bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative Study of Methods for the Extraction of Eleven Organophosphorus Pesticide Residues in Rice
Authors: Aoki Yoichi , Takeda Mitsuharu , Uchiyama Mitsuru
Published: February 2020

Several extraction methods are compared for the simultaneous analysis of organophosphorus pesticides in unpolished rice. Four stationary phases were used for the subsequent gas-liquid chromatographic (GLC) determination of the selected pesticides. Using 3 different GLC columns, 11 pesticides were completely separated and identified. The efficiency of the cleanup and the sensitivity of the analytical method were evaluated by using powdered unpolished rice samples fortified with the pesticides and also wheat and dried bean samples. Average recoveries ranged from 74.7% for disulfoton to 97.4% for malathion in unpolished rice and from 68.1% for disulfoton to 108.3% for malathion in other crops. The method described is applicable to the analysis of selected organophosphorus pesticide residues in unpolished rice, wheat, buckwheat, and dried beans.
Gas-Liquid Chromatographic Determination of Capsaicin
Authors: DiCecco Joseph J
Published: February 2020

A simple and accurate method has been developed for the quantitative determination of capsaicin in capsicum spices and their oleoresins. Capsaicin is extracted with acetone and separated from interfering substances, using an activated alumina column. The column is first eluted with acetone, and then the capsaicin is eluted with acetone-methanol-water (75+25+2). The capsaicin is quantitated by gas-liquid chromatography, using a Carbowax 20M-Teflon column and piperine as an internal standard. Results can be calculated as per cent capsaicin or Scoville units. Recovery of added capsaicin averaged 101%.
Collaborative Study of a Screening Method for the Detection of Aflatoxins in Mixed Feeds, Other Agricultural Products, and Foods
Authors: Romer Thomas R , Campbell Alfred D
Published: February 2020

A screening method for aflatoxins was collaboratively tested on 11 different agricultural and food products: white and yellow corn, peanuts, peanut butter, pistachio nuts, peanut meal, cottonseed meal, chicken, pig, and turkey starter rations, and dairy cattle feed. The method involves a rapid extraction and cleanup procedure followed by the detection of total aflatoxins (B1 + B2 + G1 + G2) as a fluorescent band on the Florisil layer of a Velasco-type minicolumn. The results of 32 collaborators from 10 different countries are presented. Samples containing 0, 5, 10, 15, 20, and 25 μg aflatoxins/kg were analyzed. Eighty-four per cent of the negative samples and 89% of the samples containing 10–25 μg total aflatoxins/kg were correctly identified. This method has been adopted as official first action for the detection of aflatoxins in corn, peanuts, peanut butter, peanut meal, cottonseed meal, mixed feeds, and pistachio nuts.
Detection of Volatile Solvents in Gastric Contents by Gas Phase Infrared Spectrophotometry
Authors: Fastlich Eugene
Published: February 2020

A standard procedure for the identification of volatile solvents in the gas phase by infrared spectrophotometry has been modified and applied to the analysis of gastric contents. A 10 ml sample of the vapor from the gastric aspirate is removed with a hypodermic syringe, injected into a gas cell at reduced pressure, and scanned on a spectrophotometer from 2.5 to 15 nm. The sample is then identified by comparison with known reference spectra. Solvent concentrations can be estimated by comparing the ratios of the major peaks.
Collaborative Study of an Automated Method for the Determination of Crude Protein in Animal Feeds
Authors: Noel Rodney J
Published: February 2020

An automated macro Kjeldahl instrument determines per cent protein at the rate of 20 samples/hr. The methodology involved is similar to the present official final action Kjeldahl method, sec. 7.016. The 2 methods were compared in a collaborative study. Sixteen animal feeds, 4 meats, tryptophan, ammonium dihydrogen phosphate NBS standard, and ammonium sulfate primary standard were analyzed by the participating laboratories. The data were treated statistically and the results showed good agreement between the 2 methods. The automated method has been adopted as official first action for the determination of crude protein in feeds, plants, and cereal foods.
Collaborative Study of Effect of Light on Cadmium and Lead Leaching from Ceramic Glazes
Authors: Krinitz Benjamin , Holak Walter
Published: February 2020

