bluuebunny/crossref_metadata_2025 huggingface dataset:
Collaborative Study of the Quantitative Gas-Liquid Chromatographic Determination of Fusel Oil and Other Components in Whisky
Authors: Kahn J H , Blessinger E T
Published: February 2020

Fifteen chemists participated in a collaborative study for the quantitative pas-liquid chromatographic determination of the individual fusel alcohols and ethyl acetate in whisky. Two levels of congeners represented by 4 coded samples of whisky were analyzed by using t h e proposed method, employing a glycerol-1,2,6-hexanetriol column, and the official AOAC method, 9.063-9.065. Since isobutyl and the atnyl alcohols comprise by far the greatest part of fusel oil, their determination is of major importance to the total fusel oil content . Statistical analyses show that the proposed method is superior to the AOAC method for the determination of these alcohols, whereas the official method is superior for the determination of ethyl acetate and n-propyl alcohol. In general, collaborators employing modern instrumentation preferred the proposed method over the AOAC method. The former method also separates and permits the quantitative measurement of active amyl and isoamyl alcohols. The proposed method has been adopted as official first action as an alternative to 9.063–9.065 for the determination of higher alcohols and ethyl acetate in whisky.
Collaborative Study of a Gas-Liquid Chromatographic Method for the Determination of Methanol in Alcoholic Beverages
Authors: Dyer R H
Published: February 2020

A collaborative study to determine methanol in alcoholic beverages, using the gas-liquid chromatographic conditions described in the AOAC method for the determination of higher alcohols, 9.063, was carried out. The results showed good recovery values for spiked samples and acceptable standard deviation values, and, according to the ranking test, all collaborators were within the allowable score limits . The advantage of using this chromatographic system for methanol is discussed. The method has been adopted as official first action for the determination of methanol in alcoholic beverages asan alternative to 9.071–9.074.
Efficacy of Various Organic Solvents for the Rapid Direct Determination of Moisture in Meat and Meat Products
Authors: Cohen Edward H , Kimmelman Charles P
Published: February 2020

Twenty-seven organic solvents that form azeotropes with water were tested for use in shortening the time required for the determination of moisture in ground meat, processed frankfurters, and uncooked pork sausage mixture. A goal of 15–30 min was sought with a minimum of 95% recovery of the available moisture content in the meats by use of inexpensive “in stock” available equipment that could be used by nontechnical personnel. Azeotropic distillation in a modified 10 ml Bidwell-Sterling moisture receiver, West condenser, 40/50 boiling flask, and matching enclosed heating mantle was used for periods of time up to 30 min. For example, in 2 lots of ground meat after a 30 min distillation time, the following average recoveries (%) were found: toluene 95, octane 97, nonane 100, xylene 99.7, ethylbenzene 99.4, cumene 100.3, 2-ethyl-1-hexanol 97.7, 1-heptanol 99.5, 1-octanol 99.8, 2-octanol 100.1, and butyl ether 98.5. The latter 9 solvents were found to give acceptable recoveries in 15 min. Chlorinated hydrocarbons were also evaluated but are not recommended due to toxicity levels and the need for specialized equipment.
Rapid Semimicro Method for the Determination of Methyl Mercury in Fish Tissue
Authors: Uthe J F , Solomon J , Grift B
Published: February 2020

A fast semimicro method for the determination of methyl mercury in fish tissue is described. The procedure involves extracting the methyl mercury into toluene as methyl mercuric bromide, partitioning the bromide into aqueous ethanol as a thiosulfate complex, and re-extracting into benzene as methyl mercuric iodide. Methyl mercury is quantitated with gas chromatography. The method is sensitive to 0.01 ppm. Recoveries of added methyl mercury were 99% and the presence of methyl mercury in the final extract was shown by thin layer chromatography and gas chromatography of the thin layer spot. A variety of mercurial compounds do not interfere in the analyses. The amounts of both methyl and total mercury found in a variety of tissues of aquatic animals are compared. The presence of a demethylase in seal is suggested by the findings of high levels of nonmethyl mercury. Additional cleanup by column chromatography on Florisil was necessary with certain samples. The gas chromatographic columns were kept operational by the intermittent injection of 3M potassium iodide. Due to column bleed and resulting detector contamination, the use of the easily cleaned concentric tube electron capture detector is recommended.
Gas Chromatographic Determination of Phenolic Compounds in Drug Preparations: Collaborative Study
Authors: Douglas Carol C
Published: February 2020

A gas chromatographic method for the determination of phenol, methyl salicylate, menthol , and camphor in drug preparations was studied collaboratively by 9 laboratories. Mean recoveries were: phenol 98.2, 106.0, a n d 103.6%; methyl salicylate 103.9, 102.0, and 101.9%; menthol 102.9 and 100.9%; and camphor 101.9 and 100.9%. The method has been adopted as official first action for camphor-containing drugs. Additional study will be done to improve recoveries for the other 3 compounds.
Concentration and Estimation of 14 Polycyclic Aromatic Hydrocarbons at Low Levels in High-Protein Foods, Oils, and Fats
Authors: Grimmer Gernot , Hildebrandt Armin
Published: February 2020

