bluuebunny/crossref_metadata_2025_split huggingface dataset:
Collaborative Study on the Determination of Aflatoxins in Cottonseed Products
Authors: Pons Walter A 
Published: February 2020

Abstract
Twelve laboratories collaboratively studied a method for estimating aflatoxins in cottonseed products, using both visual and fluorodensilometric estimation of aflatoxins on TLC plates. Average recovery of total aflatoxins (B1 + B2) added to five products was 85% by visual and 90% by densitometric estimation; average coefficients of variation were 18 and 12%, respectively. Within- and between-laboratory precision was essentially equivalent for both types of measurement, with no significant systematic errors among the laboratories. There was a high degree of correlation between visual and densitometric estimation of aflatoxins.
Reaction of Aflatoxin B1 with Acetic Acid-Thionyl Chloride
Authors: Wiley Mabry , Waiss Anthony C , Bennett Nancy 
Published: February 2020

Abstract
The two main products of the reaction of acetic aeid-thionyl chloride with aflatoxin B1, used as a confirmatory test for aflatoxin B1, were identified as the α- and β-isomers of l-acetyl-2-hydro-6-methoxydifurocoumarone
Collaborative Study of the Determination of Ethanol in Wine by Chemical Oxidation
Authors: Caputi Arthur , Wright Dawson 
Published: February 2020

Abstract
A collaborative study was conducted on a chemical or dichromate oxidation procedure for etlianol in wine. The method is based on the steam distillation of ethanol from a 1 ml wine sample into an acidified solution of potassium dichromate, followed by heating 20 min at 60°C to complete the oxidation of the ethanol to acetic acid. The unreacted dichromate is determined by titration with a standard ferrous ammonium sulfate solution, using o-phenanthroline as an indicator. Eleven collaborators participated in the study, of whom seven were familiar with the method and four were not. Eight samples with alcohol content ranging from 11.8 to 23.5% by volume were analyzed. The standard deviations of the reported answers on the identical samples varied from 0.024 to 0.063% in the range of 11.8–20% ethanol and rose to 0,161% in the sample which contained 23.3% ethanol by volume. This reproducibility is better than has been reported with other commonly used methods, and it is recommended that the method be adopted as official first action.
Analysis of Tritium in Water: A Collaborative Study
Authors: Sodd Vincent J , Scholz Kenneth L 
Published: February 2020

Abstract
A liquid scintillation procedure using 1,4-dioxane, naphthalene, PPO, and POPOP as the scintillator was evaluated in a collaborative study of the determination of tritium in water. The tritium counting efficiencies for seven collaborating laboratories using this technique and commercially available liquid scintillation spectrometers ranged from 8.3 to 26.5%. The minimum detectable activity by the method, based on 99% confidence limits, 100 min counting time, and backgrounds from 9 to 67 cpm, ranged from 0.2 to 0.5 pCi/ml. Statistical results showed no evidence for systematic error. The coefficient of variation varies from 3.4 to 7.3% over the concentration range 2.91–115.8 pCi/ml. It is recommended that the method be adopted as official first action.
Determination of Pentachlorophenol in Blood, Urine, Tissue, and Clothing
Authors: Barth W F , Curley August , Thrasher C L , Sedlak V A , Armstrong Robert 
Published: February 2020

Abstract
An epidemic with two deaths occurred in a nursery in St. Louis after the use of pentachlorophenol as a mildew preventive with the laundry detergent. Samples of blood, urine, tissue, and clothing from the nursery were extracted with ethyl ether. The ether solution was extracted with 5% sodium hydroxide; the basic solution was acidified and then extracted with benzene. The benzene solution was analyzed by electron capture gas chromatography, using a 3% diethylene glycol succinate column with 2% sirupy phosphoric acid on 60-80 mesh Chromosorb G. Pentachlorophenol was found in the samples in sufficient quantity to account for the epidemic. The presence of pentachlorophenol was confirmed by gas chromatogrifplryrmass spectroscopy and by thin layer analysis.
Determination of Mesurol and Five of Its Metabolites in Apples, Pears, and Corn by Gas Chromatography
Authors: Bowman M C , Beroza Morton 
Published: February 2020

