bluuebunny/crossref_metadata_2025 huggingface dataset:
Collaborative Study of the Analysis of Mestranol in Combination with Norethindrone or Norethynodrel
Authors: Brunner Charlotte A
Published: February 2020

A collaborative study was conducted on the analysis of mestranol in combination with norethindrone or norethynodrel by partition chromatography and UV measurement. The test preparations consisted of 4 samples: a composite of norethindrone commercial tablets and the corresponding synthetic mixture, and a composite of norethynodrel commercial tablets and the corresponding synthetic mixture. Single analyses were performed on each of the samples by 13 collaborators. The average per cent recovery was 100.4, 99.9, 98.7, and 101.2%, respectively. The method has been adopted as official first action.
Collaborative Study of the Colorimetric Determination of Progestational Steroids in Contraceptive Tablets
Authors: Wu John Y P
Published: February 2020

A collaborative study of the proposed method for progestational steroids in oral contraceptive tablets has been conducted. Both the tablets of commercial brands and simulated tablet mixtures of norethynodrel, norethindrone, and medroxyprogesterone acetate were assayed by the proposed method. Average recoveries of the steroids ranged from 95.30 to 101.91% of the declared amounts of commercial tablets, and 97.77 to 99.20% of the added quantities in simulated samples. The method has been adopted as official first action.
Collaborative Study of a Method for Determining the Fish Flesh Content of Frozen Breaded Fish Products
Authors: Werren John C , Allhands Frank H
Published: February 2020

Eight laboratories studied the modified USDI method for determining the fish flesh content of frozen breaded fish products. Four different samples of 10 units each were analyzed for per cent fish flesh. Some recovery difficulty was encountered with the precooked fish stick sample. Statistical analysis indicated that the problem was related to a prolonged high temperature (120°F) dip and this has been corrected. Satisfactory reproducible precision was obtained. The method has been adopted as official first action.
Collaborative Study of the Colorimetric Determination of Sorbic Acid in Cheese
Authors: Wilamowski George
Published: February 2020

After isolation of sorbic acid from cheese by steam distillation, the acid recovered is cleaved with potassium dichromate in acidic medium to form an intermediate malonaldehyde, which, in turn, reacts with 2-thiobarbituric acid to produce a red dye. The absorbance of the red color, measured at 532 nm, is proportional to the concentration of sorbic acid in the sample. Seven collaborators reported recoveries of 96.7–102.4% from cheese samples spiked with 0.05% sorbic acid. This method has been adopted as official first action.
Collaborative Study of Copper in Feeds by Atomic Absorption Spectrophotometry
Authors: Heckman Mary
Published: February 2020

Eleven laboratories collaborated in a study of the analysis of copper in feeds by atomic absorption spectrophotometry. Four feeds containing varying levels of copper were prepared by several dry-ashing methods and by wet digestion. Results indicate that the method is satisfactory. The method has been adopted official first action.
Pepsin-Digestibility Method for Animal Proteins
Authors: Gehrt Albert J
Published: February 2020

The official method for pepsin digestibility of animal proteins, 7.040-7.046, has been improved by replacing the centrifuge isolation of the indigestible residue with filtration through glass fiber paper. The modified method was studied by 25 collaborators. The study included meat meals, digester tankage, fish meal, blood meal, poultry by-product meal, and hydrolyzed feathers. The filtration method is more rapid, less laborious, and free from decantation losses. Basic digestion conditions of the official method, pepsin concentration, acidity, digestion time and temperature, and continuous agitation, are unchanged. The study also included grinding the portion of the samples that was larger than 20 mesh. Agreement between replicates in individual laboratories was excellent. Agreement between laboratories on all samples except poultry byproduct meal and hydrolyzed feathers was satisfactory; standard deviations ranged from 0.43 to 1.07. Data indicate that part of the variation was due to slight differences in the samples. The modified method has been adopted as official first action for all animal proteins except poultry by-products and hydrolyzed feathers.
Collaborative Check for Paraquat in Formulations
Authors: Carlstrom A A
Published: February 2020

A collaborative test was conducted by the Association of American Pesticide Control Officials, Inc. on the official first action colorimetric method for paraquat in formulations, 6.160–6.163. The standard deviation for a 2 lb/gal. formulation (20% cation) was 0.32, based on results from 27 analysts. The method has been adopted as official final action.
Modifications of the Official GLC Method for Volatile Acids in Eggs
Authors: Starling Michael K , Staruszkiewicz Walter F , Salwin Harold
Published: February 2020

During the past year, this laboratory has made extensive use of the AOAC gas chromatographic method for the determination of volatile acids in application to eggs. Our experience has led to the development of several modifications that provide greater flexibility, speed, and economy without altering the chemical approach of the method. The hasis for some of these modifications was established in the more recently developed gas chromatographic method for lactic and succinic acids. This report describes these alternatives and several observations that were made. Specific details of the modifications are presented. The method as modified has been adopted as official first action as an alternative to 17.040, 17.041, and 18.035–18.038.
Collaborative Study of the GLC Determination of β-Hydroxybutyric Acid in Eggs
Authors: Staruszkiewicz Walter F , Starling Michael K
Published: February 2020