Fourteen polycyclic hydrocarbons in (I) meat, poultry, fish, and yeast, and (II) fats and oils have been isolated and determined. To separate group I homogeneously, 2N methanolic KOH is used. In the first step of concentration (methanol-water-cyclohexane partition (4 + 1 + 5)), a 200 g sample is reduced to 0.2 g of polycyclic fraction without any emulsions. The same effective concentration is found for group II without a saponification step by partition in N,N-dimethylformamide-water-cyelohexane (9 + 1 + 10). Further very effective concentration (100:1) of polycyclics results from filtration on Sephadex LH 20 (solvent:sopropanol). After further cleanup by filtration on silica gel (Woelm, 15% water), phenanthrene, anthracene, pyrene, fluoranthene, chrysene, benzo(a)anthracene, benzo(a)pyrene, benzo-(e)pyrene, benzo(k)fluoranthene, perylene, anthanthrene, benzo(g,h,i)perylene, dibenz(a,h)-anthracene, and coronene are separated on an aluminum oxide column (Woelm, 5.4% water) or equivalent. Recoveries ranged from 75 to 92% for all polycyclics down to the 2 ppb level.
Determination of Bismuth in Body Tissues and Fluids After Administration of Controlled Doses
Authors: Hall Robert J , Farber Theodore
Published: February 2020

Controlled amounts of water-soluble and water-insoluble bismuth salts were administered to dogs. Body tissues and fluids were examined for resultant bismuth residues by an acid digestion-atomic absorption procedure. The method was shown to recover bismuth added to body tissues and fluids; the acid digestion released the bismuth residues almost completely. the highest levels of bismuth were found in the kidneys: about 10 ppm bismuth resulted from the administration of the waterinsoluble compound, bismuth subcarbonale, and about 60 ppm from the soluble compound, bismuth ammonium citrate . The levels of bismuth found in the urine were higher than those found in the other body tissues and the blood serum, but were still relatively low. No pathological manifestations were observed after short-term exposure to bismuth.
Gas Chromatographic Determination of Terrachlor in Fertilizers
Authors: Hanks Alan R , Engdahl Barbara S
Published: February 2020

A simple and rapid method is desorihed for the determination of terraehlor in fertilizers. Terrachlor is extracted with chloroform, and aldrin is added as an internal standard. The extract is injected into a gas chromatography and peak height ratios are used for quantitative measurement. Analysis of commercial samples gives good precision while analysis of prepared samples gives recoveries ranging from 99.3 to 100.4%.
Determination of Lead in Fish by Atomic Absorption Spectrophotometry and by Polarography. II. Collaborative Study
Authors: Gajan Raymond J , Larry Damon
Published: February 2020

Nineteen laboratories, using 6 different models of atomic absorption spectrophotometers and 4 different types of polarographs, participated in this collaborative study. The average lead recoveries from 6 paired samples at 1–2, 5–6, and 10–11 ppm levels were 97.7% by polarography and 100.7% by atomic absorption. The average standard deviations were 0.32 and 0.41 ppm, respectively, and the average coefficients of variation were 7.9 and 13.1%, respectively. With collaborators reporting on both methods, the results of the overall method average were 4.3 ppm for polarography and 4.4 ppm for atomic absorption. Since there were no significant differences (p > 0.05) found between the method averages, except at one of the unspiked levels, the 2 methods can be used to confirm each other at levels of 1-11 ppm. The polarographic method has been adopted as official first action for the determination of lead in fish.
Improved Extraction Procedure for Dimetridazole as Applied to Assay of Samples of Animal Origin
Authors: Allen Patricia C
Published: February 2020

A method for extraction of dimetridazole is described which affords high percentage recoveries of the drug from samples of animal origin. Samples are homogenized with benzene in the presence of just enough aqueous base to insure conversion of all the drug to the free base form and yet obtain a single phase liquid extract. Polarographic analyses of samples spiked with 267 and 33.3 ppm drug showed average recoveries, respectively, of 88.2% (range, 70.5–99.2%) and 87.8% (range, 78.6–101%). The average coefficient of variation for detection of these levels of drug was 3.33%. Under assay conditions, 1 ppm dimetridazole in tissues could not be detected. Factors affecting extent of drug extraction are discussed.
Identities of Polychlorinated Biphenyl Isomers in Aroclors
Authors: Webb Ronald G , Mccall Ann C
Published: February 2020

Twenty-seven PCB isomers in Aroclors 1221, 1242, and 1254 were separated and identified by matching both their GLC retention times and infrared spectra with known compounds prepared by the Gomberg or Ullmann reactions. The retention times of the PCB are presented relative to p,ṕ-DDE.
Liquid Chromatography of Polycyclic Aromatic Hydrocarbons
Authors: Ives N Fred , Giuffrida L
Published: February 2020

The liquid chromatography of 18 polycyclic aromatic hydrocarbons was investigated by using a continuous monitoring ultraviolet detection system. Two column materials, Durapak OPN and 40% cellulose acetate, were compared for orders of elution and resolution. Neither system resolves all the compounds tested but the use of more than one system increases the number which may be resolved. This investigation demonstrates the potential of analytical liquid chromatography for the resolution and analysis of such compounds.
Detection of Hexachlorobenzene Residues in Dairy Products, Meat Fat, and Eggs
Authors: Smyth Robert J
Published: February 2020

A rapid, one column chromatographic method using deactivated Florisil for the cleanup of fatty foods is described. Hexachlorobenzene which is only partially recovered by multiple residue methods is recovered in excess of 80%, using the method described. A gas chromatographic column containing a mixture of DC- 200 and QF-1 as stationary phase for the separation of hexachlorobenzene from a-benzene hexachloride is also described.
Thin Layer Chromatographic Detection of Chlorinated Hydrocarbons as Cross-Contaminants in Pesticide Formulations
Authors: Bontoyan W R , Jung P D
Published: February 2020