Abstract
Mesurol and five of its metabolites were determined in apples, pears, and whole corn plants. The crop was chopped with buffer to prevent hydrolysis of some of the metabolites and then extracted with acetone. The extracts were separated by liquid chromatography on silica gel into sulfide, sulfoxide, and sulfone fractions, and each fraction was further subdivided into carbamate and phenolic fractions by liquid chromatography on alumina. After the carbamates were hydrolyzed to their respective phenols (because the carbamates decomposed partially during GLC), the phenols in each fraction were determined by GLC with a sulfur-sensing flame photometric detector. No significant interference from crop extracts occurred. Recoveries ranged from 68 to 106% and generally were 80% or better; sensitivities were about 0.01 ppm. A procedure for determining the conjugated phenols liberated by acid hydrolysis is also described.
Collaborative Study Comparing Gas-Liquid Chromatographic and Chemical Methods for Quantitatively Determining Vitamin E Content of Pharmaceutical Products
Authors: Sheppard A J , Hubbard W D , Prosser A R 
Published: February 2020

Abstract
A collaborative study was conducted to compare the USP XVII (Emmerie-Engel) method and three GLC methods for quantitatively determining a-tocopherol, a-tocopheryl acetate, and a-tocopheryl succinate in pharmaceutical products. Nine collaborating laboratories analyzed seven pharmaceuticals encompassing tablets, capsules, and liquids. The mean coefficients of variation were: USP method, 28.6%; GLC method A, 10.2%; GLC method B, 10.8%; GLC method C, 18.0%. GLC method A was the method of choice of those evaluated. The vitamin E analogs are extracted with n-hexane from ground tablets and capsules; liquid preparations are diluted with n-hexane or injected directly onto the GLC column. The compounds are chromatographed on an 8′ × 4 mm id glass column paeked with 5% SE-30 on 100-120 mesh silanized Gas Chrom P, operated between 270-285°C, and the carrier gas flow rate adjusted so that ∝-tocopheryl acetate appears within 23-27 min. Acetic anhydride-pyridine reaction is utilized to determine whether ∝-tocopherol or ∝-tocopheryl succinate is present in a sample, since these two analogs have similar retention times. It is recommended that GLC method A be adopted as official first action.
Detection and Identification of Salmonella from Dry Milk: Report of a Collaborative Study
Authors: Poelma P L , Wilson C R , Romero A , Padron A 
Published: February 2020

Abstract
A method for the detection and identification of Salmonella from dry milk was subjected to collaborative study. A 100 g sample is reconstituted in 1 L distilled water with 2 ml 1% aqueous brilliant green dye, incubated, subcultured in selenite cystine broth and tetrathionate broth, incubated, and streaked on selective plates of brilliant green agar, Salmonella-Shigella agar, and bismuth sulfite agar. After incubation, suspicious colonies can be further identified by biochemical and serological tests. Samples of nonfat dry milk and dry whole milk, some inoculated with Salmonella binza, Salmonella tvorthington, and Citrobacter, were examined by 30 collaborators. Results from 23 of 28 collaborators were in agreement; the method will detect and identify Salmonella from positive nonfat dry milk and dry whole milk. The method is recommended for adoption as official first action.
Gas Chromatographic Determination of Residues of Dimethoate and Its Oxygen Analog in Field-Sprayed Kale
Authors: Storherr R W , Watts Randall R 
Published: February 2020

Abstract
Significant residues of the oxygen analog of dimethoate were found when both 1.0 and 0.5 lb of active dimethoate/acre were sprayed on field-grown kale. At the 14 day sampling period, the residue ratio of dimethoate oxygen analog to dimethoate was 4:1 as determined by GLC, using a glass column packed with 2% diethylene glycol succinate (stabilized) on Gas Chrom Q and a potassium chloride thermionic detector.
Gas Chromatography of Organophosphorus Pesticides: Retention Times and Response Data on Three Columns
Authors: Watts Randall R , Storherr R W 
Published: February 2020

Abstract
GLC systems with potassium chloride thermionic detection are described for analysis of over 60 organophosphorus pesticides and alteration products. Each compound was chromatographed on three GLC columns: 10% DC-200, QF-1/DC-200 mixed, and 2% stabilized diethylene glycol succinate liquid phases on 80–100 mesh Gas Chrom Q support. Retention times and response data are shown for all the pesticides chromatographed on each of the three columns.
Charcoal Column Cleanup Method for Many Organophosphorus Pesticide Residues in Crop Extracts
Authors: Watts Randall R , Storherr R W , Pardue John R , Osgood Theodore 
Published: February 2020

Abstract
In the charcoal column cleanup method for organophosphorus pesticide residues in crops, the pesticides arc extracted from the crops with ethyl acetate and a 10–20 g aliquot is placed directly on the charcoal adsorbent column for cleanup. The Kuderna-Danish concentrated eluate is analyzed by GLC, using the potassium chloride thermionic detector. Analytical results are presented for pesticide field-treated crops and for crop extracts fortified with a total of 60 parent organophosphorus pesticides and alteration products. Recoveries averaged 90% or better in most cases.
Analysis of a Single Crop Extract for Substituted Urea Herbicides and Metabolites, Chlorinated Insecticides, and Amitrole
Authors: Onley John H , Yip George 
Published: February 2020

