bluuebunny/crossref_metadata_2025_split huggingface dataset:
Residues in Eggs from Low Level Feeding of Five Chlorinated Hydrocarbon Insecticides to Hens
Authors: Cummings J G , Zee K T , Turner V , Quinn F , Cook R E 
Published: February 2020

Abstract
Sixty laying hens were carried for 20 weeks in a study designed to show the residue levels in eggs from birds maintained on feed containing 0.05, 0.15, or 0.45 ppm of lindane, heptachlor epoxide, dieldrin, endrin, and DDT in combination, and to show the rate of decline of residues in eggs during a one month withdrawal period. A rapid method for analysis of eggs based on electron capture gas chromatography and the one-step Florisil cleanup of Stemp and coworkers is described. Dieldrin and heptachlor epoxide showed the greatest propensity for storage in eggs, followed in order by endrin, p,p′-DDT, and lindane. There was a significant increase of DDE in eggs from birds fed DDT. Only lindane residues returned to the background level within the one-month withdrawal period.
Quantitative Calculation of Gas Chromatographic Peaks in Pesticide Residue Analyses
Authors: Gaul Jean A 
Published: February 2020

Abstract
Comparison of five methods for calculating gas chromatographic peaks (disc integration, triangulation, peak height × width at half height, Rt × peak height, and peak height) shows no significant difference in the calculated results when aldrin, heptachlor epoxide, and dieldrin are injected into a gas chromatograph equipped with electron capture detector.
Problems are associated with the calculation of toxaphene, chlordane, DDT, and BHC The author makes suggestions for calculating these four residues when present individually and in combinations with other pesticides. Use of the last fovir toxaphene peaks compares favorably with results obtained by vising the entire toxaphene curve. A method for calculating DDT in the presence of toxaphene, based on the construction of “parallel lines”, gives 89–100% of the DDT in the presence of 1–10 parts of toxaphene. Results for chlordane obtained by adding heights of individual chlordane peaks are shown to be close to results obtained with an integrator. When electron capture detection is used for determining the α, β, γ, and δ-isomers of BHC, the response of the β-isomer is fovmd to be approximately 50% less than response of the other isomers, thus pointing up the need for use of individual BHC isomers for electron capture gas-liquid chromatography quantitation.
Collaborative Test of a Microbiological Assay for Low Chlortetracycline Concentrations In Final Feeds
Authors: Abbey Anthony 
Published: February 2020

Abstract
Commercial poultry, cattle, and swine feeds, containing low levels of chlortetracycline (CTC) activity (5, 10, and 20 ppm CTC), were assayed collaboratively in eight laboratories by compensating CTC standard curves prepared with diluent from sodium hypochlorite-inactivated animal feed extracts. The coefficients of variation for poultry, cattle, and swine feeds, individually, were 20, 13, and 10%, respectively. The combined data from those laboratories on both poultry and cattle feeds yielded a coefficient of variation of 12%, while the combined data from those laboratories assaying poultry and swine feeds gave a coefficient of variation of 15%. The inactivation of CTC in animal feed extracts by sodium hypochlorite plus heat appears to be operative in all eight laboratories.
Determination of Acetaminophen in Combination with Other Drugs
Authors: Levine Joseph , Hohmann John R 
Published: February 2020

Abstract
Acetaminophen can be separated from acidic, basic, and neutral solutions on a sodium carbonate-sodium bicarbonate column. Salicylamides and barbiturates are eluted in chloroform; acetaminophen is eluted in ether and measured spectrophotometrically.
Dilution Method for Mold Count of Catsup
Authors: Wildman John D 
Published: February 2020

Abstract
The method of diluting catsup with an equal volume of stabilizer solution previous to the application of the official method for mold count has been tried by twelve different analysts in eleven District laboratories of the Food and Drug Administration. The analysts were in general agreement that the dilution method was easier and more accurate than the official method. The method, with the exception of the method of preparation of stabilizer solution, is recommended for adoption as official, first action.
Gas Chromatography of Unsaponifiable Matter. IV. Aliphatic Alcohols, Tocopherols, and Triterpenoid Alcohols in Butter and Vegetable Oils
Authors: Eisner Jerome , Iverson John L , Firestone David 
Published: February 2020

