bluuebunny/crossref_metadata_2025 huggingface dataset:
Collaborative Study of the Cation Exchange Capacity of Peat Materials
Authors: Thorpe Virginia A
Published: February 2020

To provide a measure of the total amount of exchangeable cations that can be held by peat expressed as mequiv./100 g air-dried peat, the modified method of Puustjärvi for cation exchange capacity has been proposed and studied collaboratively. The statistical treatment of the collaborators’ results indicate a satisfactory degree of precision and accuracy for the 3 products considered, moss, humus, and reed-sedge. The method for cation exchange capacity of peat materials, with the description of the transfer technique included, has been adopted as official first action. The 7 ASTM methods have been adopted as procedures.
Use of Isotopic Abundance Ratios in Identification of Polychlorinated Biphenyls by Mass Spectrometry
Authors: Rote James W , Morris William J
Published: February 2020

Polychlorinated biphenyls are industrial compounds which are being detected throughout the global ecosystem. Because of the presence of other residues, combined gas chromatography-mass spectrometry must be used for their confirmation. Using isotopic abundance ratios, the theoretical probability of the occurrence of ions of different masses in the molecular cluster has been calculated for the polychlorinated biphenyls, polychlorinated terphenyls, and chlorinated naphthalenes. Mass spectra of mono-through decachlorobiphenyl have been taken with a unit resolution, computer-controlled GC-MS system and parent ion clusters were matched with the theoretical isotopic patterns. This method provides the unambiguous identification of polychlorinated biphenyls in the presence of other substances.
Semiquantitative Microbiological Residue Method for Hygromycin B in Chicken Eggs
Authors: Begue William J , Kline Richard M
Published: February 2020

A method recently has been developed for the detection of hygromycin B residues in chicken eggs at the 15 ppb level. Protein is precipitated with trichloroacetic acid. After centrifugation, the supernatant liquid is adjusted to pH 7.0 and placed on an IRC-50 ion exchange column. The column is washed with water and then acetone, and subsequently the hygromycin B is eluted with ammonium hydroxide. The eluate is evaporated to dryness and reconstituted in a known amount of water; hygromycin B is microbiologically detected with Pseudomonas syringae by bioautography on thin layer chromatographic plates.
Electron Capture Determination of Melengestrol Acetate in Bovine Tissue
Authors: Krzeminski Leo F , Cox Byron L
Published: February 2020

An electron capture GLC method has been developed for the determination of melengestrol acetate (MGA) in frozen bovine tissue, which removes, through extraction, solvent partition, and chromatographic cleanup, most of the interfering materials before injection of the sample onto the column for detection. MGA is extracted from lean tissue with acetonitrile and partitioned against hexane to remove nonpolar impurities. MGA in fatty tissues is first extracted with hexane and then transferred into acetonitrile. The residue from either extract, after evaporation of the solvent, is chromatographed on an alumina column with hexane and a mixture of hexane-acetone to remove the interfering lipids. The MGA is then eluted with hexane-chloroform (1+1). The residue, after rotary evaporation, is dissolved in the appropriate volume of hexanemethanol (94+6) and injected onto a 2′ 1% OV-17 column in an all-glass system. MGA can be detected at 25 ppb (2–3 mm peak) with no interference from tissue or reagents. The observed recovery of MGA at 25 ppb in muscle, liver, fat, kidney, and bone marrow was 93 ±7%.
Collaborative Study of a Simplified Halphen Procedure for the Quantitative Determination of Low Levels of Cyclopropene Fatty Acids
Authors: Coleman Eugene C
Published: February 2020

A collaborative study was conducted on a simplified Halphen procedure for the quantitative determination of low levels of cyclopropene fatty acids. Twelve laboratories (some of these participated in a precollaborative study of this procedure) analyzed 9 samples, whose cyclopropene content ranged from 0.00 to 0.19%. The amount of cyclopropene fatty acids in the samples was estimated in the Associate Referee’s laboratory from HBr titration data. A statistical evaluation of the collaborative data indicated good precision and accuracy. Evidence for a significant between-laboratory systematic error could not be found. It is recommended that work be continued on development of a suitable calibration procedure and/or acquisition of a reference standard.
Fluorometric Determination of Estradiol Valerate in Sesame Oil or Ethyl Oleate Injectables. II. Collaborative Study
Authors: James Theron
Published: February 2020

A fluorometric method for determining estradiol valerate in sesame oil or ethyl oleate was subjected to collaborative study. The method utilizes a nitromethane-Celite column to isolate and purify the steroid, which is then measured fluorometrically. Four commercial samples and 3 synthetic samples, varying in concentration from 4 to 20 mg/ml, were used in the study. The collaborative results were acceptable: Coefficients of variation ranged from 2.48 to 3.55%; average recoveries for the synthetics ranged from 98.6 to 102%. The method has been adopted as official first action.
Distinction of Some Dialkyl Amides of Lysergic and iso-Lysergic Acids from LSD
Authors: Bailey Keith , Verner Denise , Legault Donald
Published: February 2020

The 10 lysergic and iso-lysergic acid amides described are N,N-dimethyl-, N,N-diethyl-, N-methyl-N-propyl, N-ethyl-N-propyl, and N,N-dipropyl-. Their ultraviolet spectra are insufficiently different for distinction. Mass spectra do not readily differentiate between isomers. Proton magnetic resonance spectra are distinct and provide a positive structural identification of the amide. Their infrared spectra are similar, but suitable for distinguishing these compounds from LSD. Various reference spectra are provided. Thin layer and gas-liquid chromatographic systems suitable for distinguishing these compounds from LSD are described.
International Aflatoxin Check Sample Program: 1972 Study
Authors: Coon Francis B , Baur Fred J , Symmes L Richardson L
Published: February 2020