Chlorinated pesticide contamination studies are reported in which a TLC method is used to analyze a variety of dust and liquid formulat ions. Eight g samples are extracted with 20 ml acetone, followed by elution with n-hexane on silver nitrate-aluminum oxide G TLC plates. This paper reports the results of a 4 year study, using a large collaborative sampling, in which the detection limits and utility of the described procedure were examined. The method has been adopted as official first action for the detection of co ntamination by 0.01% aldrin, dieldrin, endrin, and technical DDT and by 0.05-0.10% chlordane, Strobane, and toxaphene.
The Prosecutor and the Forensic Scientist
Authors: Gunn John W , Flannery Thomas A
Published: February 2020

In recent years, the role of the forensic scientist has become a matter of critical importance in filling the evidence void created by decisions of the U.S. Supreme Court. This role is reviewed from the viewpoint of the prosecutor, since it is in court, as an expert witness, that the forensic scientist must prove his worth. Those areas which are considered vitally important, such as adequate preparation and courtroom demeanor, are discussed. The criminal justice system must make full use of advanced scientific methods in the courtroom. The need for more dialogue between the forensic scientist and the prosecutor to develop criteria on when and how to introduce these methods is reviewed.
The Use of NMR and Mass Spectral Data in the Forensic Laboratory
Authors: Sobol Stanley P , Barron Robert P , Kram Theodore C
Published: February 2020

The role of the forensic laboratory in law enforcement is briefly discussed. Not only is it necessary to identify the major constituent of an exhibit, but in many cases valuable intelligence is gained by identifying whatever else is present. This includes other drugs, excipieuts, metals, etc. Therefore, identification of an extremely wide range of chemicals is required. The use of NMR and mass spectral data in the positive identification of such substances is invaluable. Specific examples of these data in identification are discussed.
Collaborative Study of the Determination of Boric Acid in Foods by Atomic Absorption Spectrophotometry
Authors: Holak Walter
Published: February 2020

Caviar and dried apricots containing a known amount of added boric acid were subjected to a collaborative study. The samples were digested with sulfuric-nitric acid under reflux; the boron was then complexed with 2-ethyl-1,3-hexanediol and extracted into methyl isobutyl ketone. Boron in the organic phase was determined by atomic absorption, using a nitrous oxide-acetylene flame. The recoveries were satisfactory: 103, 95, and 93% for 300, 1000, and 1600 μg boron/g apricots and 95, 90, and 92% for the corresponding caviar samples. The method has been adopted as official first action.
Toxic Effects of the Mycotoxins Aflatoxin B1, Rubratoxin B, Patulin, and Diacetoxyscirpenol on the Crustacean Cyclops fuscus
Authors: Reiss Jürgen
Published: February 2020

The effect of various concentrations of the mycotoxins aflatoxin B1, rubratoxin B, patulin, and diacetoxyscirpenol on the crustacean Cyclops fuscus was studied. Aflatoxin B1 was most toxic, followed by diacetoxyscirpenol and rubratoxin B. Patulin showed toxicity only at the highest level (100 μg/ml).
Infrared Studies of Cyclohexylamine
Authors: Chen Jo-Yun T , Gould John H
Published: February 2020

The IR spectral data suggest strongly that cyclohexylamine exists as 2 conformers in dynamic equilibrium: an equatorial and an axial form. In the liquid state, under standard conditions, these 2 conformers appear to be present in about equal amounts, but the equilibrium shifts with changes in the physical state of the compound. In the vapor state, the equatorial form is predominant, while in the crystalline solid state at temperatures below – 6°C, only the axial form was observed. This study also shows that the equatorial form is converted to the axial when the sample is subjected to high pressure. The marked chemical reactivity of cyclohexylamine results in its forming a coordinate complex with silver chloride and ammonium salts with CO2 and CS2, all spontaneously at room temperature. The IR spectra of these derivatives of cyclohexylamine are discussed.
Quantitative Determination of Cadmium in Water-Soluble Color Additives by Atomic Absorption Spectroscopy
Authors: Moten Lueangier
Published: February 2020

A quantitative method is presented for the determination of cadmium at low levels (5–20 ppm) in water-soluble color additives by atomic absorption spectroscopy. Absorption measurements were made on aqueous solutions of typical color additives to which known amounts of cadmium had been added. The method requires no pretreatment of sample and should be applicable to all water-soluble color additives.
Gas-Liquid Chromatographic Determination of d-trans-Allethrin
Authors: Meinen Vernon J
Published: February 2020

A gas chromatographic method is described for the quantitative determination of d-trans-allethrin in the technical product and in various formulations. The samples are diluted with acetone and analyzed by gas chromatography, using a flame ionization detector and a column packed with OV-1 on Chromosorb W (HP). Preliminary work indicates that satisfactory results can be obtained with the technical material and several different formulations. Since this method is more rapid and specific than the present AOAC titrimetric method, it is expected that it will be a valuable supplement to or alternative for the AOAC method for the analysis of allethrin.
Infrared Analysis of Pesticide Formulations
Authors: Goza S W
Published: February 2020

