bluuebunny/crossref_metadata_2025_split huggingface dataset:
Collaborative Study of a Column Chromatographic Method for Chlorothiazide, Methyclothiazide, and Polythiazide
Authors: Fazzari F Raymond 
Published: February 2020

Abstract
Chlorothiazide is eluted from a K2HPO4 column with acetic acid-ether solvent and extracted from the organic phase into HCl for the Spectrophotometric determination. Methyclothiazide and polythiazide are eluted from a NaHCO3 column with CHCl3 and measured directly. The method was collaboratively studied by 10 analysts. The average per cent recovered and standard deviations for preparations of chlorothiazide and methyclothiazide were 100.2±0.67 and 99.8±1.64, respectively. The method for chlorothiazide and methyclothiazide has been adopted as official first action.
Separation and Determination of FD&C Red No. 4 and FD&C Red No. 40 in Maraschino Cherries by Column Chromatography
Authors: Draper Ronald E 
Published: February 2020

Abstract
FD&C Red No. 4 and FD&C Red No. 40 are extracted from a sample-Celite mixture in a chromatographic column by elution with a 5% solution of Amberlite LA-2 liquid anion exchange resin in n-butanol. The colors are extracted from the resin with dilute ammonia and then extracted into n-butanol. After evaporation to dryness, the colors are separated by Celite chromatography, using pH 1.5 HCl buffer as immobile phase. Red No. 4 is eluted with n-butanol-CCl4 (1+1) and Red No. 40 is eluted with a 5% solution of Amberlite LA-2 resin in hexane. The compounds are measured spectrophotometrically. Results on a commercial sample (5 trials) ranged from 74 to 76 ppm Red No. 4 and 72 to 81 ppm Red No. 40. Spike recoveries at various levels averaged 98% for FD&C Red No. 4 and 95% for FD&C Red No. 40.
An Isolation and Cleanup Procedure for Low Levels of Organochlorine Pesticide Residues in Fats and Oils
Authors: Porter Mildred L , Burke Jerry A 
Published: February 2020

Abstract
An isolation and cleanup is described for low levels of organochlorine residues (about 0.005 ppm) in fats and oils, prior to electron capture gas-liquid chromatography. The fat or oil is distributed on a column of unactivated Florisil and the residues are partitioned into an eluant of 10% water in acetonitrile. Florisil column chromatography with an elution solvent system comprised of mixtures of methylene choride, acetonitrile, and hexane is used for the final cleanup. Extracts prepared in this manner are sufficiently free of fatty extractives to permit injection of the equivalent of 50–60 mg fat sample for GLC. The procedure should be especially useful in determination of low levels of organochlorine pesticide residues in the fat of certain dietary composites.
Qualitative Identification of Furazolidone, Tylosin, and Zoalene in Feeds
Authors: Barefield Lewis A 
Published: February 2020

Abstract
Rapid microscopic methods are described for the identification of furazolidone, tylosin, and zoalene in mixed feeds at levels normally used for feeding. The drugs are identified by the colors produced in solution : furazolidone-intense blue in dimethylformamide and potassium hydroxide, zoalene—bright green in dimethylformamide and potassium hydroxide, and tylosin—pink-orchid in distilled water. Collaborative results showed excellent agreement, and the methods have been adopted as official first action.
Collaborative Study of a Qualitative Screening Test for the Detection of Cyanide in Wines and Spirits
Authors: Bates Brian L 
Published: February 2020

Abstract
Six laboratories collaboratively studied the method reported earlier for the qualitative detection of cyanide in wines and spirits at and below 0.1 ppm. Five samples of rectified spirit, labeled A, B, C, D, and E, and 5 samples of wine, labeled U, V, X, Y, and Z, were sent to each collaborator. Four of the 5 samples of both products were spiked with cyanide, in the form of K4FeCN6.3H2O, below 0.1 ppm. One sample in each set was free from cyanide and served as a blind blank. In the first study a total of 60 determinations were performed by the collaborators, plus the associated blank and standard determinations. Twenty validation determinations on 2 separate sets of both series of test samples were also performed in the Associate Referee’s laboratory prior to distribution of the samples. Because the results obtained from the overseas collaborators in the first study were not satisfactory and indicated that decomposition of the added potassium ferrocyanide had occurred during the unavoidably long period of transport and storage, all collaborators were asked to repeat the exercise on samples freshly spiked in their own laboratories and to report the results. The results obtained by the 3 collaborators in the second study were quite satisfactory and compared favorably with the results obtained by local collaborators in the first study. The method has been adopted as official first action.
Rabbit Eye Irritation Test: Collaborative Study
Authors: Marzulli Francis N , Ruggles Dennis I 
Published: February 2020