The GLC method for the determination of β-hydroxybutyric acid in eggs was submitted to collaborative study. The collaborators analyzed passable and incubator-reject eggs as well as mixtures of the 2 types. The organic acids were extracted into ether, their propyl esters were formed by reaction with BF3-l-propanol, and the esters were quantitatively measured by gas-liquid chromatography. Lactic and succinic acids were determined simultaneously along with β-hydroxybutyric acid. All collaborators were able to distinguish between passable eggs and samples containing incubator-reject eggs. The method has been adopted as official first action.
Determination of Carbon Dioxide in Wine
Authors: Caputi Arthur
Published: February 2020

A study of the various official methods available for the determination of carbon dioxide in wine was conducted. The enzymatic method, which is the fastest of the 3 available, is still relatively slow for use as a control analysis when large quantities of wines are being bottled at high speeds. A new method was devised which involves the neutralization of a wine sample with 50% NaOH to pH 10–11 and titration with a standard acid solution in the presence of carbonic anhydrase. The titer is recorded between pH 8.6 and 4.0. A degassed sample of the same wine is neutralized and titrated in the same range and its titer is subtracted from the sample titer. The difference is used to calculate the carbon dioxide concentration in the sample. Comparison to the volumetric, manometric, and enzymatic methods showed that this new titrimetric method is comparable in terms of accuracy and reproducibility and that it offers the advantage of rapidity of analysis. It is recommended that the method be studied collaboratively.
Collaborative Study of a Zincon Ion Exchange Method for the Quantitative Determination of Zinc in Fertilizers
Authors: Jones C E , Pracht L E
Published: February 2020

This collaborative study represents an attempt to validate the ion exchange zincon method for the quantitative determination of zinc in fertilizers. The values of the standard deviations Sd, Sr, and Sb and the results of the F- and t-tests are presented as an estimate of the precision, accuracy, and dependability. Atomic absorption measurements were also made and provided reference data for evaluation purposes. In its present form, the method falls short of expectations as an alternative wet approach to the dithizone method. It is recommended that the methods for determining zinc in fertilizers be studied further.
Refinement of a Quantitative Technique for Estimating Alkaline Phosphatase Activity in Milk
Authors: Huaxg C L , Kleyn D H
Published: February 2020

A procedure for determining alkaline phosphatase activity in milk and chocolate milk, based upon the dialysis of phenolphthalein monophosphate and subsequent measurement of absorbance of the dialysate at 550 nm, has been refined. The modified procedure specifies 3 ml milk, 3 drops (0.04 ml/drop) of substrate, and a 3 hr incubation period. These changes have resulted in a decrease in the cost of reagents and higher, more suitable absorbance values. The Scharer modified Spectrophotometric method was used as a reference. The modified method showed an apparent linear relationship which was verified by calculating correlation coefficients, 0.996 for milk and 0.992 for chocolate milk; both of these values are significant at the 1% level.
Evaluation of Reflectance Fluorodensitometry for Measuring Aflatoxins on Thin Layer Plates
Authors: Pons Walter A
Published: February 2020

A reflectance fluorodensitometer employing illumination of chromatograms with longwave UV light at 45° angles to the plate surface and measurement of reflected fluorescence at 90° was found to be suitable for measuring aflatoxins on silica gel-coated thin layer plates. The relationship of peak area vs. concentration was linear for 1–20 ng aflatoxins B1 and G1/ spot. Degradation of aflatoxins was slight. Five repetitive scans of the same chromatogram containing 5 ng each of B1 and G1 reduced the recorded areas an average of 1% per scan. Consecutive scans of 8 identical standard chromatograms containing 5 ng each of B1 and G1 and 1.5 ng each of B2 and G2 showed a reproducibility, as measured by coefficients of variation, of ±4–5% (B1 and G1) and ±5–9% (B2 and G2), representing the combined errors of standard application, TLC development, and scanning. Analysis of aflatoxins in purified sample extracts from 6 contaminated oilseed meals, 3–500 μg afla toxins/kg, in which the same TLC plates were scanned by a transmission densitometer and the reflectance densitometer yielded essentially equivalent values.
Gas Chromatographic Determination of Safrole and Related Compounds in Nonalcoholic Beverages: Collaborative Study
Authors: Larry Damon
Published: February 2020

A method for the GLC determination of methyl salicylate, safrole, and related compounds in nonalcoholic beverages was studied collaboratively and reported previously. Only the methyl salicylate analysis gave acceptable precision and accuracy at all spiking levels. The study was continued and the optimum conditions for the analysis of safrole were selected. The present collaborative results show that average recoveries for safrole ranged from 77 to 98% with more variable recoveries obtained for isosafrole, dihydrosafrole, and dihydroanethole. The method has been adopted as official first action for the quantitative determination of safrole and for the semiquantitative determination of the 3 related components in nonalcoholic beverages.
Forensic Applications of Spark Source Mass Spectrometry
Authors: Harrison W W , Clemena G G , Magee C W
Published: February 2020

Spark source mass spectrometry provides unique capabilities in trace elemental analyses which have been useful in the examination of materials of forensic interest. Response of this technique to all inorganic elements, sensitivities to the ppb range, and qualitative-quantitative data display allow acquisition of trace element “profiles” for comparison and identification purposes. Sample preparation and pretreatment is quite important. Instrumental parameters must also be carefully controlled, including spark conditions, electrode position, and ion flux. Materials studied in our laboratories include metallurgicals, synthetic fibers, and graphites as well as human hair, blood, nails, and tissues.
Simplified Fluorometric Determination of Chlortetracycline in Mixed Feeds
Authors: Katz Stanley E , Fassbender Carol A , Dorfman Donald
Published: February 2020

