moisture determination balance, toluene extraction, specific gravity change, and hot plate methods. The methods were evaluated for precision and recovery of moisture as compared with the official AOAC method and for their practicability, ease of handling, and rapidity of analysis.