bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multiresidue Analysis of Fourteen Organophosphorus Pesticides in Natural Waters
Authors: Ripley Brian D , Wilkinson Robert J , Chau Alfred S Y 
Published: February 2020

Abstract
A method is described for the determination of 14 organophosphorus pesticides in natural waters at less than μg/L (ppb) concentrations. Two extraction methods are described: the vortex stirring method for water that forms light emulsions and the separatory funnel method for water that forms heavy emulsions during extraction. Extraction recoveries were 95– 110% for all compounds except crufornate (115%). Two concentration methods are also described with recoveries of 95–116%. Compounds were determined by isothermal gas chromatography using a flame photometric detector that is quantitatively sensitive to phosphorus. The sensitivity of the method for most of the 14 compounds was 0.01 ppb, using 1 L water. Retention times of all compounds were constant during isothermal analysis. Possible losses due to storage were also examined.
Preparation, Gas Chromatographic Behavior, and Spectroscopic Properties of Hydroxylated Chlorobiphenyls
Authors: Hutzinger Otto , Safe Steve , Zitko Vladimir 
Published: February 2020

Abstract
Some useful methods for the preparation of chlorobiphenylols have been investigated. Twenty monohydroxy and dihydroxy derivatives of chlorobiphenyls are described; 10 are new compounds and several are known metabolic products from animals or microorganisms. The relationship between structure of the chlorobiphenylols and gas chromatographic retention time as well as electron capture detector response, including those of derivatives, has been examined. The ultraviolet, fluorescence, and mass spectra of these hydroxylated derivatives have also been examined with a view towards analysis and structure elucidation of metabolites.
Liquid Chromatographic Method for Determination of Patulin in Apple Juice
Authors: Ware George M , Thorpe Charles W , Pohland Albert E 
Published: February 2020

Abstract
The apple juice sample is extracted with ethyl acetate and the extract is cleaned up by elution from a silica gel column with ethyl acetate-benzene. Patulin is determined by use of a liquid chromatograph, a 25 cm Zorbax-Sil column, and a 254 nm ultraviolet detector. This method has a lower detection limit of 11 μg/L with recoveries of patulin added to apple juice &gt;85%. Gas chromatographic-mass spectrometric analysis of the acetate derivative is used for confirmation. Patulin was detected at levels ranging from 44 to 309 μg/kg in 8 of 13 commercial samples of apple juice.
Gas-Liquid Chromatography of Trichlorfon in Soluble Powder Formulations
Authors: Bowman Phil B , Dame Peter W 
Published: February 2020

Abstract
A procedure is described for the determination of trichlorfon in a soluble powder formulation by gas-liquid chromatography. Silylation prevents on-column degradation of trichlorfon to dichlorvos. The procedure provides quantitative recovery from the formulation as demonstrated by a spiking study. A relative standard deviation of less than 2% was obtained for 6 replicate assays of a single lot of formulation. The mass spectral fragmentations of trichlorfon and trichlorfon-trimethylsilyl ether are described.
Automated System for the Gas-Liquid Chromatographic Determination of Acetaldehyde, Ethyl Acetate, and Fusel Oils in Alcoholic Beverages
Authors: Burgett Charles A 
Published: February 2020

Abstract
An automated gas-liquid chromatographic (GLC) system, including automatic sampling, calculation, and reporting, was applied to the analysis of 7 samples representing 4 types of alcoholic beverages. Using a GLC column packed with glycerol-1,2,6-hexanetriol on Gas-Chrom R and a flame ionization detector, the following compounds were separated and quantitatively measured: acetaldehyde, ethyl acetate, propanol, isobutanol, active amyl alcohol, and isoamyl alcohol. Acetal is resolved from the other compounds.
Collaborative Study of a Potentiometric Titration Method for Determining Sodium Chloride in Foods
Authors: Brammell Wallace S 
Published: February 2020

Abstract
The official final action potentiometric titration method for sodium chloride in canned vegetable products was modified to provide a general quantitative method for foods. The product is dispersed with water and acidified, and soluble chlorides are titrated potentiometrically with silver nitrate. The method is applicable to levels of ≥0.03% sodium chloride. As in all methods involving precipitation of chlorides with silver nitrate, bromide and iodide interfere but not significantly at the levels found in most foods. Interference by protein, amino acids, and phosphate, hydroxyl, carbonate, sulfate, and fluoride ions is prevented by acidifying the sample. In the collaborative study, 10 collaborators successfully analyzed 12 different foods (beef broth, soy sauce, salted whole eggs, margarine, prepared mustard, baby food (carrots), bread, TV dinner, parmesan cheese, canned salmon, ham, and peanut butter), obtaining coefficients of variation ranging from 0.49 to 5.99%, an indication of the precision of the method. Potentiometric titration of chloride in ashed and nonashed samples gave close agreement for sodium chloride content, showing that protein and other organic matter present do not interfere, that ashing is not necessary, and that dispersion or blending with water is adequate for sample preparation. With the proposed method, the sodium chloride content of a food sample can be determined with precision and accuracy in 2—6 min. The method has been adopted as interim official first action.
Thin Layer Chromatographic Identification of Crimidine in Animal Stomach Contents in Experimentally Induced Castrix Poisoning
Authors: Hoskam Elisabeth G , Beek Huug Van 
Published: February 2020