The procedure described is based upon the alkaline conversion of Chlortetracycline to the corresponding isochlortetracyclines. The isochlortetracyclines fluoresce with equivalent intensity at the same activation and emission wavelength. Direct dilution of feed with ammonium hydroxide to levels similar to microbiological assay concentrations, the use of a feed matrix to eliminate problems of fluorescence interference from feeds, and a sensitive optical system permit the simplified assay of feeds at levels as low as 25 g/ton. Agreement with the microbiological assay is good.
Extraction Efficiency Study—Examination of Three Procedures for Extracting 14C-Labeled and Unlabeled Residues of Organophosphorus Pesticides and Carbaryl from Bean Leaves and Kale
Authors: Watts Randall R
Published: February 2020

Two rapid extraction procedures which consist of sample blending with ethyl acetate or acetonitrile and an exhaustive Soxhlet extraction procedure using 10% methanol in chloroform were tested for efficiency of extraction of 14C-labeled residues of carbaryl, malathion, and phosphamidon on laboratory-grown and treated bean plants. The extraction procedures were also tested on field-treated kale containing 7–11 day old residues of azinphosmethyl, parathion, and malathion. The extraction efficiencies of the 3 procedures were in very close agreement for all residues in both studies. More than 90% of the 14C-containing residues were extracted from treated bean leaves. The extraction efficiencies for field-weathered residues on kale were judged to be essentially 100%, since several hours of additional Soxhlet extraction did not remove any more residue.
Extraction and Identification of Endrin and Heptachlor Degradation Products
Authors: Nash R G , Beall M L
Published: February 2020

Two endrin degradation products and a heptachlor degradation product, in addition to heptachlor epoxide, were extracted from soybean plants grown in soil treated with 14C-endrin or 14C-heptachlor. One endrin product was identified as 1,8,9,9,10,11-hexachloropentacyclo[6.3.0.12,5.03′7.06,10]dodecan-12-one (endrin delta ketone); the second endrin product was identified as 1,8,9,9,10,11-hexachlorohexacyclo-[6.3.0.12′5.03,7.06,10.011,12]dodecan-12-ol (endrin alcohol); and the heptachlor product was identified as l,7,8,9,10,10-hexachloro-2,3-6,5-endo-tricyclo[5.2.1.02′6]deca-4,8-diene-exo-3-ol (hydroxychlordene). Identifications were by multiple GLC and TLC techniques.
Analysis of Commercially Fumigated Grains for Residues of Organic Fumigants
Authors: McMahon Bernadette Malone
Published: February 2020

Seven lots of commercially fumigated grains were sampled from storage bins and analyzed for residues of the organic fumigants. Residues were isolated by the acid reflux procedure and determined by gas-liquid chromatography. Residue levels ranged from 0.84 to 2.16 ppm carbon disulfide, 2.92 to 20.4 ppm carbon tetrachloride, and <0.01 to 6.10 ppm ethylene dibromide. In general, residue levels found on grains fumigated at different times indicated the tendency for the volatile fumigants to dissipate with time. The lower volatility of ethylene dibromide results in disproportionately high residues compared to carbon disulfide and carbon tetrachloride, which were applied at higher rates.
Proteolytic Activity of Papain
Authors: Cayle Theodore
Published: February 2020

A method based on the ultraviolet absorption of the hydrolytic products of casein digestion and expression of the results as tyrosine equivalents was adopted in 1966 by the Pharmaceutical Manufacturers Association and the Food Chemicals Codex. Based on the collaborative data obtained in 2 studies the method has been adopted by the AOAC as an alternative to 20.114–20.117.
Determination of Carotene and Xanthophyll in Alfalfa Products
Authors: Livingston A L , Knowles R E , Kohler G O
Published: February 2020

The addition of an increment of water to the extracting solvent increased the extraction of xanthophyll from dehydrated alfalfa meals but not from lyophilized meals. Results of the analysis for carotene and xanthophyll compared favorably with analysis by AOAC method 39.018–39.023.
Free and Total Water in Fertilizers
Authors: Duncan R D
Published: February 2020

Methods for the determination of free and total water in fertilizers are based on the Karl Fischer titration. Free water is extracted with 1,4-dioxane, and total water is separated by azeotropic distillation with n-amyl alcohol. Results of a preliminary collaborative study were in wide disagreement. It is recommended that the method be written in more explicit detail before further collaborative study.
Rapid Low-Cost Moisture Determination System
Authors: Solberg M , Riha W E
Published: February 2020

The Ohaus 770-moisture determination system, a rapid low-cost moisture-determining system based upon infrared heating, was evaluated. Several types of frankfurters and ground fresh meat were tested. The results obtained were comparable to those obtained by the official AOAC air oven method.
Collaborative Study of the Determination of Tar and Nicotine in Cigarette Smoke: 1970 Study
Authors: Ogg C L , Schultz E Fred
Published: February 2020

A collaborative study was made to evaluate the effects of (1) reducing the number of cigarettes per port, (2) using sleeves vs. dams for sealing the cigarette in the holders, and (3) pooling filter pads before water and nicotine analyses. None of these variables had a significant effect on the precision of the method. The statistical data obtained from this study agreed closely with those reported last year.
Lipid Changes Associated with the Degradation of Fish Tissue
Authors: Wood Garnett , Hintz Lane
Published: February 2020