In the second International Aflatoxin Check Sample Series, a single sample, peanut butter, was submitted to 152 laboratories throughout the world. Sufficient data were obtained from 117 responding laboratories to permit a statistical comparison of the BF, CB, and Pons methods. No significant differences in mean values were obtained. One quarter of the participating laboratories were from countries other than Canada and the United States.
Gas Chromatographic Determination of Ethylene Thiourea Residues
Authors: Haines Linwood D , Adler Irving L
Published: February 2020

Residues of ethylene thiourea on food crops are determined by extracting the sample with methanol, partially purifying the extract on an alumina column, and derivatizing the ethylene thiourea extracted with 1-bromobutane in the presence of dimethylformamide and sodium borohydride. The resulting derivative is measured by gas chromatography, using a flame photometric detector. The method is suitable for routine use and is sensitive to 0.01 ppm.
Residues of Lindane on Food and Utensils from a Thermal Lindane Vaporizer
Authors: Thomas R F
Published: February 2020

Food products and utensils were exposed to a thermal lindane vaporizer. The food products exposed showed residues from <0.01 to 0.61 ppm lindane. Exposed utensils showed residues of 0.01–6.00 μg per object. Air samples taken during the test showed up to 0.048 μg lindane/L after 5 days of vaporizer operation.
Collaborative Study of the Nonaqueous Copper Colorimetric and Silver Titrimetric Methods for the Determination of Malathion in Technical Grade Malathion and in Malathion Formulation
Authors: Wayne Richard S
Published: February 2020

The nonaqueous copper colorimetric and the silver titrimetric methods for the determination of malathion were studied collaboratively. The study involved wettable powders, emulsifiable concentrates, dusts, and the technical grade product. The mean of all of the results indicates that both procedures will give comparable values for each sample type used in the study. Agreement between replicates in individual laboratories was excellent. Agreement between laboratories was satisfactory; coefficients of variation ranged from 1.3 to 4.8% for the samples studied. The 2 methods offer improved reliability and ease of operation when compared to the official first action colorimetric method, 6.265–6.269. The methods have been adopted as official first action.
Collaborative Study of Methods for the Analysis and Control of AG-Chlordane and Its Formulations
Authors: Malina Marshall A
Published: February 2020

Four methods for the analysis of AG-chlordane and its formulations were submitted to a collaborative study. Fifteen laboratories, including 5 CIPAC laboratories, participated in this study. The infrared method for the analysis of the content of the 2 chlordane isomers was precise, with a coefficient of variation of 0.015. The gas chromatographic method for the analysis of the heptachlor content also yielded good precision with a standard deviation of 0.16. The infrared assay method for granular formulations exhibited excellent accuracy and precision, with a coefficient of variation of 0.067 and an error of only +0.25% relative. The gas chromatographic assay method for emulsifiable concentrates exhibited poor accuracy and precision and was found unacceptable. The first 3 methods have been adopted as official first action.
Gas Chromatographic Determination of Ethanol and Isopropanol or Acetone in Drugs
Authors: Falcone Nicholas
Published: February 2020

A gas-solid chromatographic technique, using flame ionization detection and a Porapak Q column, is presented for the identification and determination of ethanol and isopropanol or acetone in pharmaceutical products. The technique involves direct injection of an aqueous dilution of the product and is therefore simple and direct. The commercial products and 3 simulated mixtures, at various concentration levels, were analyzed by 9 collaborators. Recoveries and standard deviations for all 3 components were satisfactory. The method has been adopted as official first action.
Determination of Several Chlorinated Pesticides by the AOAC Multiresidue Method with Additional Quantitation of Perthane after Dehydrochlorination: Collaborative Study
Authors: Krause Richard T
Published: February 2020

The AOAC multiresidue method for chlorinated pesticides, 29.001–29.017, was studied collaboratively by 7 laboratories. Perthane, heptachlor epoxide, mirex, and dieldrin were determined in apple and cauliflower samples fortified at 2 levels, and Perthane was determined in butterfat samples fortified at 2 levels. Perthane was quantitatively measured before and after a simplified dehydrochlorination procedure. Average recoveries and coefficients of variations for pesticides in the apple samples for both levels were: Perthane 100±10%, heptachlor epoxide 102±14%, mirex 96±9%, dieldrin 101±14%, and Perthane (after dehydrochlorination and recalculation to the parent compound) 100±9%. Average recoveries and coefficients of variation for pesticides in the cauliflower samples for both levels were: Perthane 105±9%, heptachlor epoxide 103± 15%, mirex 103±7%, dieldrin 98±11%, and Perthane (after dehydrochlorination and recalculation) 100±10%. The average recovery for both levels of Perthane (after dehydrochlorination and recalculation) in the butterfat samples was 91±10%. For a spinach sample with field-incurred residues the collaborators found an average of 4.47 ppm Perthane before dehydrochlorination and 5.09 ppm Perthane as the olefin after dehydrochlorination. In most instances, the identities of all the residues were confirmed by TLC. The dehydrochlorination technique has been adopted as official first action.
Control of Authenticity of Fruit Juices by Isotopic Analysis
Authors: Bricout Jacques
Published: February 2020

