bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gas Chromatographic Determination of Dioxathion and Chlorfenvinphos in Emulsifiable Formulations and Livestock Dips
Authors: Paterson J E 
Published: February 2020

Abstract
A gas chromatographic method is described for the quantitative determination of dioxathion and chlorfenvinphos in emulsifiable concentrates and livestock dips. A convenient quantity of the emulsifiable formulation is dissolved in xylene and the aqueous dip is extracted with xylene for gas chromatographic analysis, using a mixed silicone oil stationary phase and a flame ionization detector. The coefficients of variation for the dioxathion and chlorfenvinphos determinations in the emulsifiable concentrate are 2.4 and 1.0%, respectively. Recoveries of the former from a fouled dip ranged from 97 to 103% and recoveries of the latter ranged from 92 to 97%.
Collaborative Study of Betaine in Orange Juice
Authors: Rogers Grayson R 
Published: February 2020

Abstract
An ion exchange-colorimetric method for determining betaine in orange juice was studied by 11 collaborators on 4 orange juice samples and 2 synthetic water solutions consisting of sucrose, dextrose, and various amino acids found in orange juice. Average recoveries in the collaborative study were 96.7 and 95.9%. Results show that the precision standard deviation among laboratories is generally acceptable. The distribution of the actual data is greater than normally expected, but random errors appear to be responsible since no significant systematic error can be detected in the data. The method is recommended for adoption as official first action.
Levels of Brominated Vegetable Oils in Soft Drinks by X-Ray Fluorescence Spectrometry and Gas-Liquid Chromatography
Authors: Conacher H B S , Meranger J C , Leroux J 
Published: February 2020

Abstract
A rapid screening method using X-ray fluorescence spectrometry has been developed for the detection and semiquantitative estimation of brominated vegetable oils in soft drinks. This method and a quantitative GLC technique have been applied to the determination of the brominated oil content in a wide range of soft drinks. Of 46 drinks examined, 23 contained brominated vegetable oils at levels between 7 and 85 mg/10 fluid oz of drink.
Rapid Colorimetric Assay for Nitroglycerin, Suitable for Content Uniformity Testing
Authors: Wells Clyde E , Miller Harvey M , Pfabe Yvonne H 
Published: February 2020

Abstract
The column chromatographic isolation method of Hohmann and Levine has been combined with a modified version of the colorimetric determination of Bell, resulting in a convenient assay for nitroglycerin in tablets. The method agrees closely with the AOAC infrared method and is sensitive enough for analysis of individual tablets (0.15 mg nitroglycerin). The standard deviation is 0.91% at the 1.2 mg level.
Collaborative Study of the Analysis of Pentaerythritol Tetranitrate and Meprobamate in Tablets
Authors: Hamilton James L 
Published: February 2020

Abstract
Meprobamate and PETN are separated by selective elution from a mixed Celite-sodium hydroxide-phosphoric acid column, using chloroform and benzene, respectively, as eluting solvents. PETN and meprobamate are detected and quantitatively measured by IR spectrophotometry. A collaborative study gave an average recovery of 99.3% for PETN and 99.95% for meprobamate. It is recommended that the method be adopted as official first action.
Comparative Study of Micro Infrared Techniques
Authors: Brannon Wilson L 
Published: February 2020

Abstract
A comparative study was made of several techniques used in the isolation and identification of microgram quantities of drugs by infrared spectroscopy. The isolation techniques include preparative GLC and TLC. In the case of TLC, silica gel interference was nearly eliminated by using a sintered glass filter and vacuum. The identifications were enhanced by concentrating the sample in the infrared beam center. The sample was centered either with the aid of a cardboard silhouette or punched out or drilled indentations in the disk.
Comparison of Separation Procedures for Identification of Oils by Gas Chromatography
Authors: Thorpe Charles W 
Published: February 2020

Abstract
Four methods were evaluated for detecting adulteration of butter fat with vegetable fats. The procedures involve GLC determination of free or combined β-sitosterol after isolation of the sterols by either preparative GLC or digitonin precipitation. Each of the methods was sensitive enough to detect about 1 mg added β-sitosterol/100 g butter fat. Also studied was the free and combined β-sitosterol content of a number of crude and refined vegetable oils. The TLC-GLC method for determining cholesterol in fats and oils, which was collaboratively studied in 1968, is being recommended for official first action status. The GLC portion of this procedure replaces the obsolete one in methods 26.065–26.070 for detecting vegetable fats in butter fat.
Collaborative Study of the Colorimetric Determination of Sulfadimethoxine in Feeds
Authors: Osadca M , De Ritter E 
Published: February 2020