The stability of fish lipids during storage of fish tissue at ice temperature was investigated. Homogenized tissue from rockfish (striped bass, Roccus species) was stored 16 days at melting ice temperature. Lipids were extracted at intervals and separated into various components by silicic acid column chromatography. Changes in the weights of individual lipid components were correlated with gas chromatographic data on changes in individual acids of these components. In the fresh tissue, the phospholipid fraction contained the highest proportion of polyunsaturated acids and the neutral lipid fraction contained the highest proportion of monounsaturated acids. During storage of the tissue, there were decreases in the weights of total phospholipids and neutral lipids and an almost equivalent increase in the amount of free fatty acids. Although there were changes in all acids during storage, the polyunsaturated acids, eicosapentaenoic (C20:5) and docosahexaenoic (C22:6), were affected most and were lost at a faster rate from phospholipids than from neutral lipids. The loss of polyunsaturated acids was apparently by a selective process because most of the loss was from the cephalin fraction, even though it contained only about ¼ of the total polyunsaturated acids. Relatively small amounts of these acids were lost from the neutral lipids and virtually none from the lecithin.
Preparation of 14C- and 3H-Labeled Aflatoxins
Authors: Ayres J L , Lee D J , Sinnhuber R O
Published: February 2020

A new method for the preparation of 14C- and 3H-labeled aflatoxins was devised, using rice as a supporting mold media. Labeled precursors were added to sterile rice and the mixture was inoculated with Aspergillus flavus spores. After a 7 day incubation at 25°C, the toxins were extracted with chloroform and purified by column chromatography and subsequent recrystallization. Aflatoxins B1 and G1 were recovered with 70% efficiency from the culture. Incorporation of radioactivity was examined with glucose-U-14C, sodium acetate-1-14C, and sodium acetate-2-14C. The latter gave the most efficient incorporation of 14C at 0.1% for aflatoxin B1 and 0.05% for aflatoxin G1. Conversion of 3H from tritiated water was 0.006% for aflatoxin B1 and 0.003% for aflatoxin G1. Extensive tests of radiopurity were performed on the labeled toxin which included: recrystallization to constant specific activity, thin layer and column chromatography, and hydrogenation of aflatoxin B1 to tetrahydrodeoxoaflatoxin B1. The rice-culturing technique gave good toxin yields of 1 mg aflatoxin B1/g rice. The purification was simplified by the absence of highly radioactive impurities and no appreciable degradation of labeled toxins was noted throughout extraction and purification.
Detection of Clostridium botulinum Type E in Smoked Fish
Authors: Kautter Donald A , Lilly Timothy
Published: February 2020

Smoked whitefish chubs artificially contaminated with small numbers of Clostridium botulinum type E spores gave as many positives with no apparent loss of toxicity in 5 days at 30°C as at 26°C in an enrichment medium containing 1 mg trypsin/ml. However, failure to increase the detection of proteolytic type B spores under the same conditions was not corrected by incubation at 30°C. Therefore, no alteration of the conditions most suitable for type E was made. Collaborative study is recommended.
Routine Estimation of Captan on Individual Sorghum Seeds
Authors: Simon Paul W , Kulik Martin M
Published: February 2020

A colorimetric method to delect captan was modified to permit rapid estimation of this fungicide on individual sorghum seeds. The procedure involves extraction of captan with benzene, removal of interfering dyes with Florisil, reaction with a resorcinol solution, and determination of color intensity with a colorimeter. One hundred seeds from each of 11 commercially treated samples were tested. The seeds numbered from 116,000 to 161,000/ lb. The average amount per sample of captan removed from seeds varied from 10.6 to 28.9 μg/seed and from 0.307 to 1.032 μg/mg seed weight. The theoretical amount of captan should have been 0.975 to 1.400 μg/mg seed weight, according to the container labels. The results indicate the need for closer control of seed treatment and for better definition of amounts of treatment required for adequate seed protection. The method presented now makes it feasible for seed testing laboratories to routinely determine amounts of captan on individual seeds. One technician could probably analyze up to 600 seeds daily, using equipment of larger capacity than the prototypes described in this paper.
Removal of Sulfur in Environmental Samples Prior to Gas Chromatographic Analysis for Pesticide Residues
Authors: Schutzmann R L , Woodham D W , Collier C W
Published: February 2020

Extracts of soil, water, and sediment often contain large amounts of elemental sulfur. This sulfur causes considerable interference in the GLC analysis of early eluting compounds by electron capture or flame photometric detection systems. A method is described whereby sulfur is removed by refluxing with a copper-aluminum alloy. Using a sample volume of 1 ml, up to 50 ppm elemental sulfur can be removed. Recovery of chlorinated pesticides from desulfurized extracts is >80%. Parathion and malathion gave recoveries of approximately 50%.
Gas-Liquid Chromatography of Morestan Residues in Plants
Authors: Tjan G H , Konter Th
Published: February 2020

Two methods are described for the analysis of Morestan residues in plants. The first method is based on an acetonitrile cleanup, similar to the method of Mills et al.; the second involves a simple extraction with benzene. The extract solutions can be injected directly into a gas chromatograph without further cleanup. A capillary column at 200°C, packed with 5% QF-1 or DC-200 on Chromosorb W (AW), and an electron capture detector are used. Results of these studies indicate that the acetonitrile method and the rapid benzene method are applicable for the analysis of Morestan residues at a level of 0.1 ppm. Recoveries of 92-99% were obtained from 4 fruits and vegetables fortified with 0.1-0.5 ppm Morestan.
A Compact Extraction Apparatus for Use with the Semimicro Method for Determining Total Lipids in Fish Meal
Authors: Miller Harry , Knobl George M
Published: February 2020

