bluuebunny/crossref_metadata_2025_split huggingface dataset:
Collaborative Study of the Analysis of Acetaminophen in a Sirup and in Combination with Other Drugs in a Tablet
Authors: Hohmann John R 
Published: February 2020

Abstract
Five samples were included in this collaborative study: 2 sirups containing acetaminophen only at 2 levels, 1 commercial tablet containing acetaminophen combined with 4 other drug materials, and 2 synthetic mixtures similar to this tablet, containing acetaminophen at 2 levels. The precision of the analyses of all samples and the accuracy for the 2 sirups and 1 of the tablet mixtures were satisfactory. The recoveries obtained for the second tablet sample were low. In view of the precision for this sample and the accuracy for the others, it is concluded that this sample had been improperly prepared. It is recommended that the method be adopted as official first action.
Rapid Method for the Isolation of Pure Aflatoxins
Authors: Steyn M 
Published: February 2020

Abstract
A chromatographic method is described for the preparation of pure aflatoxins from crude aflatoxin-containing extracts. The stationary phase consists of aluminum oxide (basic, according to Brockman) containing 6.25% oxalic acid dihydrate. The main advantage of this method is that pure samples of individual aflatoxins may be obtained in less than 2 hr. An additional advantage is economy of materials.
Determination of α-Hydroxy Acids in Foods by TLC and Manometric Measurement
Authors: Trop M , Levinger I M 
Published: February 2020

Abstract
An analytical method for determination of α-hydroxy and α-keto acids is developed based on separation of the acids from other components by acidic alcoholic extraction and by adsorption on and elution from an anion exchange resin, followed by thin layer chromatography. Acids are identified by eerie ammonium nitrate reagent sprayed on the chromatogram. Quantitative determination is performed by manometric measurement of gas released in reaction with that reagent.
Improved Colorimetric Method for the Determination of Nitarsone in Feeds
Authors: George G M , Morrison J L 
Published: February 2020

Abstract
An improved procedure for the determination of nitarsone in poultry feeds has been developed. The drug is extracted from feed with 50% dimethylsulfoxide; interferences are removed by column chromatography of the extract on alumina. The drug is eluted from the column with 4% NaOH and assayed colorimetrically with the Bratton-Marshall reaction after reduction of the nitro group with aqueous 4% titanous chloride. The average recovery of nitarsone from laboratory-medicated feed was 97.0% of theoretical with an average coefficient of variation of 3.4%. The method was applicable to both fresh feeds and feeds stored for periods up to 6 months. This method was subjected to a collaborative study for the determination of nitarsone in medicated feeds. The average recovery from 6 collaborators was 103.5% with an average coefficient of variation of 12.7%. Most of the collaborators reported satisfactory results and therefore this method is recommended for adoption as official first action.
Collaborative Study of the Determination of Dimetridazole in Feeds by UV Spectroscopy
Authors: Morrison J L 
Published: February 2020

Abstract
A collaborative study of a previously reported method for the analysis of dimetridazole in feeds has been conducted. The drug is extracted from the feed with methanol, cleaned up by column chromatography on alumina, and measured spectrophotometrically at its ultraviolet wavelength maximum. Nine collaborators participated in this study. The average coefficient of variation was 5.7% for feeds containing 0.015–0.016% dimetridazole and 8.9% for feeds containing 0.05–0.06% dimetridazole. The recovery for these groups was 99 and 97%, respectively. The method is recommended for adoption as official first action.
Collaborative Study on the Determination of Propylene Glycol, Glycerine, and Triethylene Glycol in Tobacco
Authors: Giles J A 
Published: February 2020

Abstract
Propylene glycol, glycerine, and triethylene glycol were extracted from 10.0 g tobacco by shaking 1 hr with methanol. All three polyols were determined simultaneously by GLC of the supernatant extract, using a 42 × 3/16″ column of 1 + 1 Diatoport S-Chromosorb 101 coated with 5% Carbowax 20M-terephthalic acid. The column temperature was programmed at 90−240°C; anethole was used as the internal standard. The method was studied collaboratively by 11 laboratories. Systematic errors have been reduced to acceptable levels except in samples containing very low or high concentrations of a given humectant.
Determination of Cadmium in Total Diet Samples by Anodic Stripping Voltammetry
Authors: Hundley Harvey K , Warren Edward C 
Published: February 2020