A limited interlaboratory study was carried out to determine the effect of lighting conditions on the release of cadmium from ceramic glazes by 4% acetic acid. Cadmium release increased with increased exposure to light. Further interlaboratory study on plates manufactured under controlled conditions showed that if temperature, intensity of illumination, and time of exposure are specified, reproducible results for leaching of both lead and cadmium can be obtained. A modification of the official AOAC method, 25.031–25.034, to increase sensitivity was collaboratively studied by 8 laboratories. Each received 6 solutions of lead in 4% acetic acid (3 sets of blind duplicates at the 0.1, 0.5, and 0.8 μg/ml levels) plus a reagent blank. Average recoveries were 0.1006, 0.5056, and 0.8194 μg/ml, respectively, with coefficients of variation of 11.4, 3.3, and 2.8%, respectively. The proposed modification is simple, rapid, and accurate. The modification has been adopted as official first action, and a parameter for exposure to light during extraction has been included in the method.
Partition Chromatographic Separation of Pesticide Residues from Fats
Authors: Dale William E , Miles James W
Published: February 2020

A simple, rapid, and efficient partitioning column consisting of acetonitrile on Florisil has been developed for the separation of pesticides from fish, beef, and butter fat. The efficiency of the cleanup column is between 97 and 100%. Nine pesticides having partition coefficients between n-hexane and acetonitrile of ≤0.05 were satisfactorily separated from fat with good recoveries. When the column was used to clean up temephos in a fish extract, 99.91% of the fat was eluted with 20 ml n-hexane with no loss of the pesticide.
Determination of Quinomethionate (6-Methylquinoline-2,3-diyldithiocarbonate) Residues in Crops by In Situ Fluorometry
Authors: Francoeur Yves , Mallet Victorin
Published: February 2020

A simple method is described for the quantitative determination of quinomethionate (6-methylquinoline-2,3-diyldithiocarbonate) in crops. The pesticide residue is extracted with acetonitrile and partitioned in petroleum ether. After separation from the co-extractives by thin layer chromatography (TLC), the fluorescence is measured directly on a silica gel TLC plate. An average of 89% recovery is obtained at the 0.05 ppm level in apples, peaches, pears, and tomatoes.
An Indirect Determination of Biuret in Mixed Fertilizers and Urea by Atomic Absorption Spectrophotometry
Authors: Woodis Terry C , Hunter G Bradley , Johnson Frank J
Published: February 2020

An indirect method for determining biuret in mixed fertilizers and urea has been developed. An alcoholic solution of biuret and copper is treated with a strong base to form a biuret-copper complex and to precipitate the excess copper. After separation of the precipitate, the complexed copper in solution is determined by atomic absorption spectrophotometry. Even though a stoichiometric ratio did not exist, a linear relationship between copper and biuret was obtained and was utilized for the determination of biuret. The proposed method is accurate and proved rugged for the range of biuret normally found in mixed fertilizers and urea when subjected to Youden’s ruggedness test.
Procedures for Cooking Seafood Products
Authors: King Frederick J
Published: February 2020

Standardized methods of heating are described to prepare seafood products for grading by flavor and odor. Previous experience and current methodology are given for baking, boil-in-bag, deep fat frying, and steaming procedures. The techniques have been accepted as procedures.
4,4′-(Diazoamino)-bis(5-methoxy-2-methylbenzenesulfonic Acid): Preparation and Determination in FD&C Red No. 40
Authors: Bailey John E , Cox Elizabeth A
Published: February 2020

4,4′-(Diazoamino)-bis(5-methoxy-2-methylbenzenesulfonic acid) (CSAT) has been found in samples of FD&C Red No. 40 submitted for certification, using high-pressure liquid chromatography (HPLC). CSAT is synthesized by diazotizing cresidine sulfonic acid (CSA) and coupling the diazonium salt with undiazotized CSA in the presence of sodium acetate. A method for quantitative determination of CSAT in FD&C Red No. 40, using HPLC and an untested method of correcting for interfering compounds, is presented.
Collaborative Study of an Enzymatic Digestion Method for the Isolation of Light Filth from Ground Beef or Hamburger
Authors: Alioto Phillip , Andreas Mary
Published: February 2020