Abstract
The unsaponifiable matter of butterfat, castor oil, cocoa butter fat, corn, cottonseed, linseed, milo maize, peanut, rice bran, safflower, soybean, and tung oils was fractionated on a Florisil column and the third fraction (tocopherols, high molecular weight alcohols, and triterpenoid alcohols) was gas chromatographed. This fraction showed three homologous series, tentatively identified as normal, iso- and/or anteiso-, and multiple branched chain alcohols. Each sample was examined before and after hydrogenation with Adams catalyst. Gas chromatograms from most of the oils displayed characteristic patterns which could be used to identify individual oils.
Improved Cleanup Method for Determination of Biphenyl in Citrus Fruits and in Biphenyl-impregnated Kraft Papers by Thin Layer Chromatography
Authors: Norman Shirley , Rygg G L , Wells A W 
Published: February 2020

Abstract
A simple, rapid, and efficient method has been developed for determining biphenyl in citrus fruit and in biphenyl-impregnated kraft papers. Biphenyl is separated from citrus tissue by steam distillation and from biphenyl-impregnated papers by solution in iso-octane. Plastic sheets coated with silica gel, to which a polyvinyl alcohol binder and a fluorescent indicator have been added, are used for cleanup by thin layer chromatography (TLC). The TLC spots are extracted and measured spectrophotometrically at 248 m/µ. Recoveries of added biphenyl ranged from 92 to 98%. The new method is simple and brief; it is more accurate than cleanup by oxidative degradation since the variable background is practically eliminated. The new method is easier and faster than the silicic acid chromatostrip technique, and is just as accurate.
Determination of Oxidative Metabolites of Dimethoate and Thimet in Soil by Emission Spectroscopic Gas Chromatography
Authors: Bache C A , Lisk D J 
Published: February 2020

Abstract
The conversion of dimethoate to its oxygen analog and the production of oxidative metabolites of Thimet in soil has been shown by using emission spectroscopic gas chromatography for their determination. Preparative thin layer chromatography was vised for prior separation of Thimet oxidation products. The sulfoxide and sulfone of Thimet were the major determinable products.
Automated Elution-Filtration Analysis of Anticholinesterase Organophosphorus Compounds on Thin Layer Chromatographic Scrapings
Authors: Ott Daniel E , Gunther Francis A 
Published: February 2020

Abstract
An automated analysis system for anticholinesterase organophosphorus compounds has been modified to include an automated elution-filtration technique for analysis of these compounds after thin layer chromatography. The entire method offers specificity previously unobtainable by automated anticholinesterase methods and is rapid when combined with a multiple spotter apparatus for thin layer chromatography.
The present method has been used to determine parathion residues in fortified canned peaches down to a level of 0.1 ppm.
Synthetic Organic Colors in Oils
Authors: Jones F B 
Published: February 2020

Abstract
A fast and simple method was developed for the separation and identification of micro amounts of 11 oil-soluble synthetic organic colors. The colors under study were D&C Red Nos. 17, 18, and 35; D&C Green No. 6; D&C Violet No. 2 ; D&C Yellow No. 11; Ext. D&C Blue No. 5; Ext. D&C Orange No. 4; Ext. D&C Red No. 14; and Ext. D&C Yellow Nos. 9 and 10. Results of the collaborative study were good, and the method is recommended for adoption as official, first action.
Estimation and Identification of Turpentine in Multi-Component Mixtures: Identification of Pure Turpentine
Authors: Saxton Wilbur L 
Published: February 2020

Abstract
Turpentine is separated from multi-component products by steam distillation, quantitatively determined by a titrimetric bromination, and identified by gas chromatography of the brominated product. The method is satisfactory for each of the three types of turpentine produced in the U.S. but does not distinguish among them. Twenty-five samples of turpentine, representing the three main types, obtained from various sources, were assayed by the proposed method to determine range of titration value and the mean titration value. Recovery of turpentine from three products containing known added amounts were 83, 100, and 104%. The 25 samples of turpentine and 10 samples of commercial products known to contain turpentine all gave similar gas chromatographic curves. Curves show that a combination of peaks lying between 0.5 and 0.85 retention time (relative to aldrin) can be used to identify turpentine.
Factors Affecting the Precision of Moisture Measurement in Grain and Related Crops
Authors: Hunt W Haward , Neustadt M H 
Published: February 2020