The Virginia Department of Agriculture and Commerce Pesticide Formulation Laboratory has compiled infrared methods for 60 pesticides, which are distributed to other laboratories. Four basic procedures are used and standardized volumes and aliquots, when possible, are specified to simplify sample preparation. One of the standardized procedures is described in detail.
Nonaqueous Copper Colorimetric Method for Determination of Malathion in Technical Grade Malathion and in Malathion Formulations
Authors: Wayne R S , Ghoth W C , Miles James W , Guerrant Gordon O
Published: February 2020

A nonaqueous copper colorimetric procedure has been developed for the assay of technical and formulated products of malathion. The stability of the copper O,O-dimethyl phosphorodithioate complex has been substantially improved by the use of nonpolar solvents and by lowering the hydrogen ion activity of the system. This has permitted the elimination of the partitioning step and has relaxed the critical timing requirements specified in the offi cial first action AOAC method. The new method has a precision of ±1.6% at a 95% confidence level. The accuracy of the technique is discussed in terms of various minor interferences and by contrasting the results obtained with alternative assay methods.
AG Chlordane: Development of Methods for Its Analysis and Control
Authors: Malina M , Rozek A , Schwemmer B
Published: February 2020

AG chlordane is a high purity compound containing 95% α- and γ-chlordane. Five methods have been developed for analyzing AG chlordane and its formulations. Two methods involve infrared procedures: assay of AG chlordane in granular formulations and α- and γ-chlordane in AG chlordane. The other 3 methods used gas chromatography as the determinative step: assay of heptachlor and nonachlor in AG chlordane and AG chlordane in emulsifiable concentrates. The precisions obtained for all 5 methods are good.
Atomic Absorption Determination of Total, Inorganic, and Organic Mercury in Blood
Authors: Magos Laszlo , Clarkson Thomas W
Published: February 2020

The atomic absorption method described will determine total mercury and, selectively, inorganic mercury. Organic mercury is measured as the difference between total and inorganic mercury. Lower levels of mercury in samples of human blood (4.1 ng Hg/ml) can be determined with the following precision: total mercury 0.6%, inorganic mercury 8.7%, and organic mercury 5.6%. The mean deviation of 2 sets of analyses, one carried out with the method described in this paper and the other with neutron activation analysis, was 3.6%. Organic (presumably methyl) mercury accounted for 66% of the total mercury in blood in a population with minimum exposure. The red cell-to-plasma ratio of organic (methyl) mercury averaged 13.9 in a population with moderate exposure to mercury in food.
Comparison of Two Extraction Procedures for the Determination of Cholesterol in Dairy Products
Authors: Lacroix Denis E , Feeley Ruth M , Wong Noble P , Alford John A
Published: February 2020

Both the Roese-Gottlieb and silicic acid methods have been used for the extraction of lipids from dairy products. However, the silicic acid method is widely used for the extraction of fatty acids for determination by gas-liquid chromatography. Since it would be advantageous to use this extract for cholesterol determinations, a comparison of the extraction procedures for dairy products was carried out to determine if they gave equivalent values. Cholesterol values were determined by gasliquid chromatography of both extracts. Twenty samples of 6 dairy foods having a milkfat content ranging from 3 to 38% were compared. In every instance the Roese-Gottlieb extracts had higher values for cholesterol than did those from the silicic acid method. With very low fat products the Roese-Gottlieb value was high in 6 of 8 comparisons, but the range among samples was much greater. The Roese-Gottlieb or similar multiple solvent extract methods should be used for all dairy products and any other food product in which part of the cholesterol may be bound to a lipoprotein or otherwise not free in the fat.
Collaborative Study of the Official AOAC Flame Photometric Method for the Determination of Sodium in Fertilizers
Authors: Corominas Luis F
Published: February 2020

The present official final action method, 2.132–2.135 (11 th Ed.), has been compared with the 10th Edition method, 2.117–2.120; the need for ion exchange cleanup before flame photometry was also studied for samples containing 0.1-0.7% sodium. In general, the 11th Edition method produced more precise results; elimination of ion exchange treatment improved values obtained for the standard deviations of the systematic error. These findings are based on 600 individual results reported by 9 laboratories for 4 samples.
Collaborative Study of the Determination of Molybdenum in Fertilizers
Authors: Koirtyohann S R
Published: February 2020

An atomic absorption method for the determination of molybdenum in fertilizers was tested collaboratively. The results indicate that additional work is needed to improve precision at low molybdenum levels and to test for a possible positive bias in the method.
Collaborative Study of Analytical Methods for Fluoride in Vegetation: Effects of Individual Techniques on Results
Authors: Jacobson Jay S , Mccune D C
Published: February 2020

A collaborative test of analytical methods and techniques for fluoride in samples of vegetation was carried out by 64 participants and effects on the magnitude and variability of analytical results were assessed. Betweenlaboratory precision (standard deviation) for all data ranged from 2.7 ppm F for the 4 ppm sample to 53 ppm for the 365 ppm sample. Relative standard deviations ranged from 14 to 23% for the samples containing more than 27 ppm F. When data were grouped according to the techniques employed by the collaborators, statistical analyses indicated that many variations in techniques were affecting the analytical results. Both the data and the information supplied by participants support the following conclusions: (1) An explicit set of instructions, specifically designed for samples of vegetation, should be published to reduce the number of variations in analytical procedures used by different laboratories. (2) The semiautomated method, specifically developed for vegetation samples, is a preferred technique because it is simpler and faster than older methods and gives results comparable to those obtained by the Willard-Winter method. (3) The AOAC official final action method for fluoride may be used for the analysis of vegetation if the following modifications are made: Sample size should be 2–10 g dry weight; nickel, Inconel, or platinum crucibles should be used for ashing; 5 g sodium or potassium hydroxide should be used for fusion of ash at 600 °C; and 500 ml distillate should be collected. Results of this collaborative study also suggest that additional studies should be performed to discover why alkaline fixative agents used for ashing affect analytical results and whether simpler and more precise analyses will be obtained by replacing titrimetric or spectrophotometric techniques with the use of the selective ion electrode.
Analysis of Drugs in Pharmaceuticals, Using Simple Extractions and Semiautomated Gas-Liquid Chromatography
Authors: Fricke Fred L
Published: February 2020