Abstract
The well known Draize rabbit eye irritation test was evaluated. Ten laboratories (3 government, 3 industrial, and 4 commercial) participated and 7 liquid materials were tested. Tests were conducted 2 at a time, using 1 of 6 different materials with the same control substance (70% isopropyl alcohol), for a total of 12 tests. Test materials were selected with stringency, by employing compounds which were difficult to evaluate as they were neither strongly irritant nor innocuous. By the Draize procedure, 5 of these materials were considered irritants, and 2 nonirritants. Results showed that if all 4 criteria for eye irritation (changes in cornea and iris and conjuctival redness and chemosis) were employed, collaborators were quite consistent in separating an irritant from a nonirritant substance. The method has been adopted as official first action.
Asbestos Fibers in Beverages, Drinking Water, and Tissues: Their Passage Through the Intestinal Wall and Movement Through the Body
Authors: Cunningham Hugh M , Pontefract Roderic D 
Published: February 2020

Abstract
Methods were developed using an electron microscope to isolate and count asbestos fibers in liquids and tissues. Fibers were detected in beer, sherry, port, vermouth, soft drinks, and city drinking water at levels generally ranging from 1 to 11 million per liter. River water was higher in asbestos fibers than water passed through a city filtration system, and melted snow was considerably higher than river water. Asbestos fibers were also detected in parenteral solutions. Distribution studies on asbestos fibers administered to rats were performed with the electron microscope and were supplemented with studies using both tritiated and neutron-activated asbestos. Crysotile fibers were injected into the stomachs of rats and 2–4 days later fibers were isolated from the blood, spleen, liver, kidney, omentum, muscle, lung, and brain. Highest levels of orally administered fibers were found in the omentum; intravenously injected fibers resulted in highest levels in the liver and the lung.
Simplified Spectrophotometric Analysis of Plants for Selenium
Authors: Olson Oscar E 
Published: February 2020

Abstract
A simplified Spectrophotometric method is described, which is based on the light absorption at 378 nm of the piazselenol formed by the reaction of 2,3-diaminonaphthalene with selenite. Reproducibility and recovery studies and comparison of the results with those obtained by fluorometric analysis, 3.074–3.078, suggest that the Spectrophotometric method is suitable for plant samples containing &gt;2 ppm of the element. It can also be used in the measurement of selenium added to feed premixes or in the diagnosis of selenium poisoning in cattle by hair analysis.
Collaborative Study of a Microbiological Method for the Assay of Neomycin Sulfate in Feeds
Authors: Williams Billy Joe 
Published: February 2020

Abstract
The official method for the microbiological assay of neomycin sulfate in feeds was modified by adding pH 8.0 Tris buffer to and deleting CaC12 from the base and seed agars. The modified method was collaboratively studied by 13 laboratories. Each laboratory performed single assays of 4 feed types at 4 medication levels over 4 months. The average recovery for all collaborators was 115.6% of theory with a coefficient of variation of 20.4%. Neither order of assay, feed type, nor ratio of neomycin B to C in the premix significantly affected the assays. Inhibition zone diameters were significantly larger for standard solutions prepared in 1 + 24 dilutions of inactivated feed extracts than for identical concentrations of standard in 1+49 dilutions of identical feed extracts. This study has been discontinued and a search for a more reliable method has been initiated.
Determination of Chlorinated Pesticides in Whole Blood
Authors: Stretz Paula E , Stahr Henry M 
Published: February 2020

Abstract
Eight whole blood samples spiked with lindane, dieldrin, and p,p′-DDT at levels of 2.5, 12.6, 126, and 630 ppb each were sent to 11 collaborators for analysis. The method evaluated uses sulfuric acid to liberate the pesticides from the blood matrix. The pesticides are then extracted with 10% acetone in hexane. Pesticides were identified and quantitatively analyzed by gas-liquid chromatography, using an electron capture detector. Mean values at all levels are in good agreement with the spiking levels. However, statistical analysis of the data reveals a large systematic error. Further evaluation of the sulfuric acid method by comparison with other methods is recommended.
Examination of Automobile Paints by Laser Beam Emission Spectroscopy
Authors: Manura John J , Saferstein Richard 
Published: February 2020

