bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inhalation Toxicology
Authors: Macfarland Harold N 
Published: February 2020

Abstract
Two kinds of problems associated with developing standardized procedures for the safety evaluation of new compounds are identified. The first of these is the question of the desirability of using such standard methods. It is concluded that a basic set of procedures is to be recommended, but this should be supplemented with special tests as may be indicated. The second problem is connected with the technical difficulties of any given type of assay and is normally dealt with in terms of the state of the art at the time. Assays by the inhalation route tend to be custom designed and do not follow standard protocols. One of the causes of this situation is the propensity of individual investigators to design de novo the equipment used to effect exposure of animals to airborne substances. Second, some confusion exists because investigators do not always appreciate that the concentration-time product is not the same as the true dose received by the exposed subjects and this may lead to anomalies when dose-response relationships are being characterized. It is suggested that interlaboratory studies be undertaken to ascertain the variability that might be expected in independent assays of inhalation toxicity.
Comparison of Two Formulations of Acid Orange 12 for the Determination of Protein in Milk
Authors: Sherbon John W , Fleming Richard 
Published: February 2020

Abstract
A new formulation of Acid Orange 12 reagent solution for the determination of protein, using 16.037–16.041, has been tested for linearity of response and dye binding capacity. A total of 13 fluid dairy products and one nonfat dry milk were collaboratively studied by 5 laboratories, each using both the old and the new dye solutions. Separate calibration curves were prepared for each dye solution. Analysis of variance (mixed model) showed that the dye solution and the dye solution × sample interaction were nonsignificant sources of variation. Laboratories were a significant source; the estimated standard deviation due to laboratories was 0.023% protein. It appears that very slight differences in calibration curves exist in the different laboratories, but it is not known whether this is associated with the old or new solutions. The new formulation has been adopted as official first action for use in method 16.037–16.041.
Electrophoretic Method for Studying Proteins in Beer
Authors: Gorinstein Shela 
Published: February 2020

Abstract
The proteins in beer were concentrated by the tannin-caffeine method, followed by electrophoresis on agar gel to separate 7 protein fractions: albumin, glutelin-1, gIutelin-2, β-globulin, and α-, β, and γ-hordein. Emission spectroscopy and spectrophotometry of electrophoretically separated proteins revealed ferro- and cuprometal-protein complexes. Analysis of the data shows that beer clarification decreases the content of the trace elements (iron, copper, calcium, and oxalate ion) and that of total protein and protein fractions (albumin, β-globulin and α-, β; and γ-hordein).
Automated High-Pressure Liquid Chromatographic Assay of Robenidine Hydrochloride
Authors: Zagar John B , Ascione Peter P , Chrekian George P 
Published: February 2020

Abstract
High-pressure liquid chromatography has been applied to the separation and analysis of robenidine hydrochloride in the presence of its chemical precursors. It provides a rapid and specific method for the analysis of robenidine in technical material as well as feed premixes and is capable of distinguishing the intact drug from its degradation products. The chromatographic system employs a mixture of methanol, acetic acid, and methylene chloride as the mobile phase and a controlled pore glass as the stationary phase. Sample manipulation has been automated in 2 ways. In the first, manually prepared samples are automatically injected onto the column for separation and quantitation. In the second, a totally automated sample handling system, weighed samples are extracted, diluted, filtered, and then injected onto the column, all in a sequential manner. These procedures are capable of giving quantitative results at a rate of 10 samples/hr with a relative standard deviation of 1.13%.
Gas-Liquid Chromatographic Determination of IV-Octylbicycloheptene Dicarboximide
Authors: Meinen Vernon J 
Published: February 2020

Abstract
A gas-liquid chromatographic (GLC) method is described for the quantitative determination of /V-octylbicycloheptene dicarboximide (MGK 264 synergist) in technical materials and in various formulations. The samples are diluted with acetone and analyzed by GLC, using a flame ionization detector and a column packed with OV-1 on Chromosorb W (HP). Preliminary work indicates that satisfactory results can be obtained with the technical material and several different formulations.
Electron Capture Gas-Liquid Chromatographic Method for the Simultaneous Analysis of 2,4-D, Dicamba, and Mecoprop Residues in Soil, Wheat, and Barley
Authors: Khan Shahamat U 
Published: February 2020