A gas-liquid chromatographic method is presented for several drugs, using Dexsil 300 as the liquid phase and an automatic sample injector. Results by this method and the official or other applicable methods are compared. It is demonstrated that content uniformity analyses can be made by using this procedure. The extractions and chromatographic conditions have been standardized to make possible a successful interlaboratory study.
Effect of Maleic Acid on the Ultraviolet Absorption of Some Antihistamine Maleate Salts
Authors: Hamilton James L , Naviasky Helen S , Ment William M
Published: February 2020

Several official compendial monographs contain assay procedures which compare the ultraviolet (UV) absorbance of a sample solution of a mineral acid salt of an antihistamine with that of a standard solution of the antihistamine maleate salt. The recovery data, UV absorbance values, and UV spectra presented show that erroneously low assay results are obtained when UV absorptions (below 280 nm) of antihistamine maleate sample solutions previously extracted from alkaline aqueous media into organic solvents are compared with antihistamine maleate standard sample solutions diluted directly in the same acid medium. Such errors are shown to be caused by the UV absorption properties of the maleic acid moiety.
Analysis of Myo-inositol in Dry Beans by Gas Chromatography of Its Hexaacetate
Authors: Seifert Richard M
Published: February 2020

A method has been developed for the analysis of myo-inositol in California small white beans, pinto beans, and 2 pinto bean flake products by gas-liquid chromatography of myo-inositol hexaacetate. The identity of myoinositol hexaacetate from bean samples was confirmed by mass spectrometry and chromatographic retention time. A standard curve prepared by plotting peak height vs. μg myoinositol hexaacetate was linear over the range studied, 0.2 to 0.6 μg. Peak heights were measurable in all samples, although inositol hexaacetate was not completely separated in California small white bean samples. An internal standard, perseitol, was used to correct for losses in the procedure. Hydrolysis of phytin was negligible during sample preparation or analysis. Recoveries of 12 to 40 μg inositol from 40 mg samples of California small white beans averaged 113%. These beans contained an average of 71 ppm inositol compared to 215 ppm inositol in similarly prepared pinto beans.
Colorimetric Determination of Phenylamide Pesticides in Natural Waters
Authors: El-Dib M A , Aly Osama A
Published: February 2020

Phenylamide pesticides include a great variety of compounds such as TV-phenylcarbamates, phenylureas, and anilides. A simple, rapid, and sensitive colorimetric method for their determination in natural waters has been proposed. Phenylamides are rapidly hydrolyzed in acid medium at elevated temperature (150–155°C), yielding the corresponding anilines. The latter compounds are diazotized and coupled with 1-naphthol to yield intensely colored azo dyes. Both phenylamides and aniline derivatives can be determinedined a sample in the presence of each other. The method is sensitive to 0.02 m g/L; coefficients of variation range between 6.0 and 0.2, according to the amount of phenylamide pesticide being measured.
The Determination of Hexachlorophene in Mammalian Tissues by Gas-Liquid Chromatography
Authors: Ulsamer A G
Published: February 2020

Hexachlorophene in mammalian tissues can be determined by extraction with ether-absolute ethanol (18 + 7), formation of the acetyl or methyl derivative, and gas chromatography with a column of 3% OV–101 on Gas-Chrom Q. Recoveries of hexachlorophene added to blood ranged from 86% at 0.005 μg/ml to 97% at 2.0 μg/ml, and for organs from 85 to 97%.
Spectroanalytical Parameters of Fungal Metabolites. III. Ochratoxin A1
Authors: Neely W C , West A D
Published: February 2020

Analytically useful spectroscopic data for k ochratoxin A, previously absent from the literature, are presented. The value of the extinction coefficient of the analytically preferable 333 nm absorption band in absolute ethanol was determined to be 4680±40 over the range , 1.9 × 10±6-4.8 × 10±4M. The possibility of ionization upon dilution is discussed. Ochratoxin A exhibits fluorescence and phosphorescence of approximately equal intensities. The lifetimes of these are 3.2 × 10±8 sec and 0.28 sec, respectively. Some photodecomposition occurred under prolonged light exposure.
Rapid Method for Analyzing Resmethrin Content in Formulations and Determining the cis-trans Ratios
Authors: Heath Robert R
Published: February 2020

Total resmethrin was determined in test formulations prepared in petroleum distillates and in micronized dust formulations by gasliquid chromatography. The ratio of the 2 geometrical isomers was obtained from the nuclear magnetic resonance spectrum of the parent acid after hydrolysis of resmethrin. This method of determining isomer ratios was faster and somewhat more accurate than the infrared method.
Gas Chromatographic Determination of Phosphamidon Insecticide in Formulations
Authors: Carlstrom A A
Published: February 2020