Abstract
A method is described for determination of sulfadimethoxine in medicated poultry feeds. After extraction and purification of the extract, sulfadimethoxine is determined colorimetrically after diazotization and coupling with N-(l-naphthyl)ethylenediamine. The method was studied collaboratively by 11 laboratories on 4 feed samples containing graded drug levels. The method yields good recovery and precision and is recommended for adoption as official first action.
Collaborative Study of the Determination of Tar and Nicotine in Cigarette Smoke
Authors: Ogg C L , Schultz E Fred 
Published: February 2020

Abstract
Ten laboratories participated in a 2-phase collaborative study of a method for tar and nicotine in cigarette smoke. In one phase, 200 monitor cigarettes were smoked, while in the second phase, 60 cigarettes from each of 5 pairs of samples were smoked over a period of 2 weeks according to a random port × sample design. A total of over 9000 measurements was reported for weight, number of puffs, total particulate matter, water, nicotine, and tar. Statistical analysis of the results showed the significant variables to be within- and amonglaboratory differences and a laboratory × material interaction. Agreement between laboratories was good for cigarettes delivering less than 20 mg tar and 1 mg nicotine, but poor for samples with higher tar and nicotine deliveries. Further study of the method is recommended to improve its performance with cigarettes having high tar and nicotine deliveries.
Extraction and GLC Detection of Pentachlorophenol and 2,3,4,6-Tetrachlorophenol in Fats, Oils, and Fatty Acids
Authors: Higginbotham G R , Ress John , Rocke Alan 
Published: February 2020

Abstract
A proposed tentative method for detection of residues of pentachlorophenol and 2,3,4,6-tetrachlorophenol in fats, oils, and commercial food grade fatty acids consists of treating a 5.0 g sample with concentrated sulfuric acid and Celite, followed by a series of liquid-liquid extractions with petroleum ether, aqueous alkali, and chloroform. The residue from the final extract, after further treatment with concentrated sulfuric acid, is analyzed by electron capture GLC. Recoveries of the 2 volatile polychlorophenols were low and varied over a wide range; however, the tentative procedure appears to be satisfactory for qualitative detection at the 0.5 ppm level. Several samples of commercial oleic acids contaminated with chick edema factors were analyzed and were found to be contaminated with pentachlorophenol. Further study of the method is recommended.
Atomic Absorption Spectrophotometric Determination of Boron in Plants
Authors: Melton James R , Hoover William L , Howard Peggy A , Ayers Jo Lynn 
Published: February 2020

Abstract
An atomic absorption method is proposed by which boron can be analyzed in plant materials at concentrations of 3 μg/g o r greater. With the exception of fluorides, no interferences were observed. Results obtained from the proposed method compared favorably with AOAC 6.073. Recoveries of boron ranged from 93 to 107%. This method involves dry ashing the plant sample and treating the ash with 5N HCl. Boron is extracted from this solution into an organic phase of 2-ethyl-l,3-hexanediol in methyl isobutyl ketone. The organic layer is aspirated into the flame without decantation for the determination by atomic absorption.
Note on Solid State Fluorescence Emission of Ochratoxins A and B on Silica Gel
Authors: Chu Fun Sun 
Published: February 2020

Abstract
The fluorescence emission spectra of ochratoxins A and B on silica gel have been determined. The emission maxima for both toxins were found to be around 475 nm, with excitation maxima at 340 nm for ochratoxin A and 325 nm for ochratoxin B.
Collaborative Study of a Method for Cyclohexylamine in Cyclamates and Artificially Sweetened Beverages
Authors: Fazio T , Howard J W 
Published: February 2020

Abstract
A collaborative study was conducted on the method for cyclohexylamine in various artificially sweetened foods and artificial sweeteners published earlier. In this method the amine is isolated by an extraction and/or distillation technique, determined by gas chromatography, and confirmed by infrared spectroscopy. Samples of cyclamates and beverages fortified with cyclohexylamine were analyzed by 7 collaborators. Overall laboratory per cent recoveries for the cyclamates (11 ppm) and beverages (0.5 and 1.0 ppm) ranged from 89.1 to 95.4.
Method for Determining Multiple Residues of Organic Fumigants in Cereal Grains
Authors: Malone Bernadette 
Published: February 2020