Abstract
Anodic stripping analysis was investigated for the determination of cadmium in food samples and was found to be as reliable as atomic absorption for the determinative step. A hanging mercury drop is utilized to form an amalgam during controlled potential reduction. The amalgam is then stripped from the electrode by controlled electrolysis with a linearly varying potential. The recorded current measured during the stripping step was a direct linear function of the bulk concentration of cadmium. The minimum sensitivity, 0.01 ppm or 0.03 μg/ml in the final solution, is limited by the reagent blank.
Gas Chromatographic Determination of Pyrrolidonecarboxylic Acid
Authors: Lee C Y 
Published: February 2020

Abstract
An analytical method is described for analysis of 2-pyrroIidone-5-carboxylic acid (PCA) in foods. PCA was extracted with ethyl acetate, using a modified Widmark extraction apparatus, and then silylated with trimethylchlorosilane and hexamethyldisilazane in the presence of pyridine. The trimethylsilylated PCA derivative was separated by gas-liquid chromatography on a 6′ × 1/4″ °d stainless steel column of 3% SE-30 on Gas Chrom Q and detected with a flame ionization detector. Recovery of PCA was 94-108%. This procedure is a relatively simple and rapid analytical method as compared to the conventional methods.
Rapid Method for Extraction of Light Filth from Corn Meal, Rye, Pumpernickel, and Buckwheat Flour
Authors: Miller Mary T 
Published: February 2020

Abstract
A rapid method for the separation of light filth from a variety of high bran flours consists of a defatting procedure in a Soxhlet extractor, followed by separation of the filth elements with mineral oil in a HCl-ethyl alcohol medium. The proposed method gives clean papers and good recoveries and has no critically timed steps.
Thin Layer Chromatographic Determination of Sodium Monofluoroacetate
Authors: Perry Vernon A 
Published: February 2020

Abstract
A microanalytical method for the detection and quantitative estimation of the rodenticide sodium monofluoracetate from animal tissue has been developed. This procedure uses thin layer chromatography, requires little or no special cleanup, and will detect as little as 0.1 Mg monofluoroacetate as the ammonium salt.
Analytical Methods for the Fungicide ∝,∝-bis(p-Chlorophenyl)-3-Pyridinemethanol
Authors: Day E W , Decker O D , Koons J R , Holzer F J 
Published: February 2020

Abstract
Methods are described for the identification and determination of parinol in formulations, soils, and plant tissues. Gas chromatography on a column of 1.5% OV-17 at 230°C is the most generally applicable technique. Flame ionization detection is employed for macro amounts of parinol and electron affinity for trace quantities. However, an intensely red halochromic salt formed when parinol is dissolved in H2SO4 is the basis for a highly sensitive and selective spectrophotometric procedure. The absorbance maximum at 520 nm obeys Beer’s Law in the 0.5-5.0 μg/ml range. Comparisons of these 2 methods are made for macro quantities of parinol. An alternative residue procedure is suggested which utilizes thin layer chromatography with visualization after H2SO4 spray. Residue data in soils and fruits are reported.
Rapid Qualitative Screening Method for the Detection of Micro Amounts of Cyanide Residues in Wines and Spirits
Authors: Bates Brian L 
Published: February 2020

Abstract
The proposed method for the qualitative screening and detection of prussic acid in wine lees spirits and wines at and below 0.1 ppm is very sensitive and can be performed rapidly using apparatus that is readily available commercially. The method eliminates the concentration step of the modified Hubach method and the test papers can be prepared more quickly and with less manipulation than the FeS04- NaOH test papers of the Hubach method; they are also more sensitive and require no additional color development after removal from the ground-glass flanges as in the Hubach method. The condenser specified for the test is very efficient in preventing alcohol vapors from interfering with the test. A small column of lead dioxide effectively eliminated interference by sulfur dioxide. For samples containing ≥0.1 ppm hydrogen cyanide, as indicated by the intensity of the blue spot, an alternative quantitative method can be used for an accurate assay of the amount present. This test can be applied to other beverages and samples besides wine lees spirits and wines.
Availability Of Iron
Authors: Pla Gwendolyn W , Fritz James C 
Published: February 2020