The GLC method described is specific for measuring 4 components of Phosphamidon Insecticide—deschlorophosphamidon, α-phosphamidon, β-phosphamidon, and γ-chlorophosphamidon. The sample is extracted with acetone, an internal standard (dicyclohexyl phthalate) is added, and the solution is diluted to volume and injected into a gas chromatograph equipped with a flame ionization detector. Although the GLC peak areas for phosphamidon are not linear over a wide range of concentration, good results are obtained when sample and standard concentrations are matched to within 10%. A 1.21% coefficient of variation was found for 19 repetitive injections.
Quantitative Determination and Confirmation of Low Levels of Diethylstilbestrol in Feeds
Authors: Jeffus Marshall T , Kenner Charles T
Published: February 2020

A method for the determination of diethylstibestrol in feeds, which is based on official first action method 38.048–38.051, is proposed. Interfering feed extractives are removed by using a tripotassium phosphate-Celite column prior to measurement at 415 nm before and after irradiation. Recoveries of equilibrated standards added to Soxhlet extracts of several samples averaged 94.3% compared to 86.3% by the official method. The background absorbance at 415 nm obtained by using the proposed method was approximately 6% of the background by the official method for solutions containing equivalent amounts of sample. A thin layer chromatographic method is also included for the confirmation and identification of the cis and trans isomers of the drug. The proposed method has been found satisfactory for the quantitative determination of 0.55–44 ppm diethylstilbestrol and the thin layer chromatographic procedure can detect as little as 0.07 ppm.
Analytical Profile of Scotch Whiskies
Authors: Schoeneman Robert L , Dyer Randolph H
Published: February 2020

In this study, 13 Scotch grain whiskies and 34 Scotch malt whiskies were characterized by both chemical and physical analyses. In addition, 34 blended Scotch whiskies secured in the United States were examined. Official AOAC methods were used to determine the components commonly used in characterizing distilled spirits. In addition, potassium, sodium, copper, zinc, iron, calcium, magnesium, and lead were determined by atomic absorption spectroscopy. Characteristics of the present samples are compared to American whiskies.
Ultraviolet Spectrophotometry of Phenothiazine Derivatives and Analogs
Authors: De Leenheer André
Published: February 2020

Ultraviolet spectral data have been tabulated for 41 phenothiazine derivatives and analogs. The general appearance of the spectra is caused by the structure of the tricyclic π-system, whereas spectral shift effects are produced by R2 substituents. Acceptable correlations were found between the location of absorption maxima and Hammett’s σm and σρ constants of R2 substituents for the phenothiazine derivatives examined.
Determination of Neostigmine Bromide by Ion-Pairing Column Chromatography
Authors: Kling Rita E
Published: February 2020

A rapid and sensitive method for the assay of neostigmine bromide (NBr) in tablets and ophthalmic solutions has been developed. NBr is isolated from its pharmaceutical excipients by the ion-pairing partition column chromatographic principles of Levine and Doyle followed by ultraviolet determination of its alkaline hydrolysis product. Standard recoveries of NBr from simulated tablet mixtures and ophthalmic solutions averaged 99.8%. The standard deviation of repeated analyses of commercial products was less than±1%. The results of the proposed method for commercial products are in good agreement with the USP XVIII procedure. The procedure is applicable to individual tablet assay.
Gas-Liquid Chromatographic Separation of N-Acetyl-n-butyl Esters of Amino Acids
Authors: Vincent Phillip G , Kirksey Jerry
Published: February 2020

Gas-liquid partition chromatography of a number of N-acetyl-n-butyl esters of amino acids has been investigated. Results obtained with a column packed with methyl silicone grease (DC-200, 12,500 est viscosity) were better than those reported for Carbowax 1540 or hydrogenated vegetable oil. Amino acid derivatives were distinctly resolved on methyl silicone grease columns. Preliminary determinations were obtained for synthetic mixtures of the acids. The method should prove a useful adjunct to current techniques for the separation and quantitative measurement of amino acids.
Fluorometric Determination of Oxytetracycline in Premixes
Authors: Katz Stanley E , Fassbender Carol A
Published: February 2020

A simple fluorometric procedure for Oxytetracycline, in which a highly sensitive fluorometer and ultrapure deionized water are used to eliminate background fluorescence, is presented. Recoveries from fortified extracts of commercial premixes ranged from 95.0 to 102.5%; the ratio of results of microbiological to fluorometric methods ranged from 0.97 to 1.05%.
Determination of Crystallinity of α-D-Lactose by Far Infrared Spectroscopy
Authors: Susi Heino , Ard Jesse S
Published: February 2020

The far infrared absorption procedure for the evaluation of crystallinity of α-D-lactose is based on the oil-mull technique and the use of barium carbonate as an internal standard. Fixed slits, ordinate scale expansion, and very slow scanning rates are employed for analysis, and absorbance values are measured by the baseline technique. The method is applicable to samples such as whey solids and other dehydrated dairy products; however, the samples must be uniformly ground before analysis. For 10 test samples, the mean square error is 1.51% and the maximum error is about 2%. The time required for a single analysis is about 1 hr.
Thin Layer Chromatographic-Volumetric Determination of O,O-Dimethyldithiophosphoric Acid and Its Alkaline Salts in Technical Preparations
Authors: Bazzi Brunetto , Fabbrini Riccardo , Radice Marco
Published: February 2020