In order to differentiate a natural fruit juice from a dilute concentrate, we have investigated the isotopic composition of their water. We have chosen the stable isotopes deuterium and 18O. The water of orange juices is strongly enriched in heavy isotopes, as compared to rain water. This enrichment is much lower for French apple juices and seems to be due to evapotranspiration. The relationship between deuterium and 18O observed for meteoric water is modified in the fruits. If a fruit juice is concentrated and then rediluted with natural water, the isotopic composition of its water would be very similar to the original deuterium and 18O content of the dilution water. Isotopic analysis allows a very confident distinction between natural fruit juices and reconstituted juices.
Use of Heat to Saponify Xanthophyll Esters and Speed Analysis for Carotenoids in Feed Materials: Collaborative Study
Authors: Quackenbush Forrest W
Published: February 2020

Twelve collaborators analyzed 4 pairs of samples to compare a 20 min hot (56°C) saponification technique with the overnight extraction technique at room temperature in the official first action method for analysis of carotenoids in feed materials, 39.018–39.023, with a view to (a) make the method applicable to products which contain xanthophyll esters and (b) speed up the analysis. In general, the collaborators were in good agreement, with saponification of esters essentially complete after the 20 min heating of samples that contained marigold meal. While the sum of extracted pigments from corn gluten and alfalfa meal tended to be slightly higher with the longer (overnight) contact with the solvent than with the hot extraction, the differences were not statistically significant. Significant differences between hot and cold treatments were absent also in alfalfa pigment fractions, but hot saponification significantly lowered monohydroxy pigments and increased dihydroxy pigments in extracts from corn gluten. The results showed good precision with either extraction technique. The method, modified to include hot saponification as an alternative step, is now applicable to all dried feed materials, including those which contain xanthophyll esters (e.g., marigold meal); the modification has been incorporated into the official first action method, 39.018–39.023.
Negative Finding of 2,3,7,8-Tetrachlorodibenzo-p-dioxin in Cooked Fat Containing Actual and Fortified Residues of Ronnel and/or 2,4,5-Trichlorophenol
Authors: Watts Randall R , Storherr Robert W
Published: February 2020

Beef fat containing residues of ronnel and its metabolite 2,4,5-trichlorophenol at 46.0 and 2.8 ppm, respectively, was examined before and after cooking for presence of 2,3,7,8-tetra-chlorodibenzo-p-dioxin. Fat samples fortified at 2000 ppm with 2,4,5-trichlorophenol or its sodium salt were cooked at 500°F for periods of 6 to 22 hr. No tetra-dioxin was found in any of the samples, using a method with a sensitivity limit of 0.05 ppm.
Rapid Detection of Aflatoxin Contamination in Agricultural Products
Authors: Pons Walter A , Cucullu Alva F , Franz Anthony O , Lee Louise S , Goldblatt Leo A
Published: February 2020

A rapid and simple method, originally designed for detecting aflatoxin contamination in cottonseed products within 15 min, was modified for application to a variety of agricultural products. The modified method involves rapid blender extraction of the sample with aqueous acetonitrile, treatment of an aliquot of the filtrate with lead acetate solution to remove interfering pigments, and rapid partition of aflatoxins in the treated extract into benzene to effect an 8-fold concentration of the aflatoxins. A portion of the benzene extract is adsorbed by capillary attraction onto the bottom of a small column (4 mm × 20 cm) filled with zones of acidic alumina and silica gel and the column is allowed to develop 5 min in chloroform-acetonitrile-2-propanol (93 + 5+2). Aflatoxin contamination is characterized by a sharp blue fluorescent band about 1 cm above the alumina zone when the developed column is viewed under longwave UV light. The total analysis time is about 20 min. The method was successfully applied to the oilseeds cottonseed, soybean, peanut, flax seed, and sunflower seed; to the grains corn, wheat, oats, barley, sorghum, rye, and rice; and to the tree nuts pistachios, almonds, walnuts, brazil nuts, pecans, and filberts. As little as 10 μg aflatoxin/kg can be detected, and approximate contamination levels can be placed in one of 5 categories, based on the observed intensity of the fluorescent aflatoxin band.
Microbiological Assay of Spectinomycin in Feed: Collaborative Study
Authors: Neff A William , Barbiers Arthur R , Miller Curtis C , Stahl Gerald L
Published: February 2020

A microbiological assay for the determination of spectinomycin in swine feeds has been developed and tested collaboratively in 9 laboratories. The design of the study involved 4 feed types and 4 levels of fortification (18, 20, 50, 55 g/ton) which represented the limits of permitted antibiotic usage. Statistical evaluation of the recovery data indicated that no real difference existed between feed types. Recoveries tended to be lower from lower content feeds than from the higher content feeds. The greatest source of variability came from the laboratory-to-laboratory component, followed by the random effects due to sampling, mixing, and assay techniques. The overall recovery was 96.4±13.4%.
Collaborative Study of a Method for the Atomic Absorption Spectrophotometric and Polarographic Determination of Cadmium in Food
Authors: Gajan Raymond J , Gould John H , Watts James O , Fiorino John A
Published: February 2020

The method studied involves acid digestion, dithizone extraction, and determination by atomic absorption spectrophotometry and polarography. This study consisted of 2 phases, with 10 laboratories participating in Phase I and 15 laboratories in Phase II. The 12 commodities studied (lettuce, potatoes, orange juice, shredded wheat, milk, sugar, eggs, fish, frankfurters, rice, beans, and oysters) were spiked at 0.05, 0.1, 0.2, 0.4, 0.5, 1.0, 1.5, and 2.0 ppm cadmium. Only 3 collaborators submitted polarographic results. There were no statistically demonstrable differences for the atomic absorption method between spiking levels, commodities, or laboratories. Coefficients of variation were acceptable. The atomic absorption spectrophotometric method for determining cadmium has been adopted as official first action.
Extraction and Cleanup for Determination of Polychlorinated Biphenyls in Paper and Paperboard
Authors: Young Susan J V , Alder Charles Finsterw , Burke Jerry A
Published: February 2020