Abstract
A method has been developed for the simultaneous analysis of 2,4-D (2,4-dichIorophenoxyacetic acid), dicamba (2-methoxy-3,6-dichlorobenzoic acid), and mecoprop (MCPP; 2-[(4- chloro-o-tolyl) oxy] propionic acid) residues in soil, wheat, and barley. Soil and crop samples are extracted with acidic acetone and methanol, respectively. The extracts in diethyl ether are esterified with diazomethane and cleaned up by passing through a Florisil column. Extracts are analyzed by gas-liquid chromatography, using an electron capture detector to determine 2,4-D and dicamba residues. Mecoprop in the extract is not detected at low levels of concentration. However, bromination of the extract increases the response of the electron capture detector to mecoprop. The method is sensitive to about 0.05 ppm 2,4-D and dicamba and 0.5 ppm mecoprop. Recoveries of these 3 herbicides added to soil, wheat, and barley samples at 0.05, 0.1, 0.5, and 1.0 ppm levels were between 65 and 93% . The method was used for the simultaneous analysis of 2,4-D, dicamba, and mecoprop residues in wheat, barley, and soil samples obtained from fields sprayed with the herbicide formulation Kil-Mor.
Relative Retention Ratios of Ninety-Five Pesticides and Metabolites on Nine Gas-Liquid Chromatographic Columns Over a Temperature Range of 170 to 204ºC in Two Detection Modes
Authors: Thompson John F , Mann Jon B , Apodaca Alfred O , Kantor Edward J 
Published: February 2020

Abstract
Tables of relative retention data are presented for 95 organochlorine and organophosphorus pesticidal compounds at column oven temperatures from 170 to 204°C in 2° increments. Retention values, relative to aldrin or parathion (RRTA A or P) , were found to vary inversely with increasing column temperature for all compounds eluting later than the reference compound, and in direct proportion for those compounds eluting earlier than the fixed reference compound. Studies revealed a linear relationship between column temperature and relative retention ratios; thus, by obtaining precise values by gas-liquid chromatography for a number of pesticidal compounds at 170, 185, and 200°C, a computer program was developed to obtain RRTA A or P values at all 2° increments from 170 to 204CC, the customary limits in the gas-liquid chromatography of pesticides. The tables are valuable in the tentative identification of pesticidal peaks resulting from the chromatography of sample extracts for multiresidue assessment.
Evaluation of Methods for the Determination of Polymers and Oxidation Products of Heated Vegetable Oils: Collaborative Study of the Gas-Liquid Chromatographic Method for Non-Elution Materials
Authors: Waltking Arthur E 
Published: February 2020

Abstract
A method for measuring non-elution materials from a gas chromatographic column has been collaboratively studied. The average standard deviation is 1.8%. It is the first of 2 companion methods which are expected ultimately to provide a means of measuring the polymers and oxidation products of edible fats and oils. Data from some preliminary studies, which have been confirmed by the collaborative study, indicated that only those oils heated in an unnatural manner contained elevated levels of polymers. The collaborated method may be used as a rapid means for screening samples for further study when it is understood that any measurement obtained is a product of the polymers, oxidation products, and unsaponifiable matter of the sample.
Trimming as a Means of Removing Patulin from Fungus-Rotted Apples
Authors: Lovett Joseph , Thompson Ruben G , Boutin Brenda K 
Published: February 2020

Abstract
Penicillium expansum 1071,1172, NRLL 973, and Penicillium patulum ATCC 24550 were inoculated into Red Delicious, Golden Delicious, and Mcintosh apples. The decayed tissue was trimmed from the sound tissue, each fraction was weighed, and the patulin concentration in the juice was assayed by thin layer chromatography. The quantity of patulin in the whole apples and in decayed tissues was calculated and these values were used to determine the percentage of total patulin removed by trimming. The patulin content ranged from 140 to 4880 μg/apple. Trimming removed 93–99% of the total patulin, regardless of incubation temperature, fungus strain, or apple variety. Trimming of defective tissue from fungus-rotted apples could substantially reduce the patulin concentration.
Collaborative Study of Techniques for the Extraction of Iron and Zinc from Fertilizers
Authors: Wherley Sandra K , Jones Clyde E 
Published: February 2020