Collaborative results are presented for a proposed method for light filth extraction from ground beef or hamburger. The method involves enzymatic digestion, wet sieving, and extraction with light mineral oil from 40% isopropanol. Recoveries are good and filter papers are clean. This method has been adopted as official first action.
Analysis of Bromide Ion in Wine by Ion Selective Electrode
Authors: Graf James E , Vaughn Troy E , Kipp William H
Published: February 2020

The use of the bromide ion selective electrode for the determination of bromide ion in wine has been found to be rapid and reliable. The method has been used for still wines and carbonated wines and is applicable to all wines regardless of their country of origin. The method consists of treating a 50 ml aliquot of wine with 2 ml each of 3.75M H3PO4, saturated KNO3, and 1M CuSO4. After 10 min the electrodes are immersed in the samples and a millivolt reading is obtained. One hundred μl 500 ppm bromide ion standard is added and the millivolt reading is taken. Bromide ion concentration in the wine = (CΔ × 1)/((antilog ΔE/S) − 1) where CΔ = 1, ΔE = the change in potential expressed in millivolts, and S = the electrode slope.
Identification of Some Analogs of the Hallucinogen Phencyclidine
Authors: Bailey Keith , Gagné Denise R , Pike Richard K
Published: February 2020

The drugs 1-[1-(2-thienyl)cyclohexyl]piperidine, 1-[1-(2-thienyl) cyclohexyl] morpholine, 1-[1-(2-thienyl)cyclohexyl] pyrrolidine, 1-(1-phenylcyclohexyl) morpholine, and 1-(1-phenylcyclohexyl) pyrrolidine are identified by spectroscopic techniques. The ultraviolet and proton magnetic resonance spectra of analogs are similar, but mass and infrared spectra are distinctly different, and reference spectra are provided. Gas-liquid and thin layer chromatographic systems for the analysis are discussed.
Collaborative Study of a Column Chromatographic Method for Bendroflumethiazide and Cyclothiazide
Authors: Fazzari Frank R
Published: February 2020

Bendroflumethiazide and cyclothiazide are eluted from a sodium carbonate column with chloroform-acetic acid (98+2) and are measured directly by ultraviolet spectrophotometry. The method was collaboratively studied by 8 analysts. The average per cent recovery and standard deviations for simulated mixes of bendroflumethiazide and cyclothiazide were 99.61±0.94 and 98.85±3.28, respectively. For commercial preparations the respective values were 99.52±0.78 and 99.3±1.97. The method has been adopted as official first action for the determination of bendroflumethiazide.
Determination of Total Nitrogen in Plant Tissue, Using a Block Digestor
Authors: Isaac Robert A , Johnson William C
Published: February 2020

The determination of total nitrogen in plant tissue using a Technicon BD-40 digestor provided one of the best analytical tools for Kjeldahl digestion. The method is rapid and precise and utilizes the minimum laboratory space for such operations. The ammonia found is determined using the automated continuous flow methodology of an AutoAnalyzer. Up to 300 samples/day may be analyzed with a single system. Recovery of added nitrogen was 100.9±4.1%. Comparison with AOAC method 2.049 gave an average difference of 0.02% nitrogen for 8 plant tissues.
Quantitation of o- and p-Sulfamoylbenzoic Acids in Commercial Saccharin by High-Performance Liquid Chromatography
Authors: Nelson James J
Published: February 2020

Quantitation of o- and p-sulfamoylbenzoic acid residues in saccharin and its sodium salt is achieved by a method comprising methanolic extraction and high-performance ion exchange chromatography. A commercially available anion exchange column was employed with an aqueous buffered (pH 9.2) mobile phase. As little as 80 ppm of the ortho-isomer and 25 ppm of the para-isomer can be accurately determined. The levels of detectability (2 times noise) are estimated as 8 ppm (0.16 μg on column) and 2.5 ppm (0.05 μg on column), respectively. Recoveries from saccharin ranged from 92.7 to 96.5% (ortho) and from 92.2 to 103.3% (para). Recoveries from the sodium salt ranged from 93.1 to 104.4% (ortho) and from 93.5 to 97.8% (para). Of 9 other potential saccharin impurities tested separately, only one was found to interfere slightly in the chromatographic part of the procedure.
Gas-Liquid Chromatographic Determination of Famphur and Its Oxygen Analog in Tissues of Reindeer and Cattle
Authors: Ivey Marcellus C
Published: February 2020

