bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gas-Liquid Chromatographic Method for the Analysis of Carbaryl Insecticide Formulations
Authors: Weyer Lois G 
Published: February 2020

Abstract
A gas-liquid chromatographic method has been developed for the direct analysis of Sevin (carbaryl, 1-naphthyl N-methylcarbamate) technical grade, Sevin 85, Sevin 80, and Sevin 50 formulations. The method consists of dissolving the sample in chloroform containing Thiodan as an internal standard; an aliquot of the supernate is injected into a gas chromatograph with a flame ionization detector and a column packed with 3% SE-30 on 60-80 mesh Gas- Chrom Q. The method compares favorably in accuracy with older methods, is not subject to interferences, is rapid, and has automation possibilities.
Determination of Brominated Vegetable Oils in Soft Drinks by a Combination of Total Bromide Estimation and Gas-Liquid Chromatography
Authors: Conacher Henry B S , Chadha Rajinder K 
Published: February 2020

Abstract
A procedure is presented for the determination of brominated vegetable oils in soft drinks by a combination of total bromide estimation and gas-liquid chromatography (GLC). The method for bromide estimation involves conversion of organic bromide to inorganic bromide by potassium hydroxide fusion, followed by iodometric titration of the inorganic bromide. The bromide content of several common brominated oils ranged from 33.5% (olive) to 43.9% (soybean). Recoveries, based on bromide content, on an orange drink fortified with brominated sesame oil in the range 1–25 mg/10 fluid oz were 94.3–97.5%. Used alone, this technique will not provide accurate brominated oil determination unless the identity of the oil is known. The latter can be deduced from GLC. The analysis of 6 citrus-based soft drinks, using the combined procedures, showed that 5 drinks contained brominated oil in the range 3.1–5.2 mg/10 fluid oz; none was detected in the other drink.
Microbiological Assay of Oleandomycin in Feed: Collaborative Study
Authors: Mayerhofer Hans J , Thompson Sherrill J 
Published: February 2020

Abstract
The present official final action AOAC method of analysis for oleandomycin in feeds, 38.204–38.207, was modified and collaboratively studied. The modifications consist of elimination of the compensating standard curve, changes in the curve point concentrations, and a change in the plating medium. Ten collaborators assayed 4 feed types each at 3 levels of fortification ranging from 1.8 to 18.2 g/ton. All feeds were tested for 2 days, 2 weights per day. The average mean recovery for all feeds at all levels was 92.3% (ranging from 90.11% at the 1.82 g/ton level to 93.51% for the 18.17 g/ton level). The coefficients of variation ranged from 18.2 at the 1.82 g/ton level to 9.3 at the 18.2 g/ton level. The assay variation for all collaborators was 12.5%. No statistically significant differences were found between feed types, levels, and collaborators at the 95% confidence level. This method has been adopted as official first action for the assay of oleandomycin at levels ≤2 g/ton.
Sensitivity Enhancement by Programmed Multiple Development in Thin Layer Chromatography
Authors: Perry John A , Glunz Louis J 
Published: February 2020

Abstract
Programmed multiple development (PMD) is an automatic, cyclic method for a new type of multiple development in thin layer chromatography (TLC). PMD instrumentation allows any number of samples to be developed identically, automatically, and simultaneously. PMD, given equal time of development with respect to conventional TLC development, yields a sensitivity enhancement for major components (in the sample to be detected) of about 10, given also the same sample quantity. The resolution of PMD chroniatograms does not reflect either spot size or overloading up to at least a factor of 20; thus PMD accommodates auxiliary techniques for sensitivity enhancement. The ultimate PMD sensitivity enhancement for traces of substances has yet to be determined.
Collaborative Study of an Automated Method for the Determination of Nitrogen in Meat Products
Authors: Gantenbein Walter M , Schermerhorn Jon L , George Elmer 
Published: February 2020

Abstract
An automated method for nitrogen in meat products was studied collaboratively. Samples were solubilized in sulfuric acid (1 + 1) , cooled to room temperature, and presented to an automated system. Digestion, dilution, and colorimetric measurement of the nitrogen were performed automatically. Samples were also analyzed by the official final action AOAC method, 24.010. Eight collaborators representing 6 laboratories participated in the study. Each participant analyzed 9 different samples in duplicate. Results of the study were satisfactory with an average range of 0.5% protein, average standard deviation of ±0.21%, and average coefficient of variation of 1.20%. The method was found to be as accurate as 24.010 and applicable to meat and meat products containing 0.8–4.0% nitrogen (5.0–25% protein). It has been adopted as official first action.
Study of the Occurrence of Ochratoxin A in Green Coffee Beans
Authors: Levi Colette P , Trenk Hugh L , Mohr Herman K 
Published: February 2020