A compact glass extraction apparatus has been designed for use with the semimicro chloroform-methanol extraction method for determining lipids in fish meal. No further handling is required after placing the sample in the extractor; this eliminates manipulative errors and makes the procedure more efficient. Results obtained with the use of this extractor agreed favorably with those from the semimicro method in which a blender was used and with results from AOAC 7.052. It is recommended that the method be studied collaboratively.
Determination of Saccharin in Biological Materials by Gas-Liquid Chromatography
Authors: Daun Robert J
Published: February 2020

A method is described for the quantitative determination of saccharin in urine, feces, blood, and animal tissues. The saccharin is extracted with diethyl ether and methylated with methyl iodide to provide a volatile derivative for gas-liquid chromatography. Higher levels, as found in urine and feces, are determined with a flame ionization detector and lower levels, as in blood and tissues, are analyzed with an electron capture detector after a thin layer chromatographic separation.
Automated Determination of Thiamine (Vitamin B1) in Pharmaceutical Preparations
Authors: Pelletier Omer , Brassard RenÉ
Published: February 2020

The chemical principles used for the determination of thiamine in pharmaceutical preparations by the official USP and AOAC methods were adapted to an automated flowthrough analyzer. The system could analyze 20 samples (including blanks) per hour. Thiamine extracts from 12 different multivitamin preparations were analyzed by one analyst on 5 different days by the automated method and the AOAC method. Both methods yielded comparable values for 10 of the preparations. The thiamine content of 2 preparations containing liver extract was found to be about 9% higher by the automated method than by the AOAC method. Further analysis of other samples of these 2 preparations containing liver extract showed that chromatography on Decalso did not change the results obtained by the automated method, but raised the results obtained by the manual method to a level comparable to the automated method. The AOAC method showed a tendency for a slightly higher reproducibility of assays.
Chemical Analysis of Vitamin D in Concentrates and Its Problems. XII. Analysis of Fat-Soluble Vitamins
Authors: Mulder F J , De Vries E J , Borsje B
Published: February 2020

Details of analytical procedures are given for the analysis of vitamin D concentrates, such as resins, powders, and solutions, all without vitamin A. For the analysis a choice had to be made between the potential vitamin D content (the sum of calciferol (D) and precalciferol (P)) and the actual vitamin D content (calciferol only) in partly isomerized solutions. The biological vitamin D assays can only give the potential vitamin D content when both sample and reference standard solutions are equilibrated simultaneously to the same P ⇋ D ratio. Therefore the biological vitamin D unit should be based on the potential vitamin D content. An important point in the chemical assay of vitamin D in concentrates is the prevention of the oxidation of fat-soluble phenolic antioxidants during saponification. These oxidation products of antioxidants inhibit the color reaction. The colorimetric determination becomes more specific after inactivation of tachysterol by the addition of maleic anhydride. A collaborative test was carried out in 3 laboratories with an oil containing 3 different concentrations of vitamin D. The results of this test have verified the correctness of the analytical procedures.
Gas-Liquid Chromatographic Identification and Determination of Alkanolamines. I. Application to Aerosol Hair Sprays
Authors: Champion Margaree H , Jones John H
Published: February 2020

Alkanolamines, in the absence of water, are converted to the amide ester or triacetate with acetic anhydride-pyridine mixture. The amide ester or triacetate of the alkanolamine is determined by GLC on a column containing diethylene glycol succinate on Chromosorb G. Procedures for determining alkanolamines in various hair sprays are described; recoveries by the proposed procedure were satisfactory. The method developed was applied to the following 4 alkanolamines: 2-amino-2-methyl-1-propanol, 2-amino-2-methyl-1,3-propanediol, 2-amino-2-ethyl-1,3-propanediol, and triisopropanolamine.
Fluorometric Determination of Estradiol Valerate in Sesame Oil or Ethyl Oleate Injectables
Authors: James Theron
Published: February 2020

A fluorometric procedure has been developed for the quantitative determination of estradiol valerate in sesame oil or ethyl oleate. An n-heptane solution of the steroid is purified, using a nitromethane partition column. The purified estradiol valerate is dissolved in alcohol and determined fluorometrically. The method is applicable to a variety of commercial preparations, including estradiol valerate-testosterone enanthate combinations. A total of 14 determinations on 5 different synthetic preparations gave an average recovery of 97.2%. It is recommended that this method be subjected to a collaborative study.
Screening Test for Fluoroacetate in Baits and Biological Samples
Authors: Stahr H M , Clardy Darrell O , Buck William B
Published: February 2020

A simple screening test, based on reaction of the fluoride ion with the ion-selective fluoride electrode, has been developed for fluoroacetate in baits and biological samples. Positive results have been obtained in diagnostic cases. The method is not specific for fluoroacetate, but other fluoride-containing compounds are not likely to be present in the extract. Positive responses to the test should be confirmed as fluoroacetate by another method, such as the official AOAC method or by gas chromatography-mass spectrometry.
Detection of Adulteration of Fruit Juice. I. Characterization of Israel Lemon Juice
Authors: Lifshitz A , Stepak Y
Published: February 2020