A gas chromatograph equipped with a flame photometric detector operating in the phosphorus mode provided a sensitive method for determining residues of famphur, O,O-dimethyl O-[p-(dimethylsulfamoyl)phenyl]phosphorothioate, and its oxygen analog in reindeer and cattle tissues. With extraction and cleanup, 0.025 ppm famphur and 0.06 ppm oxygen analog could be detected in the body tissues. Recoveries of 73–100% were obtained from fat, muscle, liver, and kidney.
Collaborative Study of the Colorimetric Determination of Nitrate and Nitrite in Cheese
Authors: Hamilton James E
Published: February 2020

A quantitative colorimetric method for the determination of nitrate and nitrite in cheese has been subjected to collaborative study. The method includes clarification of an aqueous extract of cheese with zinc hydroxide, reduction of nitrate to nitrite via a spongy cadmium column (the nitrite originally present is unaltered), diazotization of sulfanilic acid with the nitrite, and coupling with 1-naphthylamine hydrochloride to form a pink azo dye whose absorbance is measured at 522 nm. The spectrophotometric responses are compared to a standard curve. In samples containing both nitrate and nitrite, nitrate is determined by difference. A standard deviation of 5.5 was obtained (5 of 6 collaborators) when a cheese sample spiked with 276 ppm sodium nitrate was analyzed by the method. The method has been adopted as official first action.
Correction of Refractometer Sucrose Readings for Citric Acid Content in Frozen Concentrate for Lemonade
Authors: Yeatman John N , Senzel Alan J , Springer Janet A
Published: February 2020

Computer-generated regression equations to express citric acid corrections for refractometer sucrose readings in frozen concentrate for lemonade were developed from experimentally determined values for °Brix, soluble solids, and citric acid content. These equations have been included in a method for the calculation of soluble solids in frozen concentrate for lemonade. The method has been adopted as official first action.
Determination of Melengestrol Acetate in Bovine Tissue: Collaborative Study
Authors: Krzeminski Leo F , Geng Shu , Cox Byron L
Published: February 2020

Seven laboratories collaboratively studied a method for the assay of melengestrol acetate at the 0, 10, and 20 ppb levels in bovine fat, liver, muscle, and kidney. The study included fortification of tissue by each laboratory and analysis of fat samples taken from treated heifers which had endogenous levels of 0, 10, and 20 ppb melengestrol acetate. The multistep cleanup procedure used included extraction, solvent partition, column chromatography, and electron capture gas-liquid chromatographic determination. Results of the study for muscle, liver, kidney, and fat showed that the method gave satisfactory recoveries and accuracy. In fat, the most critical tissue, recovery was >93%. A statistical comparison of the results reported for fat tissue from treated heifers demonstrated that 5 of the 7 laboratories obtained similar results. The results produced by the method can be expected to be repeatable within and among laboratories. On the basis of the collaborative results the method has been adopted as official first action.
Turbidimetric and Diffusion Assay of Bacitracin in Feeds
Authors: Ragheb Hussein S , Black Lisa , Graham Sherrie
Published: February 2020

A manual turbidimetric method for determining zinc or methylene disalicylate bacitracin in feeds was developed. When zinc ions (10−4M) were added to the medium and the phosphate ion concentration in standard solutions was decreased to 1%, the median response of Streptococcus faecalis was about 0.038 unit. Feeds analyzed by the turbidimetric assay should be prewashed with petroleum ether and extracted with pyridine as in 42.204. Zinc bacitracin standards added to swine and broiler rations were recovered at 93.1–102.6% by the turbidimetric method. Excellent agreement between the manual turbidimetric method and the plate assay was also obtained for finished feeds containing the zinc or methylene disalicylate salt of the antibiotic. The turbidimetric method appears to have high accuracy and precision. It is more rapid and less costly than the plate assay.
Modified Assay Medium for the Turbidimetric Assay of Chlortetracycline in Feeds
Authors: Ragheb Hussein S
Published: February 2020