Abstract
Crimidine (2-chloro-4-dimethylamino-6-methylpyrimidine), the active ingredient of the rodenticide Castrix, is extracted from animal stomach or gizzard contents with chloroform in an alkaline medium. The extract is used for thin layer chromatography on a silica gel or polyamid sheet containing a fluorescent indicator; water-30% ammonia (100+2) or water-methanol-30% ammonia (80+20+2) is the mobile solvent. After drying, crimidine appears under ultraviolet light as a dark spot on a fluorescent background. Amounts of 5 μg crimidine are clearly visible; the purple-red dye present in Castrix kernels remains on the baseline.
Zirconium Dioxide, A New Catalyst, in the Kjeldahl Method for Total Nitrogen Determination
Authors: Glowa William 
Published: February 2020

Abstract
The standard Kjeldahl method for the determination of total nitrogen in fertilizers, feeds, foods, and beverages has been modified to eliminate the use of mercuric oxide, which is poisonous to the environment. A new mixed catalyst, consisting of 0.60 g cupric sulfate and 0.20 g zirconium dioxide in combination or 0.70 g zirconium dioxide alone, is recommended to replace the 0.70 g or more of mercuric oxide used in all official macro Kjeldahl methods.
Extraction and Analysis of Aroclor 1254 Components in Blood
Authors: Welborn Michael E , Borchard Ronald E , Hansen Larry G , Metcalf Robert L 
Published: February 2020

Abstract
Extraction, cleanup, and quantitation methods for polychlorinated biphenyls (PCBs) are discussed with reference to the analysis of individual chromatographic peaks as well as total PCBs. Extraction of blood samples with hexane-saturated acetonitrile maintains the integrity of the biologically modified PCB profile and permits accurate description of pharmacokinetic parameters. Individual components are quantitated by measuring peak heights in varying concentrations of Aroclor so that residues can be reported relative to the parent mixture. Absolute quantitation of component peaks can be accomplished by using these relative values and the percentage composition of the Aroclor.
Gas-Liquid Chromatographic Determination of Fenitrothion in Fish, Water, and Sediment
Authors: Grift Norbert , Lockhart W Lyle 
Published: February 2020

Abstract
A procedure is described for the determination of fenitrothion (O,O-dimethyl O-4-nitro-3- methylphenyl thiophosphate) residues in fish tissue, water, and sediment. Fish and sediment samples are extracted with ethyl acetate and cleaned up by partitioning with hexane and passing through Florisil columns. Extracts are analyzed by gas-liquid chromatography, using a flame photometric detector to determine phosphorus and sulfur. Mean recoveries of triplicate analyses of fish muscle samples spiked with 0.1-5.0 μg fenitrothion/g were 94舓110%.
Confirmation of Six Organothiophosphorus Pesticides by Chemical Derivatization at Nanogram Levels
Authors: Singh Joginder , Lapointe Michel R 
Published: February 2020

Abstract
A confirmatory procedure is described in which organothiophosphorus compounds are oxidized by neutralized sodium hypochlorite solution and the oxidation products are subjected to gas-liquid chromatography, using a flame photometric detector. Six pesticides, diazinon, ronnel, malathion, parathion, methyl parathion, and fenitrothion, were studied in 4 different substrates, peaches, blueberries, apples, and lettuce, at fortification levels of 0.25-0.5 ppm. These pesticides can be confirmed when present individually or in combination. Three pesticides, parathion, malathion, and diazinon, were shown to produce the corresponding oxons or oxygen analogs with retention times identical with the corresponding oxon reference standards.
Determination of EPN, Its Oxygen Analog, and p-Nitrophenol in Aqueous Suspensions and Enzymic Digests
Authors: Bhagwat Vasanti M , Ramachandran Bhikshander V 
Published: February 2020

Abstract
O-Ethyl O-p-nitrophenyl phenylphosphonothioate (EPN), its oxygen analog O-ethyl O-p-nitrophenyl phenylphosphonate (EPNO), and p-nitrophenol (PNP) are completely extractable from slightly acidic aqueous suspensions or enzymic digests by a mixture of equal volumes of benzene and isobutanol. In shaking the extract with 0.05N NaOH, PNP is quantitatively partitioned into the aqueous phase and can be determined spectrophotometrically at 410 nm. Aliquots of the solvent phase which now contains EPN and EPNO are evaporated to dryness at 120°C. One portion of the residue is treated with ethanol and alkaline hydroxylamine. The PNP liberated is equivalent to the total EPN -f EPNO. Another portion of the residue is dissolved in cyclohexane and shaken with alkaline hydroxylamine. EPNO, which has a greater reactivity and is more soluble in water, is rapidly decomposed to PNP and can be measured as above. EPN remains unaffected in the cyclohexane phase under these conditions. The value for EPN is calculated either by difference or, when necessary, by evaporating the cyclohexane and decomposing the residue with ethanol and hydroxylamine. The method is sensitive to 0.1 μmole EPN, EPNO, or PNP and can be used in the study of enzyme systems converting EPN and EPNO to PNP or EPN to EPNO. It can also be used in monitoring the preparation of EPNO from EPN by bromine water.
Evaluation of an Automated Dual-Channel Hydroxylamine Assay Procedure for Formulated Penicillin Products. II. Intact Solid Dosage Formulations
Authors: Lane Jonathan R 
Published: February 2020