Abstract
A method is described for determination of residues of the fumigants methyl bromide, carbon disulfide, chloroform, ethylene dichloride, carbon tetrachloride, and ethylene dibromide in cereal grains. Whole or ground grain is boiled in an acid medium, and the volatile fumigants are dried and collected in cold solvent. Residues are determined by analyzing aliquots of the collected solution by electron capture GLC. Recoveries range from 59 to 105%. Extraction appears to be complete in the 2 hr boiling period specified. An unexplained conversion of carbon tetrachloride to chloroform is described.
New Instrumental Combustion Method for the Microdetermination of Phosphorus
Authors: Handy PAul R , Macdonald Alexander 
Published: February 2020

Abstract
An apparatus has been designed for the determination of microgram quantities of phosphorus-containing compounds. Both inorganic and organic compounds are reduced to phosphine under a stream of hydrogen in a quartz tube at 900-1000°C. The phosphine is separated from other combustion products on sequential alumina and porous polymer bead columns with final measurement by a thermionic GLC detector. The method routinely requires microgram samples with sensitivity capabilities to the nanogram level. The analysis time per sample is less than 5 min.
Note on a Simple Solvent Vent System for the GLC-Flame Photometric Detector
Authors: Watts Randall R 
Published: February 2020

Abstract
A simple solvent vent system is described to prevent extinguishing the flame when 1 μ1 or more of organic solvents is injected into a gas chromatograph with a flame photometric detector. This venting system is simple and inexpensive and also provides a solvent peak for reference in measuring retention times.
Evaluation of Methods for Determination of Moisture in Distillers Process Materials
Authors: Meredith M K , Baldwin S , Andreasen A A 
Published: February 2020

Abstract
Four methods were compared for the determination of moisture in cereal grains and distillers by-product grains: Karl Fischer method, toluene method, vacuum oven method (95–100°C, 5 hr ), and modified vacuum oven method (60°C, 16 hr). The toluene method proved to be the most satisfactory because of its speed and accuracy.
Semiautomated Method for the Determination of Reserpine in Tablets
Authors: Page Donald P 
Published: February 2020

Abstract
A chloroform solution of reserpine tablets is automatically sampled, washed successively with aqueous solutions of citric acid and sodium bicarbonate, and diluted with methanol. The chloroform-methanol solution is split into 3 streams: one flows sequentially through 2 UV spectrophotometers, recording the absorbances at 268 and 295 nm; the other 2 streams are used for the colorimetric assay (addition of hydrochloric acid and sodium nitrite) and blank (hydrochloric acid only). Day-to-day relative standard deviations were 0.40–0.95%. Comparisons with Barkan’s chromatographic procedure and the USP XVII method are presented.
Rapid Fluorometric Method for Determination of Nequinate in Feeds
Authors: Cox Phillip L 
Published: February 2020

Abstract
The modified fluorometric procedure for nequinate in feed eliminates the need for column separation and is well suited for practical routine feed analysis. Nequinate is extracted from feed with 1% formic acid in CHCl3. The extract is filtered and diluted with CHCl3. Methanesulfonic acid is added to enhance the fluorescence of nequinate and the fluorescence is determined at a 270 nm excitation wavelength and a 372 nm emission wavelength. The average recovery of nequinate from feed is 100.5% with a standard deviation of 2.2%. In the presence of most feed additives, the method is quite specific for nequinate. Other 4-hydroxy quinoline coccidiostats presently used as feed additives produce a low level of fluorescence, but qualitative differences can be detected at low concentrations in the presence of methanesulfonic acid due to the lack of a sharp 270 nm excitation peak.
Analysis of Feeds Containing a Combination of Sulfanitran, Aklomide, and Arsanilie Acid
Authors: Morrison J L , George G M 
Published: February 2020

Abstract
Aklomide and sulfanitran can be determined, in the presence of arsanilie acid by removal of arsanilie acid from the methanol extract of t he feed by alumina chromatography. The column effluent is then assayed by the official AOAC colorimetric methods for aklomide and sulfanitran. Arsanilie acid is determined directly on a separate feed sample, using citric acid as the extractant. Recoveries were 94–98% for arsanilie acid, 97% for aklomide, and 95–100% for sulfanitran, with an average coefficient of variation between 3 and 4% for each drug assay.
Atomic Absorption Spectrophotometry of Iron and Aluminum in Baking Powders
Authors: Holak Walter 
Published: February 2020