O,O-Dimethyldithiophosphoric acid and its alkaline salts are separated from impurities in technical preparations by thin layer chromatography on silica gel H, using 2 solvent systems: n-hexane-acetone and isopropanol-ammonium hydroxide. The plate is sprayed with palladium chloride for detection of the compounds. The area is scraped off and the compounds contained in this area are bromometrically titrated for quantitative determination. Good recoveries were obtained for O,O-dimethyldithiophosphoric acid and its sodium and potassium salts in pure samples and technical preparations.
Gamma Spectroscopic Determination of Cesium-137 in Milk, Using Simultaneous Equations: Collaborative Study
Authors: Baratta Edmond J , Knowles F E
Published: February 2020

A gamma spectroscopic method, using a sodium iodide (thallium-activated) crystal, was evaluated by 25 collaborators for the determination of cesium-137 in milk. Overall average recoveries of 295±18.1 and 53±5.3 pCi/L were obtained for samples containing 305 and 52 pCi/L, respectively. These samples also contained iodine-131 and barium-140, which did not interfere with the analyses. The slight bias on the low side and the greater dispersion of results for the low level sample were not considered serious. The method has been adopted as official first action.
Determination of Strontium-90 in Water: Collaborative Study
Authors: Baratta Edmond J , Knowles F E
Published: February 2020

A procedure involving carbonate precipitation and purification with nitric acid was evaluated by 11 collaborators for the determination of strontium-90 in water. The ingrowth level of yttrium-90 is counted and this activity is used to calculate the strontium-90 activity present. The accuracy of the method ranged from 9 to 16% and within-laboratory precision ranged from 13 to 19% for strontium-90 levels of 28.2 to 99.6 pCi/L. A slight bias on the low side, caused by individual laboratory techniques, was not considered serious. The method has been adopted as official first action.
Ion Exchange Determination of Strontium-89 and Strontium-90 in Milk: Collaborative Study
Authors: Baratta Edmond J , Knowles F E
Published: February 2020

A method for the determination of strontium-89 and strontium-90 in milk, involving ion exchange and purification with nitric acid, was evaluated by 11 collaborators. The accuracy of the method for strontium-89 ranged from 2 to 56% and the within-laboratory precision ranged from 11 to 76% for a concentration range of 68–480 pCi/L; values for strontium-90 in a concentration range of 50.2–116.2 pCi/L were 6.4 to 10 and 4 to 11%, respectively. The slight bias on the high side for strontium-90 was not considered serious. The collaborators had difficulty with strontium-89 analyses, as shown by the high precision and accuracy estimation values.
Analysis of Aflatoxins in Sunflower Seeds and Sunflower Meal
Authors: Karmelic Julia , Israel Mery , Benado Sara , Leon Carmen
Published: February 2020

Aflatoxins are extracted from sunflower seeds and meal by chloroform, eluted from a silica gel column, and determined by thin layer chromatography (TLC), using chloroform-acetone-water-2-propanol as the developing solvent. In addition, the TLC step also removes interfering material from some sunflower varieties which is not removed by the cleanup column. Various silica gels were tested for cleanup efficiency. Recoveries of added B1, B2, G1, and G2 were satisfactory.
Thin Layer Chromatographic Detection of Thiabendazole and Benomyl in Fruits
Authors: Tjan Gwan H , Burgers L J
Published: February 2020

Thiabendazole and benomyl are extracted from fruit peels with ethyl acetate and the extracts are filtered. The filtrates are extracted with 0.1N HC1, adjusted to pH 6 with 0.1N NaOH, and re-extracted with ethyl acetate. The concentrated extracts are spotted on plates coated with silica gel GF-254. The fungicides are detected on the plates under shortwave ultraviolet light, after development with chloroform-acetone (8+2), as pink-blue spots on a light fluorescent background. The recovery of thiabendazole from fortified samples is satisfactory, but the recovery of benomyl is not quantitative. For greater specificity, an enzymatic inhibition technique is also described which may be used on the exposed silica gel GF-254 plate or on a silica gel G plate.
Collaborative Study of the Automated Determination of Nitrogen in Meat Products
Authors: Gantenbein Walter M
Published: February 2020

A modification of a previously reported method for nitrogen in meat products was subjected to collaborative study. Samples were dissolved in 1+1 sulfuric acid, cooled to room temperature, and presented to an Auto-Analyzer system. Digestion, dilution, and colorimetric measurement of nitrogen content were performed automatically. Seven collaborators participated in the study, analyzing 8 different samples in duplicate. Results of the study were satisfactory, with an average range of 0.95% protein, average standard deviation of ±0.39, and average coefficient of variation of 2.44%. The method has been found applicable to meat and meat products containing 0.8–4.0% nitrogen (5.0–25.0% protein).
Conditioning of Polyalkyl Glycol Liquid Phases for Flame Photometric Gas Chromatographic Analysis of Dursban and Its Oxygen Analog
Authors: Struble Dean L
Published: February 2020

Dursban and its oxygen analog were resolved by 3 liquid phases, Ucon 75-H-90,000 and Carbowaxes 20M and 20M TPA, on unsilanized, acid-washed Chromosorb W. The GLC responses and resolutions of the 2 compounds were dependent upon the conditioning of the packing before it was placed in the GLC columns. The most satisfactory results were obtained when the column packing was heated in the presence of atmospheric oxygen. The best liquid phase for the GLC analysis of Dursban and its oxygen analog was Ucon 75-H-90,000.
Gas-Liquid Chromatographic Method for the Analysis of Dichlozoline Residues in Grapes and Grape Products
Authors: Pack Donald E , Lee Hwalin , Bouco Léon , Sumida Seizo , Hisada Yoshio , Miyamoto Junshi
Published: February 2020