A survey of some of the constituents of Israel lemon juice was conducted during the last 4 years. Fifty-eight samples of natural juice, obtained from various sources, were tested for a number of analytical parameters, including a detailed free amino acids analysis. The changes of total soluble solids and acidity as the season progressed were traced. The data were given some statistical treatment.
Detection of Adulteration of Fruit Juice. II. Comparison of Statistical Methods
Authors: Lifshitz A , Stepak Y , Brown M B
Published: February 2020

Following a survey of lemon juice composition, the analytical data are given 2 different statistical treatments. On comparing these treatments, it is found that the specific test based on classical chi-square distribution is more powerful than that based on regression analysis. The analysis of free amino acids provides a method for the detection of adulteration of lemon juice, which is both efficient and difficult to circumvent.
Relative Standard Deviations in Determinations of Amino Acids
Authors: Kwolek W F , CAVINS J F
Published: February 2020

Eighteen references were selected for computation of the relative standard deviation in determinations of amino acids. Cysteine, tryptophan, tyrosine, and methionine were associated with higher relative standard deviations than other amino acids. A mean relative standard deviation of about 8%, ranging from 5.9 to 14.1% depending on the amino acid, was observed between samples independently hydrolyzed. The relative standard deviation between aliquots of the same hydrolysate was 2.7%. Differences in amino acids of 10 to 12% are statistically significant when 2 means, each based on 2 hydrolyses, are compared.
Improvement of the AOAC Kilogram Sample Method for the Isolation of Aflatoxin B1 for Chemical and Biological Confirmation
Authors: Stack Michael , Rodricks J V
Published: February 2020

The official AOAC 1 kg method of isolating aflatoxin B1 for confirmative testing has been improved. An acid alumina column substituted for the 10 g silica gel column eliminates the oily residue which interferes with preparative TLC. Time is saved by processing only enough extract to yield the required amount of aflatoxin. Application of the procedure to aflatoxin-contaminated peanut butter, Brazil nuts, cottonseed meal, and corn resulted in aflatoxin B1 extracts which showed only one spot on TLC plates and gave positive derivative and Bacillus megaterium tests. Aflatoxin-free sample extracts gave negative B. megaterium tests.
Gas Chromatographic Determination of Monitor (O,S-Dimethyl Phosphoramidothioate) Residues in Crops
Authors: Leary J B
Published: February 2020

A gas chromatographic method is described for determining Monitor (0,S-dimethyl phosphoramidothioate) in a variety of crops. After extraction of the sample with ethyl acetate, the solvent is evaporated and an ether solution of the residue is passed through a silica gel column to remove interferences. Monitor is then eluted from the column with acetone and measured by gas chromatography, using a cesium bromide thermionic detector. The majority of standard recovery values ranged between 90 and 100% when samples were fortified at 0.05 to 0.1 ppm.
Improved Method for Determining Benomyl Residues
Authors: Pease H L , Holt R F
Published: February 2020

A fluorometric and colorimetric procedure for determining benomyl residues previously reported has been modified to make it less time-consuming and to now permit analyses of substrates, i.e., citrus, that could not previously be analyzed by the fluorometric method. The sensitivity of the method remains the same, about 0.1 ppm. An alternative procedure to the colorimetric method previously recommended for differentiating between benomyl and other fungicidal benzimidazoles is also described. This alternative procedure is based on fluorometric measurement from both acid and basic media.
Colorimetric Method for the Estimation of Alkaloids in Lobelia and Its Pharmaceutical Preparations
Authors: Karawya M S , Abdel-Wahab S M , Zaki A Y
Published: February 2020

The total alkaloids of lobelia herb and its tincture were estimated colorimetrically after reaction with formaldehyde-sulfuric acid reagent; the results were found to be comparable with those of the 1963 Egyptian Pharmacopoeia method. The alkaloids lobeline, lobelanine, and lobelanidine were estimated individually in the herb and tincture after using the TLC-colorimetric method. The method was found to be sensitive and applicable to pharmaceutical preparations such as lobeline sulfate tablets and lobeline hydrochloride ampuls.
Separation of Three Chlorodibenzo-p-dioxins from Some Polychlorinated Biphenyls by Chromatography on an Aluminum Oxide Column
Authors: Porter Mildred L , Burke Jerry A
Published: February 2020

The separation of 2,3-dichlorodibenzo-p-dioxin, 2,3,7-trichlorodibenzo-p-dioxin, and 2,3,7,8-telrachlorodibenzo-p-dioxin from polychlorinated biphenyls by column chromatography on aluminum oxide is described. Polychlorinated biphenyls were eluted first with 1% methylene chloride-hexane and chlorodioxins were then eluted with 20% methylene chloride-hexane. Recoveries of both polychlorinated biphenyls and chlorodioxins approximated 100%.
Automated Photometric Microbiological Assay for Monensin in Poultry Rations
Authors: Kavanagh F W , Willis Mary
Published: February 2020

A new photometric microbiological assay is described for the coccidiostat monensin in poultry feeds and premixes. The crucial steps in the assay are performed by an automated system. Samples are extracted with acetone and diluted in 50% aqueous acetone to appropriate levels for assay by Streptococcus faecalis ATCC 8043. A special pH 5.2 medium, low in potassium, and polysorbate 80 are used to obtain maximum sensitivity without interference. The range of applicability of the standard curve is 0.10–0.4 μg monensin/ml sample. The assay is free from bias. A relative standard deviation of 1.7% was obtained when 10 feed samples were extracted and assayed 5 times each.
Collaborative Study of Automated Determination of Phosphorus in Meat Products
Authors: Gantenbein Walter M
Published: February 2020