Abstract
The high incidence of iron deficiency anemia in the United States and elsewhere is caused by insufficient iron intake, plus poor utilization of many dietary sources of iron. There is need to select assimilable sources of iron for fortification of foods; animal studies show that many of the iron compounds used for cereal enrichment are poorly utilized. A method to measure availability of iron is proposed and is currently being studied collaboratively. Preliminary data indicate that in vitro solubility tests are not satisfactory to evaluate availability of iron supplements.
Comparative Analysis of Variance of the Kjeldahl Nitrogen and a Neutron Activation Nitrogen Technique
Authors: Doty W H , Munson A W , Wood D E , Schneider E L 
Published: February 2020

Abstract
A comparative study of the variance components of a neutron activation nitrogen analysis and the Kjeldahl nitrogen analysis was conducted. A total of 448 individual assays were made by each method on 56 samples covering 17 types of feeds and ingredients. The coefficient of variation of the neutron activation data was 1.07. The coefficient of variation of the Kjeldahl data was 0.58. The statistical treatment showed no operator variance in the highly automated neutron activation technique. The total within-laboratory variance was divided evenly between day and error variance in the neutron activation procedure. In the Kjeldahl technique, the greatest portion of the within-laboratory variance was seen in the error (differences/duplicate determination) component.
Effect of Weight Loss of Solvent Extractives During Oven Drying Upon Crude Fat Determinations in Selected Materials
Authors: Gillingham J T , Colby D A 
Published: February 2020

Abstract
Selected stock feeds were analyzed for crude fat by the direct (AOAC 22.033) and the indirect (AOAC 22.034) methods. The direct method invariably yielded lower values (about 2% crude fat), due to instability of solvent extractives at 100°C during drying. The difference between the methods was greatest for silages (about 4.5% crude fat) and it was shown to be due to volatilization of organic acids during drying of the solvent extractive. The authors claim that the indirect method is the better approach to valid crude fat determinations. Vacuum drying (22.003) of oil seeds and silage preparatory to extraction was found to effect a weight loss, exclusive of moisture, either by volatilization or decomposition of heat-labile compounds. Titratable organic acids in silages decreased as a result of vacuum drying. It is claimed that preliminary drying of stock feeds, especially silage, should be accomplished by drying over H2SO4 (22.007) or by freeze-dry ing.
Determination of Water-Insoluble Nitrogen in Mixed Fertilizers
Authors: Katz Stanley E , Fassbender Carol A , Greenstein Merril 
Published: February 2020

Abstract
A procedure was developed for the determination of water-insoluble nitrogen which did not require alteration of the sample by grinding. Samples of the fertilizer were washed in a column with the equivalent of 100 inches of water. The residual nitrogen was then determined by conventional Kjeldahl procedures. The procedure was as reproducible as the present official method but was applicable to all types of sources of water-insoluble nitrogen. Since grinding was eliminated, particle sizesolubility relationships and coatings were not affected.
Evaluation of Methods to Establish the Natural Origin of Adrenal Cortex Injections
Authors: Cunningham C G 
Published: February 2020

Abstract
Usual bioassay methods fail to establish animal origin of the product. Chemical assay and one-dimensional TLC are satisfactory for detecting adulteration when a single steroid (i.e., hydrocortisone) is substituted in an abnormally high ratio to the total steroids. The problem is more difficult when the adulteration is a sophisticated mixture of steroids in their normal ratios. Two-dimensional TLC of the adrenal cortex injection offers the best evidence of adulteration. The presence or absence of nonsteroidic substances naturally present in animal glands is demonstrable in the chromatograms. A standard of identity of adrenal cortex extract is needed to establish the purity and potency of the injection and its natural origin.
Collaborative Study of a Gas Chromatographic Determination of Ethchlorvynol in Drugs
Authors: Davidson Arthur W 
Published: February 2020

Abstract
Ten laboratories studied a GLC method for ethchlorvynol in drugs. l,3-Dichloro-2-propanol is the internal standard and Carbowax 20M is the liquid phase. Recoveries on solutions containing 11.068, 9.000, 46.209, and 54.301 mg/ml were 99.6 ± 2.9%, 100.0 ± 1.3%, 99.7 ± 1.9%, and 100.1 ± 2.9%, respectively. The method is recommended for adoption as official first action.
Methods for Some Alkaloids, Barbiturates, and Combinations. II. Collaborative Study of an Ion Exchange Method for Ephedrine Sulfate or Amphetamine Sulfate Alone or Combined with Barbiturates and Antihistamines
Authors: Smith Donald J 
Published: February 2020