Abstract
In an atomic absorption method for iron and aluminum in baking powders, organic matter is destroyed with a mixture of H2SO4-30% H2O2, the sample is diluted to within analytical range, and absorption of each element is measured. Concentrations are obtained from calibration curves prepared from standards diluted in the presence of H2SO4 and alarge amount of alkali; the former compensates for the matrix differences and the latter suppresses the ionization of aluminum. Recovery studies with commercially manufactured baking powders to which known amounts of the elements were added indicate that the method is free of interferences for these products. Average recovery and the relative standard deviation for iron and aluminum are 100.4±1.3% and 98.7±1.8%, respectively.
GLC and TLC Determination of Tetraethyl Pyrophosphate (TEPP) in Crops
Authors: Crossley J 
Published: February 2020

Abstract
Two new residue methods have been developed for tetraethyl pyrophosphate (TEPP) on crops. One method employs GLC with thermionic detection and has a limit of detectability of 0.01 ppm. This is the more accurate but less sensitive of the 2 methods. TLC and cholinesterase inhibition is used in the other procedure, giving a limit of detectability of 0.001 ppm. The correlation between the results obtained from the 2 methods is excellent. The method based on GLC was successfully applied to 18 tests on 8 field-treated crops: alfalfa, cabbage, broccoli, green beans (pods and vines), apples, peaches, blueberries, and oranges (peel and pulp). Fortification levels of 0.02 ppm yielded an average recovery in all crops of 85±12%. The TLC method was used to confirm residues found by GLC.
Note on the Extraction of 14C-DDT Residues from Soybeans
Authors: Nash R G , Beall M L 
Published: February 2020

Abstract
Residues of 14C-DDT were not completely removed from fresh or wetted dried soybean plants when hexane-acetone-methanol was used for Soxhlet extraction. The nonextractable 14C presumably was contained in degraded residues of DDT.
Comparison of Gas-Liquid Chromatographic and Chemical Methods For Quantitative Determination of the Menadione and Menadione Sodium Bisulfite Content of Pharmaceutical Products
Authors: Sheppard A J , Hubbard W D 
Published: February 2020

Abstract
A collaborative study was conducted to compare the NF XII method and a GLC method for quantitatively determining menadione in pharmaceutical products. Ten collaborating laboratories analyzed 6 Pharmaceuticals encompassing tablets, capsules, and a liquid. Menadione is extracted with diethyl ether from ground tablets; slip capsules are opened and the contents are emptied into the ether along with the capsule parts. After filtration and removal of the ether, the residue is redissolved in n-hexane. The menadione sodium bisulfite injectable is transferred to a separatory funnel and extracted with chloroform and sodium hydroxide, evaporated to dryness, and redissolved in n-hexane. Menadione is chromatographed on a 6’ × 3mm id glass column packed with 1% neopentyl glycol succinate on 100–120 mesh Gas Chrom Q and operated at 135°C. The carrier gas flow is adjusted so that menadione appears within 5.5–6.5 mhi. Because of the coefficients of variation, additional study is recommended.
GLC Determination of Nikethamide in Injections
Authors: Newton John M 
Published: February 2020

Abstract
A GLC method for the direct determination of nikethamide in injections uses a KC1 thermionic detector which is sensitive to nitrogencontaining compounds. As little as 1 ng nikethamide is detected. The proposed method was compared to the NF XII method on various commercially prepared samples; the results are in good agreement.
Study of the AOAC Chromatographic Procedure for Reserpine Tablets
Authors: Dow Matthew L , Grant Raymond C 
Published: February 2020

Abstract
The procedure developed by Barkan and Kunze was used to analyze uncoated reserpine tablets representing 108 formulations from 60 drug manufacturers. To assay certain products, changes in the original method were required because of interferences from excipients; these changes involved column and sample preparation. The standard deviations of the modified procedure were 1.54% of declared (ultraviolet assay) and 0.90% of declared (colorimetric assay) at the 0.25 mg/tablet level.
Effect of Formaldehyde on the Crude Fat Content of Ground and Diced Beef
Authors: Benson John H , Coleman Charles H , Sarnow Norbert P 
Published: February 2020