A collaborative study has been conducted on a modification of a previously reported automated method for phosphorus in meat products. Samples were dissolved in 1 + 1 sulfuric acid, cooled to room temperature, and presented to an AutoAnalyzer system. Digestion, dilution, and colorimetric measurement of phosphorus content were performed automatically. Six collaborators participated in the study, analyzing 8 different samples in duplicate. Results of the study were good, with an average range of 0.012% P, average standard deviation of ±0.0047, and average coefficient of variation of 2.32%. The method is recommended for adoption as official first action.
Column Partition Chromatographic Assay for Codeine in Tablets Containing APC
Authors: Siegmund Emil G
Published: February 2020

Codeine is separated from aspirin, phenacetin, and caffeine (APC) on a Celite pH 5.1 buffer column. APC is eluted with ether and determined by AOAC method 36.193–36.198. Codeine is eluted as an ion pair with di-(2- ethylhexyl) phosphoric acid, extracted with 0.LN H2SO4, and determined by UV spectrophotometry. Five commercial samples and 2 synthetic mixtures were analyzed by 9 collaborators for codeine. Recoveries averaged 99.4 ± 1 . 6% and 103±4.0% for the synthetic mixtures containing 16.3 and 1.0 mg/tablet, respectively. The means and standard deviations for commercial tablets were 58.7 ±0.81 mg, 30.4±0.46 mg, 14.5±0.44 mg, 7.54±0.11 mg, and 0.96 ±0.03 mg. The method has been successfully used to analyze all 4 components in 11 commercial samples. The method for codeine is recommended for adoption as official first action.
Column Chromatographic Assay for Sodium Butabarbital in Tablets
Authors: Kaplan Gilbert B , Levine Joseph
Published: February 2020

A column partition chromatographic assay for sodium butabarbital tablets is described. The method was collaboratively studied with a composite of commercial tablets and a preparation of known composition as samples. The average recovery for both samples was 99.3%; the standard deviations were 1.4 and 1.1%, respectively. It is recommended that the method be adopted as official first action.
Collaborative Study of Assay for Benzthiazide and Hydrochlorothiazide in Pharmaceuticals
Authors: Fazzari F Raymond
Published: February 2020

A method for the determination of benzthiazide and hydrochlorothiazide in pharmaceuticals was collaboratively studied by 10 analysts. The method is a previously published column partition chromatographic technique with a spectrophotometric determination. The average per cent recovered and standard deviation for preparations of benzthiazide and hydrochlorothiazide were, respectively, 99.5±1.35 and 99.6±1.22. It is recommended that the method be adopted as official first action for benzthiazide, hydrochlorothiazide, and hydroflumethiazide
Gas-Liquid Chromatographic Determination of Paraldehyde in Paraldehyde Elixir
Authors: Lampkin William T
Published: February 2020

A collaborative study was conducted on a GLC method for determining paraldehyde in pharmaceutical preparations of paraldehyde elixirs. Eleven collaborating laboratories analyzed 2 unknown paraldehyde solutions and a solution of known paraldehyde concentration. Recoveries of 15–25% paraldehyde solutions averaged 98.5% with a coefficient of variation of about 2%. The method consists of diluting a sample aliquot to a definite volume and determining the paraldehyde content by GLC, using a flame ionization detector and a 6’ × 4 mm coiled glass column packed with 80–100 mesh Diatoport S coated with 2% HIEFF-8BP (cyclohexane dimethanol succinate) plus 20% Carbowax 20M. The internal standard technique was used for calculation. It is recommended that the method be adopted as official first action.
Automated Fluorometric Analysis of Reserpine and Syrosingopine Tablets, Using a Vanadium Pentoxide Reagent
Authors: Urbányi Tibor , Stober Henry
Published: February 2020

Semiautomated methods suitable for the determination of reserpine and related compounds in tablet formulations have been reported. The basis of these methods of determination is the classical nitrite procedure. The need of a more practical, completely automated system with less manipulation resulted in the development of a fluorometric method, using vanadium pentoxide as a reagent. This method is rapid, precise, and sensitive enough for formulations containing as little as 0.1 mg reserpine or similar compounds per unit dosage. The parameters influencing the sensitivity, precision, and speed of the new fluorometric determination are described in detail.
Determination of Dienestrol in Pharmaceuticals
Authors: Graham Joseph H , Banes Daniel , Proctor Joseph B
Published: February 2020

A highly specific, rapid, and sensitive assay procedure for dienestrol in pharmaceuticals has been developed. Dienestrol is separated from excipient matter and other drugs present in the dosage form by column chromatography and determined spectrophotometrically as a substituted indene, formed by acidinduced isomerization of dienestrol. The procedure is directly applicable to creams and individual tablets.
Chemical Composition of Mexican Pineapple
Authors: Boland Frederick E , Blomquist Victor H , Estrin Ben
Published: February 2020