Abstract
Moisture content is one of the most important factors affecting the quality of grain. Many types and makes of moisturemeasuring devices have been tested to establish a practical method of moisture measurement. Oven methods, used as standards to calibrate these devices, are empirical. Factors affecting the precision of moisture determinations by oven methods are discussed in detail. Since the relationship between moisture content and electrical properties may vary considerably at times, factors affecting the accuracy of electrical moisture meters are also discussed.
Analysis of Dairy Products for Chlorinated Insecticide Residues by Thin Layer Chromatography
Authors: Moats William A 
Published: February 2020

Abstract
Butterfat and milk samples were analyzed for chlorinated insecticides by thin layer chromatography (TLC) on aluminum oxide or silica gel plates containing a small amount of silver nitrate. The adsorbent was washed with distilled water before preparing the plates. A one-step cleanup on a partially inactivated Florisil column was performed prior to TLC analysis. For color development, the TLC plates were sprayed lightly with hydrogen peroxide to suppress possible interference from fat and then steamed before exposure to ultraviolet light to accelerate and intensify the color reaction. Rf values for a number of solvent systems on aluminum oxide and silica gel plates are given. With this procedure, 0.05 μg or less of insecticide can be detected in a 0.4 g butterfat sample or the extract from 10 ml milk.
Chemical Assay and Isolation of Chick Edema Factor in Biological Materials
Authors: Campbell T C , Friedman L 
Published: February 2020

Abstract
In the chemical assay for the chick edema factor (CEF) in biological material, the unsaponifiable matter containing the CEF is recovered from the saponification mixture and is cleaned up by column (alumina adsorption) and thin layer (silica gel adsorption) procedures. The final extract is analyzed on an electron capture gas chromatograph, and the chromatogram peaks are compared to a known standard. Recovery is good, and the approximate limit of detection is 0.2 ppb. Two CEF components that have been isolated as crystalline materials correspond to Peaks 4a and 7 of previously isolated material. The UV absorption maximum for the crystalline material is 242 mμ.
A Gas-Liquid Chromatographic Method for the Determination of Cyclohexylamine Sulfamate Salts in Animal Excreta
Authors: Derse Philip H , Daun Robert J 
Published: February 2020

Abstract
A relatively rapid, quantitative method for the determination of cyclamates in urine and feces is reported here. Rats maintained at various levels of cyclamate for 20 weeks excrete percentages of cyclamate based on the levels fed, either as the sodium or calcium salt; less sodium cyclamate is excreted than calcium cyclamate and most of the salt is excreted in the feces. Preliminary work indicates that with certain modifications, the method can be applied to the analysis of cyclamate in animal tissue at the level of a few parts per million.
Determination of Unsaponifiable Residues in Milk
Authors: Teague Robert T , Joe Frank L 
Published: February 2020

Abstract
Unsaponifiable residues are determined in milk samples by the following procedure: oily drug bases and fats are extracted with iso-octane (rather than the usual mixed ether solvents) in an alkaline alcohol-acetone mixture; this extract is concentrated and the fatty constituents are saponified with KOH. The unsaponifiable matter is then re-extracted with iso-octane and the residual soaps and extraneous constituents are removed by water washing and column chromatography. Mineral oil added at levels of 12–404 ppm to milk samples was quantitatively recovered, with an average value of 98%. Unsaponifiable matter in market milk was also determined; results demonstrated good precision between duplicate analyses. Milk-out studies were performed to determine the rate of diffusion and dissipation of infused formulations.
Determination of Secondary and Minor Plant Nutrients in
Fertilizers by Atomic Absorption Spectrophotometry:Third Collaborative Study
Authors: Mcbride C H 
Published: February 2020

Abstract
The atomic absorption procedure, 2.086— 2.091, was studied further and expanded to include Ca, Na, and K. Examination of 7 samples by 19 collaborators resulted in between-laboratory precision of 4—7% in the range of concentrations of agronomic interest for Cu, Fe, Mg, Mn, and Zn. The method is recommended for adoption as official, first action for Ca. Further study of the method for K and Na is recommended.
Mechanisms of Sampler Bias
Authors: Baker W L , Gehrke C W , Krause G F 
Published: February 2020