In previous experiments, the turbidimetric method for determining chlortetracycline-HCI (CTC-HCl) in feeds showed lower recovery than the AOAC plate method. Although the addition of vitamins to the turbidimetric medium improved results, values by the turbidimetric method remained about 10% lower than by the plate method. A modified (1.7 × the weight recommended by the manufacturer) turbidimetric assay medium decreased assay sensitivity but did not significantly change the slope of S. aureus response to CTC-HCl. There was no evidence that vitamin fortification of the modified medium had any significant effect on the growth rate of test organism. Examination of about 100 samples of commercial feeds containing CTC-HCl showed excellent agreement in results between the turbidimetric and plate methods.
Determination of Hexachloro-1,3-butadiene in Spinach, Eggs, Fish, and Milk by Electron Capture Gas-Liquid Chromatography
Authors: Yurawecz Martin P , Dreifuss Peter A , Kamps Laverne R
Published: February 2020

Hexachloro-1,3-butadiene (HCBD), a waste product formed in the manufacture of perchloroethylene and trichloroethylene, has been found in fish from the lower Mississippi River basin. The AOAC official method for organochlorine pesticide residues in fatty and nonfatty foods has been modified for the determination of HCBD residues in selected food commodities. Acetonitrile extracts of nonfatty foods, or the combined acetonitrile extracts obtained in acetonitrile-petroleum ether partitioning of fat isolated from fatty foods, are diluted with water and extracted with petroleum ether. The petroleum ether extracts are chromatographed on Florisil and HCBD is eluted with petroleum ether. The eluate is analyzed by gas-liquid chromatography with an electron capture detector. Average recoveries of HCBD from fortified samples of fatty and nonfatty foods were greater than 90% in the interlaboratory trials of the method.
Survey for Hexachloro-1,3-butadiene in Fish, Eggs, Milk, and Vegetables
Authors: Yip George
Published: February 2020

Eighty-four samples (fish, milk, eggs, vegetables) were collected from within a 25 mile radius of 10 perchloroethylene or trichloroethylene manufacturing plant sites and analyzed for hexachloro-1,3-butadiene (HCBD) by a gas chromatographic method. Residues of HCBD were found mainly in freshwater fish caught in the lower Mississippi River. The levels ranged from 0.01 to 1.2 ppm. Two of the 20 saltwater fish contained residues of 0.01 and 0.02 ppm. No HCBD residues were found in eggs and vegetables. One of 20 milk samples contained 1.32 ppm HCBD.
Quantitative Determination of 4,4′-(Diazoamino)-bis (5-methoxy-2-methylbenzenesulfonic Acid) in FD&C Red No. 40 by Ion Exchange Chromatography
Authors: Fratz D Douglas
Published: February 2020

An ion exchange chromatographic procedure is presented which separates 4,4′-(diazoamino)-bis(5-methoxy-2-methylbenzenesulfonic acid) (DMMA) from FD&C Red No. 40. The DMMA is determined spectrophotometrically. Recoveries of DMMA added to FD&C Red No. 40 at levels of 0.05 to 0.20% ranged from 90 to 110%. DMMA was found in commercial samples of FD&C Red No. 40 in amounts ranging from <0.02 to 0.11%.
Phosphorus Pentoxide as a Drying Agent for Bacterial Culture Extracts Analyzed by Gas-Liquid Chromatography
Authors: Finne Gunnar , Matches Jack R
Published: February 2020