A procedure is described for the determination of polychlorinated biphenyls (PCBs) in paper and paperboard. PCBs are extracted from the paper sample by reflux with alcoholic KOH. Column chromatography on Florisil is used for cleanup, if needed. Compounds are determined by GLC with electron capture detection, using conditions previously devised for organochlorine pesticides. An exhaustive extraction utilizing sulfuric acid was developed in order to obtain comparative data on extraction effectiveness. Recoveries of Aroclors 1242 and 1254 from fortified paper samples averaged 95.5 and 96.8% with the alcoholic KOH reflux and sulfuric acid digestion extractions, respectively. Aroclor 1242 determined after alcoholic KOH extraction of paperboard was 96% of the amount found after sulfuric acid digestion of comparable samples. Aroclor 1242 had been incorporated into the paperboard during manufacture.
Infrared Studies of Chlorinated Dibenzo-p-dioxins and Structurally Related Compounds
Authors: Chen Jo-Yun T
Published: February 2020

Reference infrared spectra of 24 chlorinated dibenzo-p-dioxins (DPD) and structurally related compounds are presented. These reference spectra are recorded using micro quantities of synthesized compounds in order to obtain spectra like those expected from chlorinated DPD residue isolates. The observed characteristic frequencies are tabulated in correlation tables. Their significance is interpreted in terms of the substituents and electronic effects. The positions of various absorption bands depend on the total number and positions of the chlorine substituents. The positions of the absorption bands indicate relative bond strengths.
Exhaustive Chlorination as a Technique in the Analysis of Aromatic Hydrocarbons
Authors: Hutzinger Otto , Jamieson W David J , Safe Stephen S , Zitko Vladimir Z
Published: February 2020

Perchlorination reactions of aromatic compounds have been further investigated. The preparation and properties of decachlorodiphenyl ether and the isomeric o-, m-, and p-tetradecaehloroterphenyls are described. Anthracene, as an example of a polycyclic aromatic hydrocarbon, gave octachloroanthraquinone when treated with the antimony pentachloride iodine reagent, but quantitative conversion to decachloroanthracene could not be obtained with reagent BMC (sulfuryl chloride-aluminum chloride-sulfur monochloide). A new reagent, trichlorosulfur tetra-chloroaluminate (SCl3+ AlCl4–), was shown to convert Aroclor 1254 to decadilorobiphenyl. As an application of the perchlorination technique it was shown that polychlorodibenzofurans (dibenzofuran) are not present at 0.5 μg/g in samples of Halowax 1014 and technical naphthalene, respectively. Well defined derivatives could not be obtained when phthalate esters or “hexabromobiphenyl” (fireMaster BP-6) were treated with the BMC or SbCl5–I2 reagents.
Determination of Aflatoxins in Mixed Feeds
Authors: Romer Thomas R
Published: February 2020

A complete extraction, purification, and cleanup method is described for the determination of aflatoxin in dairy, hog, horse, trout, and broiler finisher feeds. Thin layer chromatography is used for both confirmation and quantitative measurement of the aflatoxins. Average recovery for liquid spikes (3–100 ppb) was 92%. Average recovery found for feeds spiked (25 ppb) with cottonseed meal naturally contaminated with aflatoxin B1 was 80%. Sensitivities down to 2–4 ppb are possible with all the feeds tested. The method is also applicable to alfalfa, corn gluten meal, and fish meal, with a sensitivity of 2–4 ppb.
Determination of Maleic Hydrazide Residues in Tobacco and Vegetables
Authors: Ihnat Milan , Westerby Robert J , Hoffman Israel
Published: February 2020

The distillation-spectrophotometric method of Hoffman for determining maleic hydrazide has been modified to include a double distillation and was applied to the determination of 1–30 ppm maleic hydrazide residues in tobacco and vegetables. Recoveries of 1–23 μg added maleic hydrazide were independent of weight of maleic hydrazide, but did depend on sample and sample weight. The following recoveries were obtained from 0.5 g sample: pipe tobacco, 84%; commercially dehydrated potato, 83%; cigar tobacco, 81%; dried potato, 76%; fluecured tobacco, 73%; dried carrot, 71%. In the absence of sample, the recovery was 82%. When appropriate standard curves were used, maleic hydrazide levels determined in tobacco samples were essentially independent of sample weight in the range 0.1–3 g. The mean relative standard deviation for a variety of field-treated and fortified tobacco samples containing 1–28 ppm maleic hydrazide was 3%. The precision and sensitivity of this procedure seem to be substantial improvements over official method 29.111–29.117. It is recommended that the present method be subjected to a collaborative study.
Herbicide Analysis : Relationship Between Molecular Structure and Retention Index
Authors: Larose Richard H , Chau Alfred S Y
Published: February 2020

Retention indices are used to predict the retention time of the esters of chlorophenoxy acids. The total retention index is divided into 3 additive components: the alcohol contribution, the acid contribution, and the interaction contribution. This paper discusses 5 acids which are commonly used as herbicides, 8 alcohols, and 3 GLC columns.
Identification of cis- and trans-Cinnamoylcocaine in Illicit Cocaine Seizures
Authors: Moore James M
Published: February 2020