Abstract
An analysis was performed on 112 paint chips of various colors from wrecked, late model automobiles. A laser beam microprobe was used in conjunction with an emission spectrograph in order to determine the applicability of the laser microprobe in forensic paint analysis and the specificity of the emission spectrograph in paint analysis. The emission spectrograph was employed to determine the relative abundances of elements in the surface layers of the paint chips. The laser microprobe attachment permitted the analysis of very small paint chips and the analysis of the surface layers of the multilayer paint chips. The results indicated that of the 112 paints analyzed (a) 11 pairs of paints which were physically identical could be distinguished by the emission spectrograph, (b) 4 pairs of paints which were physically identical were also identical by the emission spectrograph, and (c) 3 pairs of paints which were not physically identical were identical by the emission spectrograph. From the results it was concluded that, although the elemental composition cannot individualize a paint chip, it is a useful forensic technique when supplemented with a microscopic examination.
Analysis of Organic Acids in Fruit Products by Anion Exchange Isolation and Gas Chromatographic Determination
Authors: Baker David W 
Published: February 2020

Abstract
The method described involves passing an alcoholic extract of fruit product through a cation exchange resin column and then through an anion exchange resin column. Neutral fruit components are washed from the columns with alcohol and acetone solutions. Acidic components trapped on the anion column are eluted using 6N formic acid in acetone. An aliquot of the eluate is evaporated to dryness after the addition of benzene to remove the excess formic acid as an azeotrope. The residue is allowed to react with bis(trimethylsilyl)acetamide or bis(trimethylsilyl)trifluoroacetamide to form trimethylsilyl ether-ester derivatives which are detected by gas chromatography on a nonpolar (OV-1) column. Good recoveries were obtained for some common organic acids (succinic, fumarie, malic, tartaric, trans- aconitic, and citric acids) from fruit juice.
Quantitative Determination of Sorbitol in Raisins and Dietetic Foods by Gas-Liquid Partition Chromatography
Authors: Fernandez-Flores Enrique , Blomquist Victor H 
Published: February 2020

Abstract
A rapid method for the determination of sorbitol in raisins and dietetic foods is described. Sorbitol is converted to a trimethylsilyl derivative after precipitation of interfering organic acids as lead salts and determined by GLC, using α-d-glucoheptose as an internal standard. Nine samples of dietetic foods were analyzed. The results compared satisfactorily with the declared sorbitol content for each product. The recovery of 0.5% sorbitol added to raisins was 93%.
Criteria for Mycotoxin Standards
Authors: Rodricks Joseph V 
Published: February 2020

Abstract
It is recommended that all samples of mycotoxins to be used as analytical standards be in compliance with certain criteria of purity and that methods be made available for analysts to check the concentration and purity of their standards. General criteria for meeting these goals are described. A procedure for the determination of the concentration and purity of aflatoxin M1 standards, which was used in an IUPAC collaborative study to determine the stability of M1, is recommended for acceptance by the AOAC.
Chemical Confirmation of BHC Isomers : Comparison of Alkaline Reactions in Solution and by Gas Chromatographic Pre-Column
Authors: Cochrane William P , Maybury Ronald B 
Published: February 2020

Abstract
A rapid procedure that involves treatment with sodium methoxide (NaOMe) solution is described for the qualitative confirmation of lindane (and other BHC isomers) residues in cereal, animal feed, meat, and fat samples. Losses encountered in the evaporation and partition steps are discussed. Optimum GLC conditions, both programmed and isothermal, for the separation of the 1,3,5-, 1,2,4-, and 1,2,3-trichlorobenzene products are given. Comparison of the NaOMe solution reaction with an alkaline pre-column technique revealed that the latter saved time in the analysis of cereal, animal feed, and cheese extracts. The alkaline pre-column method did not eliminate interferences in some meat and fat samples; the NaOMe solution reaction does eliminate these interferences. A lower level of 0.01 ppm lindane in a 10 g sample can be confirmed by the procedures described.
Neutron Activation Analysis for the Detection of Firearm Discharge Residues Collected on Cotton Swabs
Authors: Michael Hoffman C 
Published: February 2020