Abstract
Moldy green coffee beans were found to contain Aspergillus ochraceus and detectable levels of ochratoxin A. The official first action method for the detection of ochratoxins in barley, 26.C15–26.C22, was modified for analysis of coffee beans and a number of survey samples of coffee beans were analyzed. A. ochraceus was found to be present in almost all samples but ochratoxin A was infrequently observed. Ochratoxin A production in sterile green coffee beans inoculated with A. ochraceus under optimal conditions was maximal at 13 days at room temperature but the total amount was low (450 μg/kg). Considerable destruction (approximately 80%) of ochratoxin A occurred during a heat treatment which simulated the roasting of coffee beans.
Pseudomonacidal Activity of Phenolic Disinfectants in Hard Water
Authors: Winicov Murray , Schmidt William , Palochak Muriel 
Published: February 2020

Abstract
Claims for pseudomonacidal activity under use conditions must be validated by hard water performance. Effective phenolic products can be formulated by using o-phenylphenol (OPP) as the principal active ingredient. In tap water containing calcium or magnesium ions, OPP is more effective than any high phenol coefficient phenolic ingredient. Such OPP compositions as are properly formulated with high activity phenolics require a use-dilution concentration providing at least 450 ppm OPP and not less than 750 ppm total phenolics to pass the AOAC use-dilution confirmation test, 4.011, against the 3 principal test organisms in the presence of 400 ppm hard water. Phenolic-based disinfectant products, providing use-dilution OPP concentrations up to 600 ppm and total phenolic concentrations up to 900 ppm, with validated hard water claims are now commercially available. An OPP standard formula is proposed which can be diluted to provide pass/fail usedilutions–a step in the direction of achieving uniformity among different testing laboratories.
Vitamin A in Mixed Feeds, Premixes, and Foods: Collaborative Study
Authors: Parrish Donald B 
Published: February 2020

Abstract
The official final action method for determining vitamin A in mixed feeds, 39.008–39.013, was simplified where possible, principally in extraction and transfer procedures and by omission of chromatography, and was modified to apply to a larger variety of feed and food products. Twenty-two analysts of various degrees of experience participated in the collaborative study of the method, using 6 products. After outliers were eliminated by the Dixon test, data were analyzed and averages were compared with amounts of vitamin A known to be, or estimated, in each sample. The average, per cent deviation from added amount, standard deviation, and coefficient of variation, respectively, on each sample were: breakfast cereal (Sample 1), 23.8 μg/g, 2% less, 3.08, 13% ; mixed feed (or premix), 12.6 μg/g, 5% less, 0.99, 8%; mixed feed containing carotenoid pigments (Sample 3 ), 4.5 μg/g, 3% more, 0.66, 15%; mixed feed without pigments, 4.5 μg/g, 3% more, 0.57, 13% ; liquid feed supplement, 11.4 μg/g, 9% less, 1.44, 12%; powdered breakfast drink, 19.6, 7% less, 1.91, 10%. Some analysts did not correct for pigments in Samples 1 and 3, or for losses on analysis, which could account in part for the degree of variation and for the lower values on some samples. The method has been adopted as official first action to replace 39.008-39.013.
Rapid Screening Method for Simultaneous Determination of Organochlorine and Organophosphate Pesticide Residues in Wheat by Gas-Liquid Chromatography
Authors: Levi Iser , Nowicki Thomas W 
Published: February 2020

Abstract
A previously reported gas chromatographic method for screening of organochlorine residues in wheat has been modified to permit rapid simultaneous screening for common organochlorine and organophosphate residues in wheat. Ground wheat is extracted by ball-milling with ethyl ether-hexane (3+97). The extract is divided into 2 equal portions. One half is used without cleanup for determination of organophosphates by flame photometric detection. The other half is cleaned up on Florisil prior to determination of organoehlorines by electron capture detection. The mean average recovery of 9 organoehlorines from wheat fortified at 0.50 ppm was 80%. Wheat analyzed immediately after treatment with 15 organophosphates showed an average mean recovery of 93%. After 8 weeks' storage, 9 of 15 organophosphates were recovered in excess of 60%, with an average mean recovery of 90% at the 1.00 ppm fortification level. The average mean recovery for 9 organophophates was 7% lower for extraction by ball-milling with ethyl etherhexane than for Soxhlet extraction with methanol- chloroform (10+90).
Collaborative Study of a Method for Organophosphorus Pesticide Residues in Apples and Green Beans
Authors: Laski Ronald R 
Published: February 2020