During the in-depth analysis of illicit cocaine samples small amounts of other coca alkaloids and cocaine degradation products have been detected. One of these alkaloids, cinnamoylcocaine, has been found in more than half of the samples examined, usually in concentrations of 1% or less of the amount of cocaine present. The presence of cinnamoylcocaine, as its cis and trans isomers, was established by column partition chromatographic isolation of the isomers, followed by ultraviolet, infrared, nuclear magnetic resonance, and mass spectrometric identification.
X-Ray Analysis of Forensic Samples, Using a Scanning Electron Microscope
Authors: Vasan Yel S , Stewart William D , Wagner J Bruce
Published: February 2020

A scanning electron microscope equipped with a wavelength dispersive spectrometer and an energy dispersive analyzer was used to examine paint chips and glasses. Line profiles of the elements in the paint show the non-uniform distribution of the pigments and extenders and, in order to obtain reproducible intensity ratios, a large area of the sample must be scanned. Layer analysis of the paint chip is possible with the energy dispersive analyzer and the resulting elemental profiles can be used to identify the chips. The difference in sodium concentration among the glasses studied provides a means of identifying the glass, but care must be taken to avoid migration of the sodium ions in the glass during electron beam bombardment.
Systematic Approach to the Detection of Explosive Residues. II. Trace Vapor Analysis
Authors: Washington Willard D , Midkiff Charles R
Published: February 2020

A Vapor Trace Analyzer (VTA) was found to be a valuable tool for scanning bomb debris for traces of certain types of explosives. The application of the VTA in screening bomb debris and locating secreted explosives and uses in other types of physical evidence is discussed. Thin layer chromatography is used to identify physically removed suspected explosive particles and samples from solvent extractions of blast material.
Gas Chromatographic Determination of Methyl Mercury in Fish, Sediment, and Water
Authors: Longbottom James E , Dressman Ronald C , Lichtenberg James J
Published: February 2020

Methyl mercury is extracted as the bromide salt from fish and sediment and as the chloride salt from water samples. All extracts are treated with a common cleanup procedure that results in the conversion of methyl mercury to the iodide salt for electron capture gas chromatographic analysis. Recoveries ranged from an average of 88.5% for water samples to averages of 95.5 and 96.3% for perch and sediments. Methods for controlling contaminants and interferences are discussed for all phases of the method. Particular problems encountered were column poisoning and detector poisoning. When the method was applied to sediment samples collected from a polluted river, a correlation could be established between total mercury and methyl mercury when the concentration of total mercury was in the 0–10 μg/g region. For samples of very high inorganic mercury, the correlation failed.
Observations on the Gas Chromatography of Kelthane (Dicofol)
Authors: Ives N Fred
Published: February 2020

Problems associated with the GLC of Kelthane (dicofol) are discussed. The contribution of inlet glass wool to the decomposition of dicofol to p,p′-dichlorobenzophenone is investigated and steps to minimize the problem are suggested. An impurity of the technical material, which eluted immediately after dicofol, was isolated and tentatively identified as 1,1-bis(p-chlorophenyl)-1,2,2,2-tetrachloroethane.
Spectrophotometric Determination of Gallotannins in Beer
Authors: Inskip Ervin B , King Perry , Ziegler Howard W
Published: February 2020

A method for the determination of traces of gallotannins in beer, in the presence of other natural tannins, has been developed. The procedure is based on the formation of a deep blue iron-tannin complex which is evaluated spectrophotometrically at 530 nm. Dimethyl sulfoxide is used to solubilize a haze that usually forms. Reproducibility of the method is quite good.
Comparison of Chicks and Rats as Test Animals for Studying Bioavailability of Iron, with Special Reference to Use of Reduced Iron in Enriched Bread
Authors: Pla Gwendolyn W , Harrison Bertha N , Fritz James C
Published: February 2020

Study was continued on the animal hemoglobin repletion test for measuring bioavailability of iron. With most iron sources, similar results were obtained with chicks and with rats. An important exception was noted with reduced iron. Seventeen samples were tested for solubility in dilute HCl and for bioavailability when fed to chicks and rats. The chicks utilized all samples reasonably well, but the rats were not able to efficiently utilize samples with particle sizes greater than 325 mesh. The mean relative biological value (vs. FeSO4 = 100) for the 17 samples was 50.5 ±8.3 when tested with chicks and 32.3±17.7 when tested with rats. Some, but not all, of the differences could be explained on the basis of particle size distribution. Similar relative biological values were obtained when the sample of reduced iron was added directly to the test diet or when it was used to enrich flour which was subsequently baked into bread and the bread was then added to the test diet. Plasma iron responses in human volunteers following test doses of the reduced iron samples were more closely related to the rat data, and this suggested that rats were the preferred species to measure bioavailability for man. The rat data also measured bioavailability of iron for guinea pigs.
Gas-Solid Chromatographic Determination of Propionates in Bakery Products
Authors: Jones Fitzhugh B
Published: February 2020

The bakery product sample is steam distilled, 10 ml distillate is evaporated, and the residue is dissolved in 1 ml dilute HCl. The propionate level is measured by gas-solid chromatography, using a Porapak Q column with a flame ionization detector and butyric acid as the internal standard. Recoveries of 5–30 mg propionic acid added to saltine crackers ranged from 97 to 102%. The method was checked by independent analyses and recoveries of 101 and 102% propionate were obtained.
Determination of FD&C Red No. 3 (Erythrosine) in Rat Blood Serum
Authors: Singh Manjeet , Graichen Charles
Published: February 2020