Dichlozoline residues are extracted from field-treated grapes and the must, juice, or wine derived from them with hexane and analyzed by gas-liquid chromatography, using electron capture detection. For residues below 0.5 ppm, a silica gel G column is used for clean-up. Recoveries of dichlozoline added to grapes at a level of 0.04 ppm and to must, wine, or juice at levels from 0.5 to 1 ppm were excellent. The limit of detection is 0.01 ppm.
Review of the Schoenemann Reaction in Analysis and Detection of Organophosphorus Compounds
Authors: Poziomek Edward J , Crabtree Eleanor V
Published: February 2020

This report reviews the chemistry of the Schoenemann reaction and describes the principles and applications in the detection of organophosphorus compounds. Emphasis is placed on the analysis of the very toxic compounds ethyl N,N,-dimethylphosphoramido cyanidate and isopropyl methylphosphonofluoridate. There are many literature publications and government reports which illustrate applicability of the Schoenemann reaction. Key literature references are mentioned throughout this report; also, there are many citations of unpublished data.
Fluorometric Determination of Decoquinate in Chicken Tissues
Authors: Stone Loyal R
Published: February 2020

Results are reported for a collaborative study of a fluorometric method for decoquinate in chicken tissues in the range 0 to 2.2 ppm. The drug is extracted from tissues by blending with methanol-chloroform. On addition of acid, decoquinate is separated in the chloroform phase and chromatographed on a Florisil column. It is eluted with 1% calcium chloride in methanol and determined by fluorescence measurement. The method has been adopted as official first action.
Volatile Compositional Differences Between Cultivars of Black Pepper (Piper nigrum)
Authors: Russell Gerald F , Else Joanne
Published: February 2020

Computer-generated chromatographic profiles are used to determine whether statistically valid chromatographic differences could be established between Lampong and Sarawak cultivars of Piper nigrum. The solvent is separated on a column of uncoated glass beads; the effluent is then passed through a capillary column coated with SF-96(50). Computer programs were written, and stored data were used to plot simulated chromatograms in a 3-dimensional, topological display where differences were readily discernible.
Gas Chromatographic Determination of Diethylstilbestrol Residues in Animal Tissues
Authors: Coffin David E , Pilon Jean-Claude
Published: February 2020

A procedure is described for the determination of diethylstilbestrol residues in various tissues of beef, chicken, and lamb. This involves acetone extraction of the tissue, HCl hydrolysis, liquid-liquid partition between CHCl3 and aqueous acidic and alkaline solutions, formation of diethylstilbestrol trifluoroacetates, elution of the trifluoroacetates from a Chromosorb W column, and electron capture gas chromatographic detection and measurement of the diethylstilbestrol trifluoroacetates. Recoveries of diethylstilbestrol obtained from a variety of animal tissue samples spiked at 2–10 ppb levels were 70–110%.
Atomic Absorption Spectrophotometric Determination of Aluminum in Pharmaceuticals
Authors: Karkhanis Pramod P , Anfinsen Jon R
Published: February 2020

A simple, sensitive, and rapid atomic absorption spectrophotometric method for aluminum in pharmaceutical preparations is described. No interference from other ingredients has been experienced in utilizing this technique. The reproducibility of the method has been reported for a lotion containing lipid base. The results of the determination of aluminum in 3 different commercial products are presented. This method, because of its simplicity and sensitivity, provides a distinct advantage over methods previously reported in the literature.
Chromatographic-UV Spectrophotometric Determination of Menadione in Tablets
Authors: Bathalter William H , Levine Joseph
Published: February 2020

A chromatographic-UV spectrophotometric method for the determination of menadione in tablets, utilizing the conversion of menadione to menadione sodium bisulfite, has been developed. The sample is treated with sodium bisulfite and the resultant menadione sodium bisulfite is analyzed by the method of Johnson. A column prewash with CHCl3 removes impurities or degradation products present in the original menadione sample. The menadione is then eluted with an ammonia-saturated CHCl3 solution. The method worked equally well on coated and uncoated tablets and it has the advantage of determining only the amount of menadione and not degradation products present in the sample.
Comparison of Automatic and Manual Turbidimetric Analyses of Tylosin in Feeds with the Plate Method
Authors: Ragheb Hussein S , Breunig H Latham , Scroggs Robert E
Published: February 2020

Two laboratories participated in a comparison of a manual turbidimetric assay with the AUTOTURB® System and the AOAC method of analysis of tylosin in 4 feed samples. Results showed no significant difference between the 2 turbidimetric assays. When the AOAC method was considered, the difference between laboratories was significant. On an overall basis the turbidimetric methods were significantly higher than the plate method. The relative standard deviation was higher (6.72%) for the plate assay versus turbidimetric assay (4.5%). The mean recovery in both laboratories was significantly less than the labeled amount of tylosin by all 3 methods.
Determination of Ammoniacal Nitrogen in the Presence of Urea with an Ammonia Electrode
Authors: Woodis T C , Cummings James M
Published: February 2020

A recently introduced commercial electrode is shown to be suitable for the determination of ammoniacal nitrogen in the presence of urea. The results compare favorably with those of the reduced pressure distillation method. Standard deviations for the electrode method and the reduced pressure distillation method for ammoniacal nitrogen in urea ammonium phosphate are 0.12 and 0.09%, respectively.