Abstract
Ten laboratories took part in a collaborative study of a method for organophosphorus pesticide residues in apples and green beans. Six representative organophosphorus pesticides or oxidation products were determined in duplicate at a different level on each crop. The average recovery of the pesticides, using the gas chromatographic potassium chloride thermionic detection system, had the precision and accuracy expected for parathion, paraoxon, carbophenothion oxygen analog, carbophenothion, and EPN. Interference due to reagents made quantitation of dimethoate inaccurate. The average recovery (%) of the pesticides on apples and beans, respectively, was as follows: dimethoate 125.1 and 112.9; paraoxon 99.3 and 103.7; parathion 86.5 and 92.2; carbophenothion oxygen analog 96.7 and 100.1; carbophenothion 88.8 and 102.6; and EPN 90.8 and 98.3. A separate part of the study involved a comparison between the potassium chloride thermionic gasliquid chromatographic detector and the phosphorus- specific flame photometric detector. A statistical analysis of the results obtained from 5 laboratories indicated that the 2 detection systems were equivalent in both precision and accuracy.
Determination of Sorbic Acid in Wine
Authors: Caputi Arthur , Ueda Masao , Trombella Bruno 
Published: February 2020

Abstract
A survey of a number of laboratories engaged in wine analysis showed that 2 basic techniques were used for the determination of sorbic acid. The first utilizes the absorbance by sorbic acid at 260 nm in acidic solution and the second depends on the oxidation of sorbic acid to malonaldehyde which is then reacted with thiobarbituric acid. The resulting red color is measured at 532 nm. A modification of the thiobarbituric method has been adopted by AOAC for the determination of sorbic acid in cheese. We found it could be successfully utilized for sorbic acid analysis in wine with minor changes. It was necessary to separate the sorbic acid from wine by steam distillation prior to either determination. The standard Cash wine volatile acid still is adequate for this purpose and over 9 9% acid could be recovered from a 2 ml wine sample in 200 ml distillate. We studied various parameters in both techniques and arrived at practical procedures for each. Both methods gave acceptable results and we recommend that they be subjected to a collaborative study.
Gas-Liquid Chromatographic Determination of Anethole in Liqueurs
Authors: Parker Robert G 
Published: February 2020

Abstract
In the method described, anethole is extracted from the liqueur sample with chloroform, which eliminates interference from the large amount of sugar present, and is determined by gas-liquid chromatography, using 10% K-20M Carbowax as stationary phase on Chromosorb W (AWDMCS) as solid support. Anethole concentrations were measured in 8 different bottle samples, consisting of 4 different brands produced by 3 different manufacturers. There is a significant difference in the anethole concentration for the 4 brands tested.
Effect of Light on the Extraction of Lead and Cadmium from Glazed Ceramic Surfaces
Authors: Krinitz Benjamin 
Published: February 2020

Abstract
The effect of light on the teachability of cadmium and lead from glazed ceramic surfaces was investigated. Two sets of ceramic plates containing different levels of acid-extractable cadmium when tested by the official AOACASTM method were selected for study. Light had essentially no effect on the extractable lead level; however, the amount of cadmium extracted was dependent on the amount of light present during the leaching process. The amount of cadmium extracted in the presence of light was 1–5 times the amount extracted in the absence of light. The higher the initial cadmium level in darkness, the greater the influence of light. This photosensitive effect is presumed to be due to the presence of unprotected cadmium sulfide pigment in the glaze under test.
A Simple Pressurized Sampling System for Use Prior to Gas Chromatographic Analysis of Aerosol Cosmetics
Authors: Liem Dhiam H , Rundervoort Gerrit J 
Published: February 2020