Abstract
Sympathomimetic amines and antihistamines are retained on a column of sulfonated polystyrene cation exchange resin by the positive charge located in the cationic center of the molecule. These basic compounds are eluted from the column with appropriate concentrations of HCl and determined by UV absorption. An anion exchange column assists in removing interfering colored matter. The barbiturates pass through both columns with the original solvent and are measured by UV absorption in a buffered solution. Recoveries for the 8 drug ingredients in 3 combinations range from 98.9±1.7% for ephedrine sulfate to 95.4±3.8% for amphetamine sulfate on 3 practice samples per collaborator, and 99.5±2.0% for ephedrine sulfate to 96.7 ±3.3% for amphetamine sulfate on 6 unknown samples per collaborator. The method is recommended for adoption as official first action.
Spectrophotometric Determination of Phosphatase Activity in Milk Utilizing a New Alkaline Phosphatase Assay System
Authors: Kleyn D H , Yen W 
Published: February 2020

Abstract
The new method is based on the use of phenolphthalein monophosphate as a substrate, for the determination of residual alkaline phosphatase. Upon hydrolysis, phenolphthalein is released to yield a red solution. A visual test, in which the color developed in a milk sample is compared with the color of a standard prepared with the same milk, was collaboratively studied and subsequently adopted as official first action for skim milk, milk, and light cream. In the present study the release of phenolphthalein was quantitated through the utilization of dialysis, followed by subsequent measurement of absorbance of the dialysate in a spectrophotometer at 550 nm or by visual comparison of the dialysate with prepared color standards.
Oxygen Combustion Method for Determination of Bromide Residues in Foods
Authors: Dow Matthew L 
Published: February 2020

Abstract
Samples of wheat, flour, dried milk, or pecans are ashed in a modified Schoniger oxygen flask and bromide is determined by titration with standardized sodium thiosulfate solution or by direct spectrophotometry. A collaborative study indicated about 90% recovery at the 100 ppm bromine level. Standard deviations from 3.7 to 35.3 ppm and from 2.8 to 21.8 ppm were obtained for the titration and spectrophotometric determination, respectively.
Determination of Crotoxyphos in Milk and in the Body Tissues of Cattle and Pigs
Authors: Oehler D D , Claborn H V 
Published: February 2020

Abstract
A new procedure was devised for the extraction, cleanup, and determination of residues of crotoxyphos in milk and in the body tissues of cattle and pigs. The tissue samples were extracted with hexane or hexane-acetone and partitioned into acetonitrile. After cleanup of the extracts and milk on a Florisil column, crotoxyphos was detected with flame photometric gas chromatography. Recoveries ranged from 80 to 98%.
Rapid Sample Preparation for Gas-Liquid Chromatography of Pesticide Residues by Ball-Grinding Extraction, Freeze-out, and Semimicro Column Cleanup
Authors: Grussendorf O W , Mcginnis A J , Solomon J 
Published: February 2020

Abstract
A rapid method for analysis of organochlorine and organophosphate pesticide residues is described. The samples are ground and extracted in one step, using only n-hexane, even for moist materials. Most of the lipids and waxes are removed from the extract by freezeout from acetone solution; pigments and any residual lipids and waxes are removed by a final cleanup on a Florisil column. The semimicro approach is stressed and a number of samples can be processed simultaneously, thus saving time, space, and materials. The procedure is simple, only small volumes of solvent are employed, and good recoveries are obtained. The purity of final extracts is high, thereby avoiding contamination of the GLC column and permitting production of clean, sharp chromatograms. A number of special small, simple metal and glass devices are essential. Specifications for their construction and use are fully described.
Note on Determination of Traces of Silver in Pond Water by Quenching of Fluorescence
Authors: White Merrie N , Lisk Donald J 
Published: February 2020

Abstract
Two new spray reagents for the cholinesterase inhibition method for insecticide analysis are described, namely, the acetate and butyrate esters of N-methyl indoxyl. The fluorescent hydrolysis products have greater fluorescence stability than with indoxyl acetate and are less subject to degradation to nonfluorescent colored substances. Subnanogram amounts of paraoxon were detected on TLC plates.
Note on Improved Spray Reagents for TLC Fluorogenic Detection of Cholinesterase Inhibitors
Authors: Schutzmann R L 
Published: February 2020