Abstract
Possible mechanisms of sampler bias on dry mixed fertilizers were evaluated in an effort to develop better official sampling instruments and procedures. Three lots of dry mixed fertilizer (about 1 ton each) with known physical and chemical composition were prepared in the laboratory. Twelve vertical and 12 horizontal cores, arranged in a latin square sampling pattern, were secured from each lot with 3 triers: the AOAC double tube trier, a double tube compartmented trier, and an experimental double half-tube trier wherein the core was encompassed in place rather than being required to flow into a compartment as with conventional triers. Individual cores were analyzed physically and chemically. Only marginally significant differences were found between cores on the basis of tube opening size. The experimental double half-tube trier was less selective to particle shape than either the compartmented or AOAC triers, but differences were not statistically significant. All triers produced more representative samples from vertical cores than from horizontal cores. Cores drawn at a 60—75° angle from horizontal were not consistently different from vertical cores. Results of chemical analysis confirmed the sieve analysis findings quite closely. Horizontal cores secured with the experimental double half-tube trier confirmed that the bias observed in horizontal cores was due to downward drifting of small particles when the core area was disturbed by sampler insertion. Cores secured with the sample-retaining face upward contained an excess of fines, while cores secured with the sample-retaining face to the side or downward more nearly resembled vertical cores in composition.
Sweep Co-Distillation Cleanup of Milk for Determination of
Organophosphate and Chlorinated Hydrocarbon Pesticides
Authors: Watts Randall R , Storherr Robert W 
Published: February 2020

Abstract
A rapid extraction and sweep co-distillation cleanup procedure is described for organopliospbate and chlorinated pesticide residues in milk. Ethyl acetate and methanol are used as the extracting and the coagulating solvents, respectively. The extraction apparatus includes a graduated cylindrical separatory funnel which expedites sample handling. A suitable aliquot of the extract is concentrated in a Kuderna-Danish concentrator, sweep co-distilled for 30 min to remove the fat, and determined by GLC with the thermionic detector. Milk samples were fortified, on a whole milk basis, prior to extraction with three different pesticide standard solutions. The pesticide solutions contained as follows: (2) diazinon, methyl parathion, malathion, parathion, and Trithion; (2) Thimet, ronnel, ethion, Imidan, and Cuthion; and (3) lindane, heptachlor, aldrin, heptachlor epoxide, dieldrin, endrin, and p,p'-DDT. Average recoveries of these pesticides were generally 90+%. Sensitivity of 0.01 ppm was readily obtainable for pesticides such as parathion
Field Weathering of Toxaphene and Chlordane
Authors: Klein A K , Link J D 
Published: February 2020

Abstract
Both toxaphene and chlordane are rapidly lost on kale and presumably on other vegetables by weathering. Only trace amounts remain from an initial heavy application after 28 days. During this period the composition of the pesticides changes. With toxaphene, even at low levels, the remaining components appear to be organic chlorine compounds. The revised colorimetric method for toxaphene gives satisfactory results and supplements gas chromatography when the toxaphene level is not lower than 10 ppm or perhaps 5 ppm. The colorimetric method is not applicable at levels of 1 ppm or less. Large amounts of DDT interfere with the proper evaluation of the toxaphene by gas chromatography. Chlordane interferes seriously in both methods
Extraction of Chlorinated Pesticide Residues from Nonfatty
Samples of Low Moisture Content
Authors: Bertuzzi Patricia F , Kamps Laverne , Miles Corbin I , Burke Jerry A 
Published: February 2020

Abstract
A study using samples with field-incurred residues of chlorinated pesticides showed that acetonitrile alone is not effective for extracting the pesticide residue from samples containing about 10% moisture. Investigation of a variety of solvents resvilted in the choice of 35% water/acetonitrile as the most effective extractant. Other variables of the extraction studied were sample size, extractant volume, sample grinding, and blending time. The extraction system chosen compared well with an exhaustive extraction technique previously demonstrated to completely remove residues of chlorinated pesticides. Results are given for the extraction of field-incurred residues of five pesticides from three commodities. A procedure for extracting "dry" samples is outlined
Metabolism of DDT and Some Other Chlorinated Organic Compounds by Aerobacter aerogenes
Authors: Mendel J L , Klein A K , Chen J T , Walton Mae S 
Published: February 2020

Abstract
The micro-organism, Aerobacter aerogenes, reductively dechlorinates o,p'-DDT to o,p'-DDD. The yield is constant for a constant 24-hour incubation period. This metabolic pathway appears to be rather specific for the DDT's, since Perthane is not produced from l,l,l-trichloro-2,2-bis(pethylphenyl) ethane even after long incubation with A. aerogenes. In general, incubation of methoxychlor with the bacterium results in loss of the pesticide: its olefin and the reductively dechlorinated pesticide [ (l,l-dichloro-2,2-bis (p-methoxyphenyl) ethane] are sometimes produced but only after long term incubation. A. aerogenes does not effect the conversion of aldrin to dieldrin.
Determination of Starch and Soluble Carbohydrates. II. Collaborative Study of Starch Determination in Cereal Grains and Cereal Products
Authors: Friedemann Theodore E , Witt Norman F 
Published: February 2020