Abstract
Pressurized sampling of liquids, such as aerosol hairsprays, prior to direct introduction into the gas chromatograph is possible with simple and inexpensive devices, namely, some plastic transfer pieces, a small empty all-glass aerosol container with a valve but without a dip tube, and a special gas syringe (0–25 μl) with a small sliding Teflon valve at the end. This method of sampling has been tested for reproducibility and reliability (coefficients of variation of 1.2% for propellants 11 and 12, 2.3% for ethanol, and 1.1% for dichloromethane). By using the proposed sampling method and a previously reported gas chromatographic method, a quantitative and total analysis of solvents and propellants in aerosol hairsprays can be completed in 1 hr. Fifty commercial aerosol hairsprays have been analyzed by using this system.
Cylinder Plate Assay for Lasalocid Sodium
Authors: Scheiner Jacob M , Cort Winifred M , Chen Jessica 
Published: February 2020

Abstract
A microbiological assay method is described for the determination of the coccidiostat lasalocid sodium in premixes and finished poultry feeds. Premixes are extracted with absolute methanol and diluted to assay range with 25% methanol in the final dilution. Feed samples are extracted with ethyl acetate and an aliquot is evaporated at 60°C. The residue is dissolved in hexane, the antibiotic is extracted with 75% methanol in water, and the extract is diluted to the assay range with a final methanol concentration of 25%. Microbiological activity by horizontal agar diffusion is measured by the cylinder plate technique with Bacillus subtilis ATCC 6633. Recoveries of drug from premix are quantitative. A correction is made for recovery from feeds which, in this laboratory, has averaged 82% for mash feeds and 75% for pellets at a level of 0.0075% lasalocid sodium. Bacitracin, lincomycin, 3-nitro-4-hydroxyphenylarsonic acid, ipronidazole, and a combination of sulf adimethoxine and ormetoprim at current use levels in feeds do not interfere.
Spectrophotometric Determination of Carbadox in Swine Feeds
Authors: Goras John T , Gonci Donald A , Murai Kotaro , Curley James E , Gordon Philip N 
Published: February 2020

Abstract
The assay method is applicable to samples containing 0.00110-0.0606% carbadox (methyl 3-(2-quinoxalinylmethylene)carbazate - N1, N4-dioxide) (10–550 g/ton). Carbadox is leached from the sample with chloroform-methanol (3+1), followed by a series of solvent-solvent extractions, column chromatography, and finally the spectrophotometric measurement of the carbadox content of the final solution at 420 nm. This treatment of the feed or feed supplement sample serves to isolate the carbadox from materials that might interfere in the spectrophotometric measurement. The method of standard addition compensates for a feed or feed supplement matrix effect in the assay. A water pretreatment step improves recovery of drug from pelleted feeds. Assay results for feeds and feed supplements that were prepared under carefully controlled conditions showed good agreement between the amounts of carbadox added and found. Multiple assay values for feeds containing 0.00551% carbadox exhibited a coefficient of variation of about 5%. Assay results for commercial feed and feed supplement samples indicated that the assay method is applicable to a wide variety of feeds and feed supplements.
Improved Gas-Liquid Chromatographic Method for Determining Ethylenethiourea in Plants
Authors: Nash Ralph G 
Published: February 2020

Abstract
In the improved method for determining ethylenethiourea (ETU) in plants, pentafluorobenzoyl chloride was substituted for trifluoroacetic anhydride derivatization of S-benzylated ETU. The resulting product (2-(benzylthio)-l- (pentafluorobenzoyl)-2-imidazoline) gave recoveries of near 100% and improved the electron capture gas-liquid chromatographic (GLC) response. The product can be cleaned up by column chromatography to eliminate interfering GLC peaks. Soybeans grown in soil treated with 14C-ETU resulted in a high concentration of 14C residues in leaves, but only traces of ETU were detected by either 14C or GLC measurements.
New, Improved Thin Layer Chromatography for Poly chlorinated Biphenyls, Toxaphene, and Chlordane Components
Authors: Ismail Raja J , Bonner Frances L 
Published: February 2020

Abstract
Reverse phase partition thin layer chromatography is described for the separation of the different components in polychlorinated biphenyl compounds, chlordane, and toxaphene. Plates prepared from washed aluminum oxide, with silver nitrate incorporated into the layer, are saturated with a nonpolar solvent (immobile phase), air-dried overnight, and spotted. A mixture of polar solvents is used as the mobile phase. After exposure to longwave ultraviolet light, dark blue silver chloride spots form on a white background. As little as 1 μg Aroclor can be detected by this method, which can be applied for qualitative and semiquantitative measurements. Distinct patterns are obtained for Aroclor reference materials which are resolved from most DDT analogs and other commonly occurring chlorinated pesticides. Since the use of infrared, ultraviolet, nuclear magnetic resonance, and mass spectroscopy as supplementary methods for qualitative analysis involves a large capital outlay which is often beyond the resources of small laboratories, the technique is most valuable to the chemist in such laboratories where time and money are important factors.
Gas-Liquid Chromatographic Determination of Vitamin D2 in Multiple Vitamin Tablets Containing Minerals and Vitamin E Acetate
Authors: Edlund David O , Filippini Florido A , Datson James K 
Published: February 2020