The procedure for gas chromatographic analysis of metabolic products of microbial fermentation includes solvent extraction of the aqueous growth media, drying of the extract, and direct chromatographic analysis of the solvent. In this study, 2 drying agents, magnesium sulfate and phosphorus pentoxide, were compared. Both were effective in removing water; however, phosphorus pentoxide removed water more completely and at a faster rate than magnesium sulfate. When a thermal conductivity detector is used, it is important to completely remove water from the solvent to prevent interference with volatile acids and alcohols. When water is present, short-chain alcohols (C2–C5) are eluted together with the water, causing peak overlap and shoulder separations. Phosphorus pentoxide quickly and effectively removed water so that a baseline was established following the solvent front on the chromatogram. The use of phosphorus pentoxide is particularly advantageous for identification or fermentation studies on Clostridium and Propionibacterium when rapid identification is desired or when large numbers of cultures are to be tested.
Collaborative Study of an Improved Method for the Enumeration and Confirmation of Clostridium perfringens in Foods
Authors: Harmon Stanley M
Published: February 2020

A collaborative study was conducted in 10 laboratories to evaluate the performance of a new method for the enumeration of vegetative cells of Clostridium perfringens in foods. Results obtained by the new method were compared with results from the official first action method, 46.049–46.053. Per cent recoveries of 4 C. perfringens strains from inoculated roast beef samples were higher and more consistent in tryptose-sulfite-cycloserine (TSC) agar with or without added egg yolk than in sulfitepolymyxin-sulfadiazine (SPS) agar, specified in the official first action method. The confirmatory technique utilized in the new method was also found to be more reliable than the technique described in the official first action method. Based on the collaborative results, the new method with TSC agar for enumeration and a modified motility-nitrate medium together with a lactose-gelatin medium for confirmation of C. perfringens has been adopted as official first action to replace 46.049–46.053.
Gas-Liquid Chromatographic Analysis of Ethephon and Fenoprop Residues in Apples and Their Decline Before and After Harvest
Authors: Cochrane William P , Greenhalgh Roy , Looney Norman E
Published: February 2020

Ethephon (2-chlorocthylphosphonic acid) and fenoprop (2-(2,4,5-trichlorophenoxy) propionic acid) may be determined in the same apple sample. After extraction with methanol, 2 separate methylation procedures were required to quantitatively convert each compound. Ethephon was esterified with diazomethane and analyzed by a flame photometric detector in the P-mode. Fenoprop was esterified with boron trifluoride/methanol and analyzed by electron capture gas chromatography. Average recoveries were about 95% at 0.05 ppm for both compounds. The limit of detection was 0.05 ppm for ethephon and 0.01 ppm for fenoprop in a 1 g sample. The persistence of both compounds before and after harvest was studied. Ethephon and fenoprop were applied simultaneously to apple trees at the recommended concentrations of 300 and 20 ppm, respectively. Ethephon residues averaged 1.6, 0.75, and 0.4 ppm at 2 hr, 10 days, and after washing at 13 days, respectively. The corresponding fenoprop residues were 0.70, 0.025, and 0.024 ppm.
Thin Layer Chromatography of Parathion as Paraoxon with Cholinesterase Inhibition Detection
Authors: Nanda Kumar Nanguneri V , Visweswariah Krishnamurthy , Majumder Suvendu K
Published: February 2020

A simple, sensitive, and rapid method is described for the quantitative estimation of ng amounts of parathion (O,O-diethyl O-p-nitrophenyl phosphorothioate) as paraoxon (O,O-diethyl O-p-nitrophenyl phosphate) on thin layer chromatograms. Paraoxon is detected by inhibition, using p-nitrobenzenediazonium fluoroborate as the chromogenic reagent. This chromogenic reagent is more sensitive than Fast Blue B or indoxyl acetate; 0.1 ng may be detected and amounts from 5 to 50 ng may be estimated. The method is a viable alternative to gas chromatographic analysis for parathion.
Methods of Analysis Approved by the Codex Alimentarms Commission. I. Acid Value
Authors: Horwitz William
Published: February 2020