The extraction procedure used to isolate trace amounts of FD&C Red No. 3 (erythrosine) in rat blood serum is described. The blood sera from rats on diets containing FD&C Red No. 3 contained iodofluoresceins in such quantities that protein-bound iodine tests had no meaning. The lower iodinated subsidiary colors in FD&C Red No. 3 are absorbed and retained in the blood of rats to a greater degree than is tetraiodofluorescein, the main component of this color.
Polarographic Determination of Menadione Sodium Bisulfite in Pharmaceutical Preparations
Authors: Mayo Ana María , Nudelman Osmar
Published: February 2020

Menadione sodium bisulfite is reduced at pH 4 and determined by polarography, using a dropping mercury electrode. The method is simple and rapid and does not require special sample treatment. Average recoveries (%) and standard deviations for menadione sodium bisulfite added to synthetic mixtures at levels of 0.50, 1.00, and 5.0 mg were 99.88 ±2.12, 101.99±2.08, and 100.27±2.53, respectively.
Comparison of Methods for the Assay of Ethanol in Pharmaceutical Preparations, Cosmetics, and Alcoholic Beverages
Authors: Karawya Mohamed S , Hilal Sayed H , Elsohly Mahmoud A
Published: February 2020

Different methods, dichromate (iodometric and colorimetric), vanadate (spectrophotometric), critical miscibility temperature, and gas chromatography, were investigated for the determination of ethanol in various products. The results were compared with those from the official specific gravity method (USP and Egyptian Pharmacopoeia). The advantages and disadvantages, as well as the precision, are given for each method.
Indirect Method for Determination of Insoluble Solids in Processed Vegetable Products
Authors: Basker Dov
Published: February 2020

An indirect method for determining insoluble solids in processed vegetable products has been developed which avoids the problem of clogged filter paper that occurs in the direct method. Good agreement was obtained when apricots and onions were analyzed by the 2 methods.
Differentiation of Randhuni (Apium graveolens) and Ajowan (Carum copticum) by Thin Layer Chromatographic Separation of Their Essential Oils
Authors: Sengupta Pratima , Sen Asit R , Bose Anjali , Mathew T V
Published: February 2020

The volatile oils of randhuni and ajowan seeds are extracted and spotted on silica gel G thin layer plates. The plates are developed in either benzene-petroleum ether (1+1) or chloroform-pyridine-benzene (65+5+30). Spraying with anisaldehyde-sulfuric acid reagent shows a single red spot for ajowan and 4 spots (violet, greenish yellow, violet, and blue) for randhuni. This procedure can also differentiate admixtures of the 2 and seeds of other Umbelliferae.
Mercury-Free Raney Catalyst Method for Total Nitrogen in Fertilizers
Authors: Johnson Frank J , Woodis Terry C , Cummings James M
Published: February 2020

The original Raney catalyst powder method for total nitrogen was shown not to be applicable to nitric phosphates containing non-sulfate sulfur. Interference by the non-sulfate sulfur was eliminated by the addition of morin, a mordant dye, before the reduction. The method was modified further by omitting HgO, a possible pollutant, from the digestion and by shortening the digestion time. The modified method is highly rugged for a considerable range of fertilizer materials.
Methodology for Recovery and Identification of Enteropathogenic Escherichia coli
Authors: Mehlman Ira J , Sanders Arvey C , Simon Nicholas T , Olson Joseph C
Published: February 2020

Pathogenic biotypes of E. coli have been incriminated in food-borne illness. Sensitivity to elevated temperature and atypical behavior precluded assessment of their incidence. A tentative recovery procedure involves direct streak, preenrichment in MacConkey broth at 35°C and transfer to lauryl tryptose broth with incubation at 44°C, and pre-enrichment in nutrient broth at 35°C and transfer to enteric enrichment broth with incubation at 41.5°C. Serological examination of enrichment simplifies analysis. Levine's eosin methylene blue agar is recommended for rapid lactose fermenters; MacConkey's agar should be used for slow fermenters. Primary screening reactions include H2S, arabinose, urease, o-nitrophenyl-β-D-galactosidase, and indole. Secondary reactions comprise lysine decarboxylase, Voges-Proskauer (at 22°C), and other tests required to differentiate E. coli from Citrobacter diver sus, C. freundii, Enterobacter hafniae, Klebsiella pneumoniae, and Shigella species. Slide and tube agglutination reactions are necessary for identification of somatic and capsular antigens. Enhancement of motility by serial passage in a semisolid medium is essential for recognition of flagellar antigen. Confirmatory reactions include nitrate reduction, cytochrome oxidase, and Gram stain. Potentiality for quantitation, applicability to animal pathogens, and ecological samples are discussed.
Thin Layer Chromatography and in situ Fluorometry for the Quantitative Determination of Dimethoate and Malathion in Lettuce
Authors: Macneil James D , Maclellan Brian L , Frep Roland W
Published: February 2020

Dimethoate and malathion in spiked lettuce extracts are separated by thin layer chromatography on silica gel followed by in situ fluorometric determination. Fluorescence is produced by spraying the developed chromatogram with a palladium chloride-calcein reagent. A ligand exchange occurs in which the palladium complexes preferentially with the sulfur in the pesticide, releasing the metal-fluorochromic indicator calcein. For dimethoate, a linear response is obtained for 10—100 ng/spot and the need for a preliminary cleanup procedure is eliminated.
Qualitative Determination of Coal Tar Dyes in Alcoholic Products by Thin Layer Chromatography
Authors: Martin Glenn E , Figert Donald M
Published: February 2020