Abstract
Water, chelate, and acid techniques were compared for the extraction of iron and zinc from fertilizer samples. The water and chelate extractions were studied to offer an alternative to the official final action acid extraction, 2.098(a)–(c); atomic absorption spectrophotometry was the determinative step. The results for 10 samples from 24 laboratories were examined statistically and were sufficiently reproducible for widespread use of the methods. Statistical treatment of the data from the proposed methods compared favorably with that from the official method. Both the water and chelate extraction techniques have been adopted as official first action, supplementary to 2.098.
Collaborative Study of a Microbiological Assay for Lasalocid Sodium in Feeds
Authors: Scheiner Jacob 
Published: February 2020

Abstract
The microbiological cylinder plate assay method for lasalocid sodium reported earlier was studied in a slightly modified form by 7 laboratories. Assay values paralleled recovery values and all data were corrected by the corresponding daily recovery factor for the feed type. Agreement between laboratories for mashes and pellets containing 0.0064, 0.0080, and 0.0096% lasalocid sodium was satisfactory. Coefficients of variation for mashes were 14.6, 9.8, and 10.7% and for pellets, 15.2, 10.9, and 15.6%. The average of the values found for the 3 mashes was 99.4% of the calculated value and for the 3 pellets, 86.5%. The method has been adopted as official first action.
Interference of 2,3,4,4,5,6-Hexachloro-2,5-cyclohexadien-l-one in the Gas-Liquid Chromatographic Analysis of Octachlorodibenzo-p-dioxin in Commercial Pentachlorophenol
Authors: Wilkinson John E 
Published: February 2020

Abstract
2,3,4,4,5,6-Hexachloro-2,5-cyclohexadien-lone (2,5-HCP), if present in commercial pentachlorophenol (PCP), will interfere with the gasliquid chromatographic analysis of octachlorodibenzo- p-dioxin (OCDD). Different columns (10% UCW-98 and 5% OV-1) and temperature programming were tried without success in separation. 2,5-HCP chromatographed alone at 250°C does break down into several components, one matching the retention time of PCP (0.92 min). The major component eluted within 0.06 min of OCDD.
Atomic Absorption Spectrophotometric Determination of Selenium in Animal Feed Premix, Using the Vapor Generation Technique
Authors: Ng Samuel , Mcsharry William 
Published: February 2020

Abstract
An atomic absorption spectrophotometric method, using the vapor generation technique for the determination of selenium in animal feed premixes containing 0.4–0.002% selenium, is described. After the sample was digested in perchloric acid and hydrogen peroxide and reduced with 6M HC1, 3 aliquots of sample, each containing about 0.4 μg Se, were taken for analysis by the standard addition method. Sodium borohydride pellets were used for the generation of selenium hydride. The relative standard deviation of a single determination averaged ±19%.
Collaborative Study of a Potentiometric Method for the Determination of Fluoride in Vegetation
Authors: Jacobson Jay S , Heller Laurence I 
Published: February 2020

Abstract
A collaborative test was performed to evaluate a new potentiometric method for the analysis of fluoride in vegetation. The study was designed to provide estimates of accuracy and within- and between-laboratory precision of a method that employs extraction of fluoride, followed by analysis with an ion selective electrode. A group of laboratories experienced in fluoride analysis was provided with representative aliquots of specially prepared samples of vegetation and a detailed set of instructions. Reference values were established for the fluoride concentrations of vegetation samples prior to their distribution. Nine of the 23 laboratories participating in the study adhered strictly to instructions so the results from these 9 participants were used to evaluate the method. The coefficient of correlation between results from selected laboratories and reference values was 0.999. Deviations from reference values averaged 5.4% and relative standard deviations ranged from about 20% at 24 ppm to about 10% for concentrations &gt;100 ppm fluoride. On the basis of these results, the new method has been adopted as official first action. The method is simpler and faster; it requires less equipment than the current official final action method (25.029–29.035) and can be used to estimate fluoride concentration in the foliage of plants exposed to fluorides in the atmosphere or in soils provided samples contain &gt;10 ppm fluoride. Separate studies indicate, however, that certain samples of vegetation may be refractory to analysis by this potentiometric method. The final action method should be retained until a practical method is developed that is satisfactory for all types of vegetation.
Spectrophotometric Assay of Salsolidine Hydrochloride
Authors: Karawya Mohamed S , Diab Aly M 
Published: February 2020