Abstract
Ground and diced meat, with and without added 0.5 ml formaldehyde/Lb, was tested for the effect of the preservative on the analysis for crude fat. Twenty-two collaborators each analyzed 4 samples. Statistical analysis of the results indicates that there is no difference in the Soxhlet fat analysis for preserved and unpreserved meat.
Bleaching and Staining Procedure for Microscopic Counting of Insect Fragments and Rodent Hairs in Ground Cocoa Bean Products
Authors: Brickey Paris M , Gecan John S 
Published: February 2020

Abstract
Ground cocoa bean tissue is decolorized with hydrogen peroxide, then stained with picric acid to make decolorized hairs visible. Hydrogen peroxide does not destroy rodent hairs or decolorize insect fragments as does sodium hypochlorite which has previously been recommended by several researchers as a plant bleaching agent.
Sensitive Microbial Assay Procedure for Chlortetracycline in Milk and Related Products
Authors: Katz Stanley E , Fassbender Carol A 
Published: February 2020

Abstract
A microbiological assay procedure with increased sensitivity was developed for milk and some of its products. The procedure is based on the classical cylinder-plate assay procedures with the following modifications: closer adherence to a consistent pH of 4.5, centrifugation of samples to remove the physical barriers to diffusion of the antibiotic, and use of a thin, single layer of seeded agar. Recoveries in milk by this procedure averaged 65.3% versus 37.9% for those obtained using FDA methods. Improvements in recoveries were noted with the milk products studied. Of the chlortetracycline added to milk, 25% was converted to the epimer form which has negligible microbiological inhibitory properties. Binding and/or the inability to account for the antibiotic was found to be negligible.
Gas-Liquid Chromatographic Column Preparation for Adsorptive Compounds
Authors: Ives N Fred , Giuffrida Laura 
Published: February 2020

Abstract
Adsorption is a major difficulty in the gasliquid chromatography of low nanogram quantities of certain organic compounds. Investigations were conducted to identify and remedy problem areas. Column support material was the greatest factor contributing to adsorption problems. Column preparation procedures are described which substantially decrease detrimental column effects.
Gas-Liquid Chromatographic Determination of Saccharin in Soft Drinks
Authors: Conacher H B S , O’Brien R C 
Published: February 2020

Abstract
A quantitative GLC technique has been developed and applied to the determination of saccharin in several dietetic soft drinks. The procedure involves conversion of saccharin by diazomethane to the N-methyl derivative, which is determined by GLC, using methyl stearate as internal standard. Recoveries of known amounts of saccharin added to a drink ranged between 96.0 and 102.0%. The saccharin content of the commercial drinks analyzed ranged from approximately 30 to 90 mg/10 fluid oz.
Survey of Cyclohexylamine Content of Food Products Containing Cyclamates
Authors: Fazio T , Howard J W , Haenni E O 
Published: February 2020

Abstract
A national survey was conducted to ascertain the relationship of the cyclohexylamine content of cyclamate-containing products to their composition, processing, and storage conditions. Cyclohexylamine was found in 174 of the 232 samples examined. The cyclohexylamine content range for each major type of food product was as follows: 0.0–8.2 ppm for carbonated beverages; 0.0–5.8 ppm for dry beverage bases; 0.0–1.5 ppm for fruit juices; 0.0–0.8 ppm for weight control foods; and 0.3–66 ppm for food sweetener preparations (liquid and dry base). No correlation between the cyclamate content of products and the cyclohexylamine present was evident. However, the findings indicate that significant hydrolysis of cyclamate can occur.
The Neutron Activation Analysis Program of the Food and Drug Administration
Authors: Tanner James T , Lambert J P F , Simpson R E 
Published: February 2020

Abstract
Activation analysis is a rapid and sensitive method of trace element analysis applicable to a large variety of samples. For the most part the method is nondestructive; however, for highest sensitivity, chemical separations are usually required. For about 4 years the Food and Drug Administration, utilizing the Naval Research Laboratory reactor, has applied neutron activation to various samples of foods, drugs, and biological materials. Elements such as vanadium, selenium, and mercury have been determined at the nanogram level with little interference from the matrix. Possibly more important than interest in specific element determinations themselves is utilization of the elements or element profiles as indices of required information. Thus, in several forensic applications the authenticity of drugs and food items has been evaluated through the characteristic gamma-ray spectral ”signatures.” Through neutron activation the distribution of mycotoxin contamination in batches of foodstuffs has been simulated to establish homogeneity of sample preparations. This paper presents some earlier examples of the applications of neutron activation analysis which have been made in FDA and summarizes recent work.