Abstract
An established method for chlorinated insecticides has been modified and extended to include substituted urea herbicides, some urea metabolites, and amitrole. Starting with an acetonitrile sample extract, chlorinated insecticides are removed by petroleum ether extraction for the usual cleanup and determination. The aqueous acetonitrile phase is next extracted with methylene chloride and carbon tetrachloride to isolate the urea compounds (chloroxuron, diuron, fenuron, fluometuron, linuron, metobromuron, monuron and neburon) and some of their metabolites. This combined extract is chromatographed on a MgO-cellulose-Florisil column from which two eluatcs are obtained: one contains the substituted urea herbicides, aniline metabolites, and one compound with the urea moiety and the second contains four compounds with the urea moiety. Both eluates are analyzed by thin layer chromatography. Finally, the aqueous acetonitrile extract is passed through a column of Amberlite IR-120 resin. Amitrole (3-AT), which is absorbed on the resin, is removed with NH4OH and determined by a colorimetric procedure. Recoveries of all compounds from samples fortified at 0.05–5 ppm ranged between 70 and 106%. Apparent limit of sensitivity was 0.05 ppm for both the substituted urea herbicides and their metabolites and for amitrole. Recoveries for the chlorinated insecticides at 0.005 ppm ranged between 76 and 104%.
Sampling Bulk Fertilizers in Railroad Cars and Piles
Authors: Gehrke Charles W , Baker Winfred L , Krause Gary F , Russell C H 
Published: February 2020

Abstract
The AOAC official samplers (stream sampler, compartmental triers, and Missouri “D” tube) secured samples of ammoniated granular fertilizers at all locations in railroad cars and warehouse piles that were well within the AAFCO tolerances. Dry blended fertilizers in lots of this size could not be sampled as outlined in this study. Recommendations are made for the sampling of fluid fertilizers (in absence of free ammonia).
Aflatoxins: Improved Resolution by Thin Layer Chromatography
Authors: Stubblefield R D , Shannon G M , Shotwell O L 
Published: February 2020

Abstract
Water was added to solvent systems for TLC of aflatoxins to achieve more reproducible results in laboratories where temperature and relative humidity vary. Resolution of the toxins also improved. Increments of water were added to solvent systems composed of acetone-chloroform (10 + 90, 12 + 88, and 15 + 85, v/v). As the water concentration was increased, separation of aflatoxins B2 and G1 improved. These two toxins are usually the most difficult to resolve in these solvent systems. Separations were the best with wateracetone-chloroform (1.5 + 12 + 88, v/v/v). Water added to methanol-chloroform (3 + 97, v/v) improved resolution of this solvent system but not enough for quantitative analysis, or at times, qualitative analysis. The solvent system water-methanol-ether (1 + 3 + 96, v/v/v) separated aflatoxins as well as water-acetone-chloroform (1.5 + 12 + 88, v/v/v).
Microbiological Assay of Erythromycin Thiocyanate in Feeds
Authors: Perdue H S , Gordon J A , Mannebach J 
Published: February 2020

Abstract
A modified procedure has been developed for extracting low levels (5-20 g/ton) of erythromycin thiocyanate from feeds. In the new method, erythromycin thiocyanate is extracted from the feed with acetone, the acetone is evaporated, and the extract is washed with n-hexane (5 parts) followed by methanol (1 part). The n-hexane and methanol washings are combined and partitioned with phosphate buffer prior to assay using Sarcina lutea ATCC 9341. Recovery averaged 106 ± 10%.
Microbiological Assay of Streptomycin in Feeds
Authors: Mayernik John J 
Published: February 2020

Abstract
Studies of the microbial assay of streptomycin were conducted to evaluate (1) four methods of preparing compensating standard curves and (2) a n IRC-50 resin separation method to overcome the interference of feed components in low level feeds. Compensating curves were prepared from extracts of blank feed, from extracts of feed in which streptomycin was adsorbed by IRC-50 in a batch method and also in a column method, and from extracts of feed by the method of standard addition. Recoveries of streptomycin using the extract of blank feed and extract of feed by the method of standard addition were promising (83–96%), whereas recoveries using IRC-50 resin-inactivated extract were low (47–62%). The IRC-50 resin separation method was found to be satisfactory in principle, but the interference of the feed components was not resolved. Further studies are planned on the compensation methods and the resin separation method.
Characterization of the Steam Nonvolatile Residue of Bergamot Oil and Some Other Essential Oils
Authors: Cieri Ugo R 
Published: February 2020