Abstract
The proposed method is based on the reaction of salsolidine HCl with carbon disulfide and ammoniacal copper sulfate. The resulting salsolidine-copper-dithiocarbamate complex is extracted with benzene and measured spectrophotometrically at 448 nm. The method is applicable for the detection of 40-500 μg salsolidine/5 ml.
Determination of Polybrominated Biphenyl Residues in Dry Animal Feeds
Authors: Fehringer Norbert V 
Published: February 2020

Abstract
A new procedure is described for the determination of polybrominated biphenyls (PBBs) in dry animal feeds and developmental results are discussed. Finely ground feed is packed into a chromatographic column containing Celite and then eluted with methylene chloride. The concentrated extract is cleaned up by elution with petroleum ether through Florisil before gas-liquid chromatographic quantitation. Chromatograms thus obtained were essentially free of the interfering peaks encountered when using AOAC methods for pesticide residues in dry products. Results of feed analyses by the proposed procedure averaged 30% higher than those obtained by AOAC procedures. Recoveries of PBBs from samples fortified at levels of 0.04 to 0.4 ppm ranged from 90 to 104%, with an average of 98%.
The Food and Drug Administration and the Vinyl Chloride Problem‒An Overview
Authors: Schaffner Robert M , Lombardo Pasquale 
Published: February 2020

Abstract
Recent evidence has shown that chronic exposure to vinyl chloride by inhalation may cause cancer in laboratory animals and in man. Its possible oral effects are currently being investigated. The history of the significant events leading to the investigation of this chemical is presented. The current and future activities of the Food and Drug Administration in this area are also described.
A Rapid Method for the Determination of Manganese Ethylenebisdithiocarbamate and its Residues on Grains
Authors: Rangaswamy Jois R , Vijayashankar Yadathore N 
Published: February 2020

Abstract
A method has been developed, based on the periodate oxidation of the manganese in the coordination product of zinc ion and manganese ethylene bisdithiocarbamate to permanganic acid, to determine DithaneM-45. The relationship between the intensity of color and the concentration of manganese obeys Beer’s law up to 100 μg at 540 nm. The method can be easily applied to the determination of the active ingredient in formulations and also for residue analysis. The method is sensitive to 0.6 μg and can be used to determine 6 /xg fungicide at the 20 g sample level.
Procedural Change in the Official Method for the Extraction of Light Filth from Cocoa, Chocolate, and Press Cake
Authors: Brickey Paris M , Gecan John S 
Published: February 2020

Abstract
The bleaching agent used for the extraction of light filth from cocoa, chocolate, and press cake has been changed from hydrogen peroxide to sodium hypochlorite. Although hydrogen peroxide has many advantages, it also bleaches light colored fragments of insect cuticles, thus making counting difficult. The change has been adopted as official and 44.006(d) will be revised.
Simple Method for Simultaneous Detection of Aflatoxin and Zearalenone in Corn
Authors: Seitz Larry M , Mohr Harold E 
Published: February 2020

Abstract
A method is described for the simultaneous detection of aflatoxin and zearalenone in corn at 5 and 200 ppb, respectively. No evaporation of solvent is required and the procedure is simple enough to be considered for use at marketing locations. The presence or absence of these mycotoxins can be determined in 10–20 min/sample. The procedure involves an initial blender extraction with methanol, partitioning of fat and pigments into 1,1,2-trichlorotrifluoroethane (Freon-113) from an aqueous ammonium sulfate layer, followed by extraction of aflatoxin from the aqueous layer with chlorobenzene. The chlorobenzene extract can be spotted directly onto a thin layer chromatographic plate which requires only 4 min development. Concentrations of aflatoxin and zearalenone can be estimated by visual comparison of sample spots with standards.
Screening Method for the Detection of Aflatoxin, Ochratoxin, Zearalenone, Penicillic Acid, and Citrinin
Authors: Wilson David M , Tabor William H , Trucksess Mary W 
Published: February 2020

Abstract
A modification of the official method for ochratoxins and a screening method for zearalenone, aflatoxin, and ochratoxin is described and expanded to include citrinin and penicillic acid. The method uses 0.5N phosphoric acid-chloroform (1+10) in the initial extraction; the extract is divided and eluted from 2 columns to provide a quantitative thin layer chromatographic (TLC) method for aflatoxin and ochratoxin in com and dried beans. Aflatoxin and zearalenone are eluted from one column and ochratoxin, penicillic acid, and citrinin from the other. Ochratoxin A recoveries are low (50%) in peanuts. Zearalenone, penicillic acid, and citrinin were qualitatively recovered from com and beans; zearalenone and penicillic acid were recovered from peanuts but citrinin was not. Several TLC solvents were used to separate interferences.
A Spectrophotometric Procedure, Using Carboxypeptidase A, for the Quantitative Measurement of Ochratoxin A
Authors: Hult Karl , Gatenbeck Sten 
Published: February 2020