Abstract
The method of Friedemann, Witt, and Neighbors for starch in cereal foods was studied collaboratively on 12 samples by 8 laboratories. Results were compared with those obtained in the Associate Referee's Laboratory and were generally somewhat lower, probably because of inexperience with the method. The method is recommended for adoption as official, first action.
Persistence of Sevin Residues on Some Vegetable Crops After Various Harvest Times
Authors: Elessawi Makarem Ahmed , El-Refai Abdel Rahman 
Published: February 2020

Abstract
Chemical analysis of edible portions of untreated okra, cowpeas, tomato, and eggplant gave relatively low values for apparent Sevin. These crops were planted on experimental plots ( 4 X 4 meters), treated with multiple application of Sevin at the rate of 0.34% technical Sevin (60 g 8 5 % wettable powder/15 L water), and grown vinder simulated commercial practices. The Sevin residues were far below the tolerance level two hours after the final application. Higher initial and more persistent residues were found on okra and cowpeas than on tomato and eggplant crops. Maximum Sevin residues on okra, cowpeas, tomato, and eggplant were 3.2, 5.03, 1.88, and 1.88 ppm, respectively, 3 hours after the last application; these residues declined within 8 days to below 0.05 ppm in all vegetables
Correlation of Fatty Acid Structure With Preferential Order of Urea Complex Formation
Authors: Iverson John L , Weik R W 
Published: February 2020

Abstract
The selective order in which methyl esters of fatty acids form urea complexes was correlated with the fatty acid structure. Detailed information about the preferential order in which inclusion compounds are formed was obtained by fractionating complex oils (e.g., butter, lanolin, cod liver). The preferential order was correlated with GLC retention times, and the detection of trace amounts of fatty acids (&lt;0.1%) was possible. Urea adductability values (UAV) are proposed as a useful means of expressing preferential order of the formation of inclusion compounds
Detection of Solvents by Infrared Spectrophotometry
Authors: Schwartzman George , Sullivan Daniel , Sarnoff Evelyn 
Published: February 2020

Abstract
The solvent used in the recrystallization of a solid may be determined by use of the IR spectrum and gas cell. Recrystallized powders retain a minute amount of solvent which is not detectable in a KBr disk of the powder, but is detectable when a gas cell is vised. The following solvents were examined by this method: acetone, benzene, n-butanol, tert-butanol, carbon tetrachloride, chloroform, ethanol, ethyl acetate, ethyl ether, isopropyl alcohol, methanol, n-propanol, trichloroethylene, toluene.
Validation Study of a Method for Pesticide Residues in Foods and Animal Feeds
Authors: Wells Clyde E 
Published: February 2020

Abstract
Eighteen laboratories of the Food and Drug Administration tested a multi-pesticide residue method using 65 pesticides and 80 food and animal feed products. Recoveries of 32 pesticides averaged between 80 and 110%; 20 additional pesticides were recovered with some degree of success; and 13 of the pesticides tested were not recovered. The method tested is based on the AOAC procedure which involves extraction of the pesticides with acetonitrile, partition into petroleum ether, cleanup on a Florisil column, and gas-liquid chromatography. Recoveries were essentially independent of the type of product. Of the products tested, only carrots, parsnips, onions, and lettuce exhibited serious interference when the electron capture detector was used
Spectrophotometry Determination of Temik® Residues in Citrus
Authors: Meagher W R , Hendrickson R , SHIVELY B G 
Published: February 2020

Abstract
An improved spectrophotometric method for determining Temik residues in citrus has been developed by using an acetone extraction followed by a Florisil column cleanup to remove interfering svibstances. The method also determines the sulfone and sulfoxide metabolites of Temik and Temik oxime, but it does not differentiate between parent compound and/or its metabolites. An overall average recovery of 98.5 ± 2.2 % was obtained on samples fortified at levels of 0.002-0.200 ppm. As little as 0.0006 ppm Temik, based on a 500 g fruit sample, covdd be determined