Thin layer chromatography can be used to determine coal tar dyes in alcoholic products. Hie dyes most commonly found in distilled spirits are FD&C Yellow No. 5, FD&C Red No. 2, and FD&C Red No, 4.
Determination of Siduron in Fertilizers by Flame Ionization Gas-Liquid Chromatography
Authors: Ealy Daniel B , Gorman Robert R , Kaiser Francis R , Scroggs Robert E
Published: February 2020

Siduron is formulated with fertilizers at about 2.4%. The herbicide is extracted with CHC13, using a magnetic stirrer, p,p'-methoxychlor is added as an internal standard, and the relative GLC peak heights are determined. The GLC column is 3% JXR on Gas-Chrom Q, and the mode of detection is hydrogen flame ionization.
Spectroscopic and Chromatographic Identification of Dimethoxyamphetamines
Authors: Bailey Keith , Legault Donald , Verner Denise
Published: February 2020

The qualitative analysis of the 6 isomeric dimethoxyamphetamines and their hydrochloride salts is described. Their ultraviolet spectra are insufficiently different for distinction, but mass, proton magnetic resonance, and infrared spectra allow a positive identification to be made, and reference spectra are provided. The application of gas-liquid and thin layer chromatographic systems for the analysis is discussed.
Spectrophotometric Method for Simultaneous Determination of Anthocyanogens and Catechins (Tanninogens)
Authors: Dadic Miroslav
Published: February 2020

An earlier method for the simultaneous determination of anthocyanogens and catechins (tanninogens) in beer, wine, and brewing materials has been modified to include Polyclar AT and Polyamide Woelm 400 as the adsorbents. The results are presented, along with the values obtained using Nylon-66 for comparison. Nylon-66 and Polyamide Woelm 400 are the adsorbents of choice, yielding similar results, while Polyclar AT gives lower tanninogen values. The method is further applied to determine the anthocyanogen and catechin contents of solids, without the use of tanninogen adsorbents. Lyophilized beer, “testinic acid,„ and humic acid samples were thus analyzed. The present method is recommended for the simultaneous determination of catechins and anthocyanogens in any tanninogen-containing materials.
Improved Colorimetric Determination for Furfural in Citrus Juices
Authors: Dinsmore Howard L , Nagy Steven
Published: February 2020

An improved colorimetric method for furfural in citrus juices, which is based on the well known aniline-acetic acid reaction with furfural (Stenhouse reaction), is described. Addition of SnCl2 and HCl yielded higher intensity and improved color stability. The reagent giving the best results contained 1% SnCl2, 0.6N HCl, and 10% aniline in glacial acetic acid.
Determination of Pentachlorophenol in Natural and Waste Waters
Authors: Chau Alfred S Y , Coburn John A
Published: February 2020

A sensitive and reliable method suitable for routine determination of pentachlorophenol (PCP) in natural and waste waters is reported. PCP is extracted from the preserved sample with benzene and from the benzene into a potassium carbonate solution. The addition of acetic anhydride to the aqueous solution produces the acetate derivative of PCP, which is extracted in hexane and analyzed by electron capture gas-liquid chromatography. The analysis of PCP in lake water and sewage effluent is presented, along with the retention times of 17 other phenolic acetates. By this procedure, as little as 0.01 ppb PCP in 1 L water can be determined.
Confirmation of Pesticide Residue Identity. VI. Derivative Formation in Solid Matrix for Confirmation of Heptachlor and Endosulfan Isomers
Authors: Chau Alfred S Y , Terry Ken
Published: February 2020

An alternative method for the confirmation of heptachlor residue identity is described. This method entails derivation in a solid matrix prepared from alumina and sulfuric acid to obtain a single derivative in almost quantitative yield.
Gas-Liquid Chromatographic Determination of Sodium Fluoroacetate
Authors: Stahr Henry M , Buck William B , Ross Paul F
Published: February 2020

Sodium fluoroacetate is extracted from biological samples, esterified, and determined by GLC, using a Resoflex column. The identity of the rodenticide is confirmed by a fluoride electrode procedure or by GLC/MS. The method can detect as low as 0.1 μg sodium fluoroacetate.
Rapid Screening Method for Analysis of Chlorinated Pesticide and Polychlorinated Biphenyl Residues in Fish
Authors: Ronald Erney D
Published: February 2020

Ground fish is dried with anhydrous Na2S04, packed into a chromatographic column, and extracted with petroleum ether. An aliquot of extract is cleaned up on miniature chromatographic columns of Florisil and silica gel. GLC analyses of a variety of fish samples by both the proposed procedure and multipesticide residue methods gave comparable results. The described procedure is rapid, economical, and applicable to routine analysis of fish samples.
Confirmation of Pesticide Residue Identity. VII. Solid Matrix Derivation Procedure for the Simultaneous Confirmation of Heptachlor and Endrin Residues in the Presence of Large Quantities of Polychlorinated Biphenyls
Authors: Chau Alfred S Y
Published: February 2020

Heptachlor is converted almost quantitatively (90%) to 1-hydroxychlordene, and endrin is converted to the ketone in 75% yield. Because of the diversity in polarity of these derivatives and the unreacted polychlorinated biphenyls, they are clearly separated. This procedure has been applied routinely to extracts obtained from fish, sediment, and water samples.
Colorimetric Method for Estimation of Carbaryl and Its Residues on Grains
Authors: Rangaswamy Jois R , Majumder Suvendu K
Published: February 2020