Abstract
Cotton swabs moistened with 5% HNO3 are frequently used by police investigators to process a suspect’s hands for the presence of gunshot residue. A neutron activation analysis procedure is described for testing these swabs for barium and antimony, which are commonly found in firearm residues. The limitations of the method are also discussed.
Determination of Chlorinated Insecticides in Suspended Sediment and Bottom Material
Authors: Goerlitz Donald F , Law Leroy M 
Published: February 2020

Abstract
Chlorinated hydrocarbon insecticides in suspended sediment and bottom material are extracted with acetone-hexane solvent, with the extractants added separately. Co-extractives, including polychlorinated biphenyls and polychlorinated naphthalenes, are isolated by adsorption chromatography. Sulfur is removed by precipitation. Mean recoveries from 8 spiked samples ranged from 75 to 99% for 9 chlorinated hydrocarbon insecticides. An average recovery of 97.9% was obtained for bottom material samples contaminated with chlorinated hydrocarbons. Recoveries were compared with those obtained by exhaustive extraction of the contaminated samples.
Atomic Absorption Spectrometric Determination of Arsenic
Authors: Hoover William L , Melton James R , Howard Peggy A , Bassett James W 
Published: February 2020

Abstract
The official AOAC method for arsenic in feeds has been adapted to an atomic absorption spectrophotometric technique in which the arsenic trapped in the absorbing solution is aspirated into the flame. Values as low as 0.5 μg As/g can be measured in a 10 g sample. A modified digestion procedure is described. A second method is described for the determination of submicrogram quantities of arsenic whereby the arsine gas is generated into a plastic bag and introduced directly into the flame. Air-acetylene fuels are utilized, requiring no alterations in the nebulizer and mixing chamber. Sensitivity attained from a 10 g sample is 0.1 μg As/g. Results of various biological matrices, which were determined by the AOAC method and the 2 described methods, compare favorably.
Thin Layer Chromatographic Quantitative Analysis of Polythiazide Tablets
Authors: Flinn Paul E , Smith Thomas G 
Published: February 2020

Abstract
A thin layer chromatographic method, using methylene chloride-methanol (90+2) as a developing system, for the quantitative analysis of polythiazide is described in which the polythiazide is concentrated over a visible area of less than 2 sq mm adsorbent (SilicAR 7GF) on a glass plate or fiber glass sheet (SAF type) for ease of elution. Data from 5 determinations showed a coefficient of variation of 0.63% with a range of ±0.75% at the 100 μg spotting level.
Automatic Potentiometric Titration of Sodium Chloride in Certifiable Water-Soluble Colors
Authors: Graichen Charles , Bailey John E 
Published: February 2020

Abstract
A Fisher Titralyzer® is used for a rapid automatic potentiometric determination of sodium chloride in certifiable colors. The sulfonated colors are dissolved in water and the solution is titrated. The water-soluble fluorescein colors are first precipitated with acid, and an aliquot of the filtrate is titrated. The method is applicable to all certifiable water-soluble colors except D&C Red No. 19.
Rapid Procedure for Determination of Formaldehyde in Maple Sirup
Authors: Karasz Albert B , DeCocco Frank , Maxstadt John J , Curthoys Allan 
Published: February 2020

Abstract
A modification of the official AOAC method, 31.184—31.186, has been developed which requires no distillation. The acetylacetone reagent is added directly to a diluted sirup sample. The color formed is extracted with isobutanol and the absorption of the extract is measured at 415 nm against a blank extract processed without acetylacetone. Standard curves are prepared, as in the official method, with spiked sirups. The proposed method measures 42.3% of the formaldehyde present; the official method measures 27.1%. Results obtained using the modification compare well with those obtained by the official method and show equivalent precision. A determination can be completed in 1 hr and a large number of samples can be processed simultaneously.
Direct Chromatography of Some N-Methylcarbamate Pesticides
Authors: Lorah Esther J , Hemphill Delbert D 
Published: February 2020

Abstract
Carbaryl (1-naphthyl methylcarbamate), Mesurol® (4-methylthio-3,5-xylyl methylcarbamate), promecarb (m-cym-5-yl methylcarbamate) , Zectran® (4-dimethylamino-3,5-xylyl methylcarbamate), and 4-dimethylamino-3,5- xylenol were successfully chromatographed on Chromosorb W support, surface-modified with Carbowax 20M. The intact compounds were detected by means of the nitrogen or sulfur response of an alkali flame detector. Calibration curves were linear over the range 4 to 2000 ng. Average pesticide recoveries of 90—100% were obtained from fortified vegetable samples.
Determination of Tough Strings and Fibrous Material in Frozen Green Beans
Authors: Varseveld George W 
Published: February 2020