Authentic data are presented on the chemical composition of Mexican pineapple. Samples were analyzed for total soluble solids, ash, K20, P2O5, invert sugar, sucrose, protein, acidity (as anhydrous citric acid), insoluble solids, Na20, and amino acids. The data are presented for 18 samples (10 canned and 9 fresh).
Turbidimetric Evaluation of Bacterial Culture Resistance in Disinfectant Testing
Authors: Chen John H S , Ortenzio L F
Published: February 2020

A simple turbidimetric method has been developed for determining the degree of phenol resistance of cultures used for disinfectant testing. Net transmission values are used to assess t h e degree of resistance; these are based on t h e measurement of the total amount of light scattered by the bacterial growth i n the AOAC broth medium without interfering turbidity of the dissolved ingredients. A decrease in the net transmission value corresponds to a decrease in phenol resistance; the converse is also true . The transmission values obtained in a 10 month study of a total of 77 weekly r and om samples of AOAC nutrient broth media blanks showed no substantial differences among the broth media tested by the turbidimetric method. Net transmission values were obtained for 71 broth cultures of Salmonella choleraesuis, 74 of Staphylococcus aureus, and 78 of Pseudomonas aeruginosa having the same required resistance against phenol. These values, which fell within a wider range than would be expected, are given. The effect of the number of 10-carrier-soakings on the net transmission value and equivalent phenol resistance of the cultures was determined for 60 broth cultures of the 3 test organisms named above. Soaking wet cylinder carriers in a given volume of test cultures used for the AOAC use-dilution test directly reduced the net transmission value and equivalently decreased the phenol resistance of the cultures. The turbidimetric method has proven experimentally satisfactory i n several hundred determinations and in selecting test cultures of uniform quality for disinfectant testing.
Simplified Method for the Determination of Propionates in Bread: Isolation by Micro diffusion
Authors: Karasz A B , Hallenbeck W
Published: February 2020

In the method presented, propionic acid is isolated from bread by microdiffusion at an elevated temperature in preparation for determination by gas-liquid chromatography. This isolation procedure is simple, utilizes inexpensive equipment, and permits the simultaneous processing of a large number of samplef. Results obtained by microdiffusion agree closely with those obtained by steam distillation according to AOAC 14.089. After isolation by either microdiffusion or steam distillation, propionic acid in all samples was determined by gas-liquid chromatography as described in 18.038 rather than partition column chromatography as described in 14.090-14.091. An average of 98% of the propionic acid found by using steam distillation was found by using the microdiffusion technique.
Structure of Ethylene Thiuram Monosulfide
Authors: Benson W R , Ross R D , Chen Jo-Yun T , Barron R P , Mastbrook D
Published: February 2020

A new structure is proposed for ethylene thiuram monosulfide based primarily on mass, Raman, and nuclear magnetic resonance spectral data. Data in the older literature, for the most part, are consistent with both the old and new structures; however, new data are consistent only with the new structure.
Notes on Microanalytical Techniques in the Analysis of Foods for Extraneous Materials. Part II.
Authors: Brickey Paris M , Gecan John S , Thrasher Joel J , Vazquez Alberto W
Published: February 2020

The second paper in this series describes some useful and time-saving microanalytical techniques. Topics discussed include sealing of glass bottles, vial closures, and petri dishes, collaborative evaluation forms, permanent identification of metal and glass sample containers, shipping containers for breakable collaborative sample containers, new defatting procedure prior to light filth analysis, new filtration procedures, collection of live mites and insects from bulk food samples, and preparation and handling of microscopic exhibits of insect fragments and hairs.
Collaborative Study of a New Method for the Extraction of Light Filth from Soy Flour
Authors: Dent Russell G , Brunson Michael
Published: February 2020

Collaborative results are presented for a proposed method for light filth extraction from soy flour. The method involves dispersion in saturated NaCl and isopropanol, wet sieving, and extraction with hot mineral oil from alcohol in a percolator. Average per cent recoveries of spiked elytral fragments and rodent hairs were 88.2 and 65.5, respectively, by the proposed method compared to 64.5 and 56, respectively, by official procedure 40.053. The existing procedure for soy flour is time-consuming because it requires an overnight enzymatic digestion and a hazardous petroleum ether defatting step. The proposed method eliminates both of these steps arid the analysis can be completed in 1–2 hr. It is recommended that the method be adopted as official first action to replace 40.053.
Collaborative Study of a Method for the Extraction of Light Filth from Wheat Gluten
Authors: Brickey Paris M , Gecan John S
Published: February 2020

In the method described for the extraction of light filth from wheat gluten, the product is dispersed in an alcohol-acid solution and then boiled, with stirring. After boiling, the product is trapped off with mineral oil from an aqueous solution of 40% isopropanol in a Wildman trap flask. In the collaborative study reproducible counts and high recoveries of insect fragments and rodent hairs were obtained and the method was demonstrated to be rapid and easy to perform. The method is recommended for adoption as official first action.
Method for Preparing Garlic Powder (Ground Dehydrated Garlic Bulbs) for Examination by the Howard Mold Count Method
Authors: Parran Hamilton M , Douglas Ruth G , Eisenberg William V
Published: February 2020

The official first action method for rot (based on mold count) of ground capsicums, 40.112, was applied to garlic powder. Although there is some variation in the collaborators’ mold counts, the method for preparation for mold count, when used by experienced microanalysts, is satisfactory for detecting the use of decomposed garlic bulbs in the preparation of the product. It is recommended that method 40.112 be adopted as official first action for determining rot in garlic powder.