Abstract
A method is presented for identifying and estimating the coumarins and furocoumarins present in bergamot oil and four other essential oils. Solutions of the nonvolatile residue of the oils are spotted on silica gel thin layer plates and developed in hexane-ethyl acetate (75+25) for 4 hr. The separated compounds are identified by their Rf values and characteristic fluorescence under short wave UV light; the spots are marked, scraped from the plate, and extracted with chloroform. The centrifuged extracts are scanned in a recording spectrophotometer from 400 to 240 mμ. Bergaptene, citroptene, bergamottin, and 7-methoxy-5-geranoxycoumarin were also individually estimated. Bergaptol, isopimpinellin, and xanthotoxin could be estimated only roughly because of low absorbance readings or lack of standards. A procedure to isolate and purify bergamottin from bergamot oil and 7-methoxy-5-geranoxycoumarin from lime oil, to serve as reference standards, is also included.
Effect of Dilution on Mold Counts of Tomato Catsup
Authors: Schulze Arnold E , Eisenberg William V , Douglas Ruth G , Parran Hamilton M 
Published: February 2020

Abstract
Mold counts of samples from 34 catsup factories in the United States were made by two methods: a direct count and a 1 + 1 dilution. An average mold count on undiluted catsup of 44% (which is in a significant range) was reduced to an average of 35.5% on dilution. From factories with special comminuting equipment, a few samples showed greater reduction in mold count on dilution than samples produced with the conventional pulper and finisher; samples processed with an Urschel Comitrol in the FDA pilot plant showed less reduction.
Collaborative Study of a Colorimetric Determination of Nitrate in Tobacco
Authors: Rosene C James 
Published: February 2020

Abstract
A colorimetric method for determining water-soluble nitrate in tobacco was studied by 14 laboratories on eight Burley and two cigar filler tobacco samples with nitrate levels of 0.5–2.4%. In the method, ground tobacco is extracted with water and filtered, and an aliquot is then treated with 2,4-xylenol in sulfuric acid; then the resulting 6-nitro-2,4-xylenol is removed by distillation and measured spectrophotometrically at 450 µm. Results show that, althoughthe precision standard deviation among laboratories is generally acceptable, the systematic error standard deviation is unacceptably high. This study will be continued.
Extraction and GLC Determination of Mixed Sulfonamides in Feeds
Authors: Fravolini Arnaldo , Begliomini Alfredo 
Published: February 2020

Abstract
Seven sulfonamides added to feed samples were extracted with DMF and hydrolyzed to the amines with sulfuric acid. After alkalization, the extracts were analyzed by GLC, using a Carbowax 20M column. Recoveries averaged between 94 and 104%. The described method is rapid and requires a minimum of manipulations.
Nonaqueous Polarographic Analysis of Nitroglycerin
Authors: Woodson Albert L , Alber Larry L 
Published: February 2020

Abstract
The DC and AC polarographic response of nitroglycerin in the nonaqueous medium of acetonitrile-0.1M tetrabutylammonium perchlorate is presented. DC polarographic results are shown to be superior with respect to sensitivity limits and linearity of the response (wave height) vs. concentration profile. DC polarography is applied successfully to the analysis of two types of commercial formulations containing nitroglycerin. The results are compared with other methods for the determination of nitroglycerin, e.g., infrared, the phenoldisulisulfonic acid procedure for organic nitrates, and a column chromatographic procedure.
Chemical Composition of Florida Orange Juice Concentrates
Authors: Floyd Kermit M , Harrell Jimmy E 
Published: February 2020

Abstract
Authentic samples of Florida orange juice concentrates were analyzed for soluble solids, acidity, amino acids, polyphenolics, f-malic acid, and betaine. Samples were collected from various processing plants during January through May 1968. Authentic data and a statistical study are presented.
Determination of 2-Nitropropanol Residues in Cottonseed
Authors: Devine James M , Fletcher Barbara , Zweig Gunter 
Published: February 2020

Abstract
2-Nitropropanol, a metabolite of Lanstan, can be extracted from cottonseed with ethyl acetate and analyzed by electron capture GLC. The average recovery for fortification levels ranging from 0.05 to 0.2 p pm was 84.7 ± 11.1%. Lanstan does not interfere with this method because it elutes with the solvent under the GLC conditions used for analysis.
Elemental Analyses of Plant Leaf Tissue by Several Laboratorie
Authors: Jones J Benton 
Published: February 2020