Abstract
Two methods were collaboratively studied: a method for the determination of tough strings in frozen green beans, adapted from the Food and Drug Administration method for canned green beans, and a method for the determination of fibrous material. Results from 5 collaborators for the tough strings method indicate substantial intralaboratory error. Coefficients of variation were between 20.0 and 25.6% for 3 samples containing 10 to 22% tough string units. Inherently high sample variation is a problem. It is recommended that the tough strings method be given further study. Six collaborators assayed fiber in 4 pairs of frozen green bean samples. Statistical results revealed standard deviation values ranging from 0.010 for a sample averaging 0.14% fiber to 0.025 for a sample averaging 0.33% fiber. The proposed method has been adopted as official first action.
Collaborative Study of Ion-Pairing Column Chromatographic Determination of Neostigmine Bromide
Authors: Kling Rita E 
Published: February 2020

Abstract
A revised version of the ion-pairing column chromatographic method for neostigmine bromide in tablets and ophthalmic solutions was subjected to a collaborative study. Eleven collaborators assayed a commercial tablet preparation, a simulated tablet formulation, 5 individual tablets, and a simulated ophthalmic formulation. The relative standard deviations were 2.2, 1.8, and 1.5% for the 2 tablet samples and the ophthalmic solution, respectively, and 2.4% for the individual analysis. The method has been adopted as official first action.
Determination of Soy Products in Meat-Soy Blends
Authors: Formo Marvin W , Honold Guy R , Maclean David B 
Published: February 2020

Abstract
The concentrations of various elements and fiber in ground beef and textured soy flour were measured, respectively, by atomic absorption spectrophotometry and a modified AOAC fiber method. The average concentration, standard deviation, and coefficient of variation for magnesium, manganese, and fiber, respectively, in textured soy flour are 2948 mg/kg, 186 mg/kg, 6.3% ; 33.4 mg/kg, 3.4 mg/kg, 10.1% ; 2.03%, 0.27%, 13.3%. The average concentration, standard deviation, and coefficient of variation for magnesium, manganese, and fiber, respectively, in regular ground beef are 151 mg/kg, 7.4 mg/kg, 4.9% ; 0.125 mg/kg, 0.025 mg/kg, 20%; 0.01%. From computer analysis of the data from an interlaboratory study of the analysis of textured soy flour–ground beef mixtures, the expected total errors (one standard deviation in absolute percentages) of the method applied to a product containing 20% textured soy flour hvdrated 1+2 were as follows for the respective indices used: magnesium 1.8%, manganese 2.7%, and fiber 8.8%. Analysis of ground beef and textured soy flour for ash, hemicellulose, stachyose, phosphorus, potassium, copper, and zinc revealed that these constituents were not suitable indices of textured soy flour content in textured soy flour-ground beef mixtures.
Evaluating the Potential for Occurrence of Aflatoxins in Black Sunflower Seeds
Authors: Llewellyn Gerald C , Eadie Thomas 
Published: February 2020

Abstract
A modified cotttonseed extraction and purification procedure was used to detect aflatoxins in samples of sunflower seeds. No aflatoxins (&lt; 2 ppb) were detected in over 50 random samples taken from varied lots of commercial seeds on sale in central Virginia. No Aspergillus flavus-like or A. parasiticus-like organisms were seen in cultures of the natural flora of such seeds when grown on both whole and crushed seeds. No naturally occurring aflatoxins (&lt; 2 ppb) were detected in the cultures. Standing cultures of crushed seeds, when inoculated with A. flavus ATCC 15548, resulted in 271 μg total aflatoxin/g medium within a 2 week period of growth at room temperature. The crushed seed cultures had the following ratios for B1, B2, G1, and G2: 12, 1, 17, and 3, respectively. Whole seed cultures tested about 25% lower than crushed cultures for total aflatoxin content but whole cultures did lack detectable levels of B2. The whole seed cultures had the following ratios for B1, B2, G1? and G2: 13, 0, 19, and 2. The increase in toxin levels in the crushed cultures for each type of toxin compared to the total increase was as follows: G1 increased 37%, B1 increased 29%, G2 increased 21%, and B2 accounted for 12% of the total increase. Black sunflower seeds, whole or crushed, will support the growth of A. flavus and the production of aflatoxins at levels that may approach that of rice medium but not that of coconut medium.