Abstract
Two new spray reagents for the cholinesterase inhibition method for insecticide analysis are described, namely, the acetate and butyrate esters of N-methyl indoxyl. The fluorescent hydrolysis products have greater fluorescence stability than with indoxyl acetate and are less subject to degradation to nonfluorescent colored substances. Subnanogram amounts of paraoxon were detected on TLC plates.
Note on a Rapid Determination of Aflatoxins in Peanuts and Peanut Products
Authors: Liem D H , Beljaars P R 
Published: February 2020

Abstract
A simple and rapid extraction procedure, based on a direct extraction introduced by Pons and a single liquid-liquid extraction proposed by Waltking, is described for peanuts and peanut products. Methanol is used as the extracting solvent. TLC, using the system described by Engstrom, yielded satisfactory results. The method is suitable for aflatoxin Bi levels of 8 μg/kg (or higher) in peanut butter and roasted peanut products. Aflatoxin B1 levels down to 3 μg/kg can be detected in raw peanuts and peanut shavings.
Fatty Acid Composition of Cod Liver Oil Determined by Urea Fractionation and Modified Programmed Temperature Gas Chromatography
Authors: Iverson John L 
Published: February 2020

Abstract
Esters of fatty acids in marine oils, with similar GLC retention times, are concentrated in separate fractions by this proposed urea fractionation procedure. Esters which are present at the ppm level and are normally hidden under major peaks can then be detected. By modified programmed temperature gas chromatographic techniques, it is possible to detect trace amounts of the short and long chain fatty acids. Accurate identifications are assured by the correlation of fatty acid structure with the preferential order in which they form complexes and retention times before and after hydrogenation. Cod liver oil was found to contain 130 fatty acids. Most of the esters present in trace amounts are predominately C20 to C34 acids which have not been previously reported.
Sterochemical Composition of d- and l-Amphetamine Mixtures by Thermal Analysis of the Bepzoyl Derivatives
Authors: Ment William M , Marino Victor S 
Published: February 2020

Abstract
A procedure for the thermal analysis of the benzoyl derivative of amphetamine is presented, which enables rapid determination of the stereochemical composition of d- and l-amphetamine mixtures with ±5% accuracy and requires as little as 5 mg amphetamine salt. Identification of the predominant isomer and confirmation of the isomeric ratio estimation are made by the addition to the sample derivative of an equal amount of standard amphetamine benzoyl derivative of opposite isomeric composition in order to form the amphetamine racemate, which is then analyzed by a second melting range measurement. Melting ranges are determined with the aid of a microscope equipped with a Kofler hot stage.
Carbaryl Insecticide: Analysis of Formulations by Colorimetry
Authors: Mcdermott W H , Duvall A H 
Published: February 2020

Abstract
The p-nitrobenzenediazonium fluoborate analytical method for 1-naphthol has been used as a basis of a colorimetric method for determining carbaryl insecticide in formulations. In a solution of KOH in methanol, the carbaryl is saponified to 1-naphthol, which is then determined colorimetrically. This method has been shown to be specific for measuring carbaryl content in mixed formulations in admixture with 13 different pesticides.
Automation of Methods for Meat and Meat Products. I. Determination of Protein
Authors: Mcneal Jon E , Karasz Albert , George Elmer 
Published: February 2020

Abstract
An automated method for the analysis of protein in meat was studied. The investigation included selection of proper standards, development of a method for presolubilizing meat samples for presentation to the AutoAnalyzer, and the construction of AutoAnalyzer manifolds to give protein results comparable to those obtained by the official AOAC Kjeldahl method. The method was found to be applicable to meat and meat products ranging from 5 to 25% protein.
Collaborative Study of Copper, Sodium, and Potassium in Feeds by Atomic Absorption Spectrophotometry and Sodium and Potassium by Flame Emission Spectrophotometry
Authors: Heckman Mary 
Published: February 2020

Abstract
Twelve laboratories collaborated in a study of the analysis of feeds for copper, sodium, and potassium by atomic absorption spectrophotometry and for sodium and potassium by flame emission spectrophotometry. Solutions of feed samples containing known additions of the elements under study were analyzed. Results indicate that the atomic absorption method is suitable for copper. Further study is required for sodium and potassium.