Abstract
In the method described, ochratoxin A is cleaved into ochratoxin α (free isocoumarin chromophore) and phenylalanine, using carboxypeptidase. Detection is based on the difference in fluorescence excitation spectra of ochratoxin A (380 nm, maximum) and ochratoxin α (340 nm, maximum). The quantitation of ochratoxin A is based on the loss of fluorescence intensity at 380 nm. The method has been used for the quantitative determination of as little as 4 μg ochratoxin A/kg barley and barley meal but it could be extended to other products.
Analysis of Pesticide Residues by Chemical Derivatization. II. N-Methylcarbamates in Natural Water and Soils
Authors: Coburn John A , Ripley Brian D , Chau Alfred S Y 
Published: February 2020

Abstract
A method for the quantitative determination of several N-methylcarbamates in natural waters and the applicability of the derivative to soil samples using a previously published extraction procedure are described. After extraction of the carbamates from the substrate, the carbamates are hydrolyzed in a 10% methanol-potassium hydroxide solution to form the phenolic hydrolysis products, which are isolated and derivatized with pentafluorobenzyl (PFB) bromide to produce the PFB ether derivatives. The PFB derivatives are cleaned up and fractionated on a silica gel microcolumn and determined by electron capture gas-liquid chromatography (GLC). Eight organophosphate pesticides and 2 phthalate acid esters that hydrolyze to phenols or phthalic acid were evaluated as potential interferences and were found not to interfere with any of the carbamates tested. Quantitative determinations of 0.1 μg carbofuran and 3-ketocarbofuran and 0.5 μg carbaryl, metmercapturon, and Mobam in a 1 L water sample are possible. Propoxur was not determined at levels &lt;1 μg/L due to the short GLC retention time of the derivative and interferences from the reagents at the lower levels.
Collaborative Study of the Determination of Endosulfan, Endosulfan Sulfate, Tetrasul, and Tetradifon Residues in Fresh Fruits and Vegetables
Authors: Mitchell Lawrence R 
Published: February 2020

Abstract
A method for the determination of endosulfan I, endosulfan II, endosulfan sulfate, tetrasul, and tetradifon residues in fresh fruits and vegetables was studied collaboratively. The method consists of extraction of the product with acetonitrile, extract cleanup by partition with petroleum ether and elution from a Florisil column with mixtures of hexane, methylene chloride, and acetonitrile, and determination of the residues by electron capture gas-liquid chromatography. This method was studied by 8 collaborators, using apples and cucumbers as the samples. Each sample was spiked with 2 levels of each pesticide. The average per cent recoveries for apples and cucumbers, respectively, were as follows: endosulfan I, 103.6 and 101.5; endosulfan II, 102.9 and 100.0; endosulfan sulfate, 100.9 and 92.9; tetrasul, 98.8 and 102.2; and tetradifon, 106.4 and 101.9. The method has been adopted as official first action.
Collaborative Study for the Comparison of Two Methods for the Determination of Total Cholesterol in Multicomponent Foods
Authors: Punwar Jalam K 
Published: February 2020

Abstract
The gas chromatographic method for determining total cholesterol in multicomponent foods, collaboratively studied by the AOAC in 1974 (Method 1), has been evaluated by 9 collaborating laboratories and compared with the Interim Methodology Instructions No. 2 modified method (Method 2). The 5 samples selected for collaboration were deviled ham sandwich spread, vegetable beef stew, frozen chicken pot pie, frozen fish sticks, and mayonnaise. The recovery data were obtained from a sample of wheat germ oil spiked with 0.297 % cholesterol as cholesteryl palmitate. Collaborators performed 2 replicate analyses on all samples by both methods. The statistical evaluation of the results showed that Method 1 is superior to Method 2. Average recoveries from the spiked wheat germ oil samples were 91.4% (9 laboratories) and 85.8% (7 laboratories) with coefficients of variation of 12.5 and 14.4%, respectively. Based on the collaborative results and statistical evaluation, Method 1 has been adopted as official first action.