Numerous variations exist for determining the acidity of fats and oils by titration. A Youden ruggedness test was performed, using extreme conditions existing in the methods, endorsed by various international organizations: aqueous and alcoholic standard alkali, 5 or 56 g sample, 50 or 150 ml alcohol or alcohol-ether solvent, titration at room temperature or 60°C with 2 ml or 8 drops of phenolphthalein indicator, to the first color change or to a pink persisting for 60 sec. The titration method was found to be extremely rugged at the 1 % oleic acid level with none of the variables influencing the result. At the 0.15% level, only the sample size affected the result.
Determination of Zearalenone in Corn: Collaborative Study
Authors: Shotwell Odette L , Goulden Marion L , Bennett Glenn A
Published: February 2020

Corn samples spiked at levels of 100, 300, 1000, and 2000 μg zearalenone/kg were sent to 22 collaborators for analysis by the Eppley method. All samples were yellow corn except one white corn sample spiked at 2000 μg/kg. Results from 16 collaborators were statistically analyzed. Only 4 of 16 collaborators detected zearalenone in the sample containing 100 μg/kg, but 11 detected the toxin in the sample containing 300 μg/kg. Average recoveries from all samples were 129% at 300 μg/kg, 101% at 1000 μg/kg, and 88% at 2000 μg/kg. The between-laboratory coefficients of variation were 53.0% at 300 μg/kg, 38.2% at 1000 μg/kg, and 27.0% at 2000 μg/kg. Five naturally contaminated corn samples, one in triplicate, were also provided. The mean level of zearalenone in the naturally contaminated samples ranged from 431 to 7622 μg/kg. The mean coefficient of variation for all samples was 40.5%. Two collaborators measured quantities of zearalenone on thin layer chromatographic plates densitometrically. Their results were not included in the statistical analysis, but the results indicated that densitometric measurement, given proper dilutions of solutions, could be used. The method has been adopted as official first action.
Spectrophotometric Determination of Allylisothiocyanate in Mustard Seed Oil
Authors: Devani Muljibhai B , Shishoo Chamanlal J , Dadia Bharti K
Published: February 2020

Allylisothiocyanate is determined spectrophotometrically after reaction with 2,3-dichloro-1,4-naphthoquinone. For pure samples, the color intensity is proportional to allylisothiocyanate content in the range 0.8–3.0 mg/ml reaction mixture. A modified procedure is used to estimate allylisothiocyanate content of mustard seed oil. The reaction is linear for allylisothiocyanate concentrations in the range 40–240 μg/ml reaction mixture. Two mustard seed oil samples contained 0.995 ± 0.020 and 0.981 ± 0.019% allylisothiocyanate.
Biological Parameters and the Acute LD50 Test
Authors: Sperling Frederick , McLaughlin Joseph L
Published: February 2020

The acute LD50 is an inadequate index of toxicity because the catastrophe of death obscures the mechanisms and sites of action. Thus, nonlethal toxicity is not evaluated, and the LD50 is not extrapolated to the possible effects of low level exposures for long periods of time. Collaborative studies should be undertaken which would develop methods to reasonably permit such evaluation and extrapolation.
Estimation of Milligram and Submilligram Amounts of Busan Fungicide
Authors: Miller Vernon L , Csonka Elizabeth , Gould Charles J
Published: February 2020

A procedure is described for the estimation of Busan 72 ((2-thiocyanomethylthio)benzothiazole) in the range of 0.01–1.0 mg/ml. An aqueous suspension of the material is heated with dilute sodium hydroxide, cooled, and treated with copper ion. The insoluble reaction product is filtered, and excess copper is determined by using a pyridine-thiocyanate procedure. Analysis may be completed by either spectrophotometry or comparison with described artificial standards.
Collaborative Study of the Determination of Color in White Wines Dust and Powder Formulations
Authors: McDermott William H
Published: February 2020

Some 10% and lower guarantee carbaryl dusts cannot be quantitatively extracted by shaking with chloroform as specified in the official first action infrared method for carbaryl formulations, 6.293–6.295. The official method has been compared in a collaborative study with an alternative method in which a simple rotator has replaced the wrist-action shaking machine and a solution of 10% (v/v) methanol in chloroform has replaced chloroform. The results indicate the alternative method is superior to the official method when applied to difficult-to-extract formulations and equal to it for all other formulations. The mixed solvent-rotator alternative method has been adopted as official first action to replace the present method for the carbaryl analysis of carbaryl formulations.