A new colorimetric method for the estimation of carbaryl, 1-naphthyl JV-methylcarbamate, based on its reaction with diazotized o-toluidine, has been described. The absorption maximum of the red color formed is measured at 520 nm. The method is sensitive to 0.1 fig carbaryl/20 g sample, with an estimation limit of 1 /ig, and can be applied to 10% dust formulations of carbaryl.
Quantitative Gas-Liquid Chromatographic Determination of Ethyl Esters and Isoamyl Acetate in Whiskies and Rums and Confirmation by Mass Spectrometry
Authors: Martin Glenn E , Dyer Randolph H , Buscemi Peter C
Published: February 2020

A gas chromatographic method is described for determining isoamyl acetate and the ethyl esters caproate, caprylate, caprate, laurate, myristate, and palmitate in whiskies (Scotch and bourbons, light and Canadian) and rums (Caribbean and New England). A 4 0% ethanol solution saturated with salt was reduced to 5—10% ethanol by adding a saturated salt solution and extracting 3 times with pentane. For whiskies, the isoamyl acetate ranged from none detected (ND) to 4.5 ppm, ethyl caproate from ND to 3.9 ppm, ethyl caprylate from 0.9 to 16 ppm, ethyl caprate from 1.1 to 20.6 ppm, ethyl laurate from ND to 7.5 ppm, ethyl myristate from ND to 10.0 ppm, ethyl palmitate from ND to 8.0 ppm, and ethyl acetate from 69.4 to 717 ppm. The Caribbean rums showed the lowest concentration of ethyl esters and the New England rum showed the greatest concentration of these ethyl esters (C6 through C16). This method did not detect below 0.1 ppm. The identity of these esters was confirmed by gas-liquid chromatography- mass spectrometry.
Collaborative Study of the Determination of Lead in Alkyd and Latex Paints
Authors: Porter Warren K
Published: February 2020

A collaborative study was conducted on the determination of lead in alkyd and latex paints by atomic absorption spectrophotometry after nitric acid digestion. Fourteen samples of blank paints and paints with known additions of lead were analyzed by 10 collaborators. Coefficients of variation from 4 to 16% were obtained for 0.33 to 0.02% lead in the paint solids. The statistical analysis indicates minimal bias and adequate precision for the analysis of lead in paints at the current regulatory limit (0.5% in the paint solids or dry paint film). The method has been adopted as official first action.
Collaborative Study of the Infrared Spectrophotometric Determination of Aldicarb in Formulations
Authors: Mcdermott William H
Published: February 2020

An infrared method for the determination of aldicarb in formulations was studied collaboratively. The carbamate carbonyl infrared absorption band at 5.75 μm of the aldicarb is measured after extraction of the aldicarb from the formulation with methylene chloride in a Soxhlet extractor. A statistical evaluation of the data by the technique of matched pairs at the 10% level shows a random standard deviation of 0.21%, a systematic standard deviation of 0.26%, and an overall standard deviation of 0.43%. The method has been adopted as official first action.
Determination of Carbaryl in Pesticide Formulations and Fertilizers by High-Pressure Liquid Chromatography
Authors: Colvin Billy M , Engdahl Barbara S , Hanks Alan R
Published: February 2020

A simple and rapid method is described for the determination of carbaryl in pesticide formulations by high-speed liquid chromatography. Carbaryl is extracted with 10% methanol in chloroform and pentachlorophenol is added as an internal standard. The sample extract is injected into a liquid chromatograph, and peak height ratios are used for quantitative measurement. Chromatography is complete in 8 min. The method compares favorably with infrared, near infrared, and colorimetric procedures for carbaryl.
Use of the AOAC Fluorometric Method for Selenium in Plants for the Analysis of Papers and Tobaccos
Authors: Leisure Orie W , Olson Oscar E
Published: February 2020

Additional studies of the AOAC fluorometric method for selenium, 3.074—3.078, were undertaken to determine if the method is applicable to paper and processed tobacco samples. The recovery of added selenium, the use of oxygen flask combustion, and neutron activation analysis without chemical separation of the element were studied. The studies all indicate that the results with the fluorometric method are not too low. It is concluded that this method is satisfactory for the analysis of processed tobaccos. It is less useful for the analysis of paper, since its selenium content is often about 0.02 ppm, the lower limit of the sensitivity of the method.
Absorption-Elution Testing for ABO Blood Group Factors: Preliminary Collaborative Study
Authors: Fox Richard H
Published: February 2020

Four laboratories participated in a study of an absorption-elution method for the determination of ABO factors in dried human blood. In the method studied, normal saline solution is used for the incubation for elution and whole blood cells are added after incubation; thus, the whole cells are not subjected to excessive temperature for a prolonged period of time. Each collaborator received 5 dried stains of human blood on clean cotton cloth. Three of the 4 collaborators correctly typed each of the 5 samples submitted to them. The fourth did not report the A factor but did report the B factor of an AB blood stain. The data show no false grouping report. Based on the results of this study, it is recommended that the absorption-elution test be subjected to a larger collaborative study.
Isolation, Identification, and Quantitation of o-Toluenesulfonamide, a Major Impurity in Commercial Saccharins
Authors: Stavric Bozidar , Lacombe Richard , Watson Jim R , Munro Ian C
Published: February 2020

o-Toluenesulfonamide (o-TS) was found to be a major impurity in 9 of 10 different saccharin samples used for carcinogenicity tests in animals in various laboratories. Isolation of o-TS from sodium saccharin was achieved by extraction with ethyl acetate, and separation was accomplished by using thin layer chromatography. Saccharin samples obtained in the free acid form were first converted to their sodium salts. o-TS was identified by Rf and ultraviolet, infrared, and mass spectra. Quantitative determination of o-TS was performed by gas chromatography. The concentration of o-TS in the samples ranged from 2.5 to 5050 ppm.