Abstract
Eighteen laboratories reported the analyses of seven plant tissue referee samples for the elements N, P, K, Ca, Mg, Al, B, Cu, Fe, Mn, Na, and Zn. Agreement among the laboratories was good for the elements N, P, Mn, Mg, K, and Ca. Poor agreement was obtained for the elements B and Cu with only fair agreement for Na, Al, Zn, and Fe. The results from this exchange of samples were not too different from those obtained by others in similar studies. Although the probable sources for the variances were not investigated, failure to specify drying and ashing technique, as well as the lack of plant tissue standards from a reliable source, may have contributed to discrepant analyses in some laboratories. Also, analysts need to carefully evaluate calibration and operating techniques, particularly when emission spectrographs are used to perform plant tissue analyses. Exchange of plant tissue referee samples between laboratories can be of assistance to the analyst when plant tissue standards are not available.
Improved Method for the Analysis of Total Nitrogen and TCA-Precipitable Nitrogen in Tuberculin and Johnin Biologies
Authors: Czech Fred P , Sunseri Alfred P 
Published: February 2020

Abstract
Tuberculin is routinely tested for safety, potency, etc., including chemical tests for total and TCA-precipitable nitrogen content. The last two tests have large methodological errors. Methods obtaining greater accuracy and precision are presented and compared to present procedures; they are recommended as substitutes for existing methods.
Note on Detection and Quantitative Analysis of Cyclohexylamine
Authors: Gunner S W , O’Brien R C 
Published: February 2020

Abstract
CIIA is reacted with picryl chloride to form a stable crystalline N-trinitrophenyl derivative. This procedure eliminates CHA loss during sample work-up and, using GLC, permits detection in the subnanogram range with an electron capture detector. Quantitative analysis is achieved using 3,3,5-trimethylcyclohexylamine as internal standard and is illustrated by the analysis of CHA in cyclamate at a level of 1 ppm.
Survey of Chlorinated Insecticide Residue Analyses in Soils
Authors: Woolson E A , Kearney P C 
Published: February 2020

Abstract
Kecovery methods of 12 laboratories were compared for the extraction and detection of 11 chlorinated hydrocarbon insecticides in three soil types. Nine laboratories averaged 78% recovery (range 60–106%) with an average error of the mean of 21% and average coefficient of variation of 45%. Highest recoveries were obtained from wet samples extracted with hexane-acetone by Soxhlet extraction. Variability increased as concentration decreased below 1.00 p pm insecticide.
Head Space Gas Procedure for Screening Food Samples for Dithiocarbamate Pesticide Residues
Authors: Mcleod H A , Mccully K A 
Published: February 2020

Abstract
screening procedure has been developed for dithiocarbamate residues in foods. The CS2 evolved from an H2SO4-sample mixture at 60°C for 30 min was determined by GLC; recoveries of ferbam, thiram, and ziram added to apples, strawberries, lettuce, celery, cabbage, cucumber, and carrots ranged from 80 to 114% at 3.5 ppm and from 86 to 112% at 7 ppm. Recoveries of maneb, nabam, and zineb were not satisfactory. When an HCl-stannous chloride reagent was substituted for the H2SO4 reagent, recoveries of the ethylenebisdithiocarbamates were considerably improved. Maneb and ziram recoveries ranged from 70 to 95% in all samples; ferbam, thiram, and ziram, from 84 to 100%; and nabam, from 44 to 83%. The difference between duplicate recovery values, using the latter reagent, ranged from 0 to 11.2% units; 87% of these values were less than 10%.
Rapid GLC Method for Determining Residues of Fenthion, Disulfoton, and Phorate in Corn, Milk, Grass, and Feces
Authors: Bowman M C , Beroza Morton 
Published: February 2020

Abstract
Residues of fenthion, disulfoton, and phorate may each consist of the parent insecticide and five metabolites formed by oxidation of the thionophosphate and sulfide groups in each molecule. The analysis of these residues has been simplified and speeded by oxidizing the insecticide and its metabolites to the oxygen analog sulfone with m-chloroperbenzoic acid. After removal of the acid on an alumina column, the compound is determined by GLC with a flame photometric detector. Sensitivity (twice noise) is at least 0.001 ppm. When equal amounts of the six compounds were added to corn, milk, grass, and feces at levels of 0.2 to 5.0 ppm, the recoveries were 95–96% for fenthion and 74–82% for disulfoton and phorate. In analyses of field-treated samples, recoveries were 89–92% of those obtained by previous procedures, which are much more time-consuming.