Abstract
A gas-liquid chromatographic procedure used to determine vitamin D2 in multiple vitamin tablets has been modified to make it applicable for analysis of multiple vitamin tablets containing minerals and vitamin E acetate. The procedure modifications involve pre-extraction with ether, solution in an alcoholic sulfuric acid-pyridine mixture, and column chromatographic separation on phosphate-treated alumina. The modified procedure has been statistically evaluated. A 2.2% coefficient of variation and 100.3% average recovery were obtained for the samples evaluated.
Collaborative Study Comparing Two Methods for the Determination of Aflatoxins in Pistachio Nuts
Authors: DiProssimo Vincent 
Published: February 2020

Abstract
Two official first action methods for the determination of aflatoxins in peanuts and peanut products, method I (26.015-26.020) and method III (26.026-26.030), were modified slightly for the analysis of pistachio nuts. Thirteen collaborators analyzed naturally contaminated in-shell pistachio nuts, aflatoxin-free pistachio nuts, and pistachio nut composites spiked with known amounts of aflatoxins. The extraction and cleanup in method III are relatively simple and require no chromatography, whereas the lengthier method I employs column chromatography, producing a cleaner thin layer chromatographic extract. On the basis of the collaborative results obtained, both methods have been adopted as official first action for the determination of aflatoxins in in-shell pistachio nuts.
Rabbit Skin Test for Estimation of T-2 Toxin and Other Skin-Irritating Toxins in Contaminated Corn
Authors: Chung Choong W , Trucksess Mary W , Giles Albert L , Friedman Leonard 
Published: February 2020

Abstract
A rabbit bioassay test has been developed which can be used for screening large numbers of field samples of corn for T-2 and other toxins. Two μl each of the control solutions, 0.005–0.12 μg standards, and about 12 samples in ethyl acetate were applied simultaneously to the closely clipped skin of a 2–3 kg young rabbit. The skin reactions were read at 24, 48, and 72 hr. The prominent features of the reactions were erythema, edema, and necrosis. The T-2 toxin equivalences of the samples were estimated by the degree of the skin reactions caused by the standards. The method is reliable to at least 0.01 μg/test or 50 ppb. Graded response to the toxin is dependent upon the use of sensitive animals and properly diluted samples and standards. Rabbits were more sensitive than weanling rats or young guinea pigs, and the method showed better reproducibility with rabbits. Citrinin and zearalenone (F-2) showed negative skin reactions when applied at a level of 20 μg/skin site. They also showed poor skin reactions when administered by intradermal injection into rabbit skin. However, all 3 mycotoxins showed distinct skin reactions in guinea pigs by the intradermal route. The test was as sensitive as the topical test using rabbits with T-2 toxin. The prominent feature of the skin reaction was induration.
Colorimetric Estimation of Novatropine in Pharmaceutical Preparations
Authors: Karawya Mohamed S , Ghourab Mohamed Galal , Mohamed Ibtisam H 
Published: February 2020

Abstract
Novatropine (homatropine methylbromide) is estimated colorimetrically on the basis of the formation of a colored complex with bromothymol blue. As much as 100 μg novatropine/ml can be estimated in various pharmaceutical preparations without interference from other ingredients.
Determination of Docosenoic Acids in Fats and Oils by Gas-Liquid Chromatography
Authors: Conacher Henry B S , Chadha Rajinder K 
Published: February 2020

Abstract
A rapid gas-liquid chromatographic (GLC) procedure has been developed for the determination of docosenoic acids in fats and oils. The method involves conversion of a known weight of oil to methyl esters using sodium methoxide-methanol, with a known weight of methyl tetracosanoate used as an internal standard. After acidification and extraction into hexane, esters are analyzed by GLC on a diethylene glycol succinate column. The percentage of docosenoic acids is calculated from the docosenoate and internal standard peak areas. The method is particularly suited to the determination of low levels (&lt;5%) of docosenoic acids.