Abstract
The dual-channel hydroxylamine method of Stevenson, Bechtel, and Coursen for the potency determination of formulated penicillins has been evaluated for use as an official Food and Drug Administration (FDA) alternative assay method for solid dosage formulations. A modified Technicon SOLIDprep Sampler I was used to assay a wide range of penicillin capsules and compressed tablets. In some instances, as many as 10 tablets/sample cup were tested. Results by this method and the official FDA manual method are compared. Some of the problems encountered in the analysis of ampicillin trihydrate capsule formulations and with compressed, film-coated tablets are also described. Based on the performance of the automated system and the data obtained, recommendations have been made to make the dual-channel hydroxylamine procedure an official FDA alternative assay technique for penicillin formulations.
Spectroanalytical Parameters of Fungal Metabolites. IV. Moniliformin
Authors: Lansden J A , Clarkson R J , Neely W C , Cole R J , Kirksey J W 
Published: February 2020

Abstract
The spectral data for a novel fungal metabolite, moniliformin (potassium salt of 1-hydroxycyclobut- 1-ene-3,4-dione), are reported. The corrected ambient temperature fluorescence excitation and emission spectra are given and the quantum efficiency is calculated to be 5.32 × 10舓3. The uncorrected low temperature phosphorescence emission spectrum and lifetime are also reported. Other physical data are given to support spectral evidence that the molecule exists as a dimer in aqueous solutions.
Two-Dimensional Thin Layer Chromatography of Aflatoxins in Figs
Authors: Allen Lewis 
Published: February 2020

Abstract
A method is described for the identification and analysis of aflatoxins in figs. This method is based on 2-dimensional thin layer chromatography, using an antidiagonal spotting technique after sample cleanup in accordance with AOAC official first action Method I for nuts and nut products, 26.015-26.020. Plates were developed in the first direction with toluene-ethyl acetate-90% formic acid (5 + 4 + 1) and in the second direction with acetone-chloroform (1 + 9). Results obtained by this method and those obtained by conventional thin layer methods are comparable. The advantage of the described method, however, is that a fluorescent artifact present in figs no longer interferes in the B2-G1 region.
Stability of Salmonella Biochemical and Serological Characteristics After Long-Term Refrigerated Storage
Authors: Wilson Clyde R , Poelma Paul L , Romero Aida , Andrews Wallace H 
Published: February 2020

Abstract
Viable Salmonella were found in 3 of 4 Salmonella cell suspensions after 6舓8 years of storage in physiological saline at 4°C. Biochemical and serological reactions of the surviving microorganisms remained typical.
Determination of Altosid Insect Growth Regulator in Waters, Soils, Plants, and Animals by Gas-Liquid Chromatography
Authors: Miller Wayne W , Wilkins James S , Dunham Loren L 
Published: February 2020

Abstract
Residues of isopropyl (2E,4E)-ll-methoxy-3, 7,1 l-trimethyl-2,4-dodecadienoate (Altosid®) insect growth regulator are determined in waters, soils, plants, milk, eggs, fish, shellfish, poultry and cattle tissues, blood, urine, and feces. Acetonitrile is the primary extraction solvent for all samples. Residues are extracted by high-speed blending followed by vacuum filtration. Fatty extracts are subjected to cold-temperature precipitation and filtration. Samples are cleaned up by petroleum ether partitioning and Florisil and neutral alumina chromatography. The concentrated eluants are analyzed by gas-liquid chromatography (GLC) on columns of differing polarity, using hydrogen flame ionization detectors. The identity of suspected residues is confirmed by additional GLC and by mass fragmentography. The lower limits of detection were: water samples, 0.0004–0.001 ppm; soils, blood, and urine, 0.001 ppm; forage grasses, forage legumes, and rice foliage, 0.005 ppm; and milk, eggs, fish, shellfish, poultry and cattle tissues, and feces, 0.010 ppm.
Modification of the Official Fluorometric Method for Selenium in Plants
Authors: Olson Oscar E , Palmer Ivan S , Cary Earle E 
Published: February 2020

Abstract
The official first action AOAC fluorometric method for selenium in plants, 3.074–3.078, has been modified to simplify the method and to make it more accurate. The digestion time has been increased from 15 to 30 min past the appearance of perchloric acid fumes to better assure complete oxidation of all forms of selenium to selenite. Preparation of the 2,3-diaminonaphthalene solution, the reagent used for fluorometric analysis, has been changed so that the reagent is stable for several weeks; in the previous writeup, this solution had to be prepared daily. Special equipment (micro-Kjeldahl flasks with ground glass joints) has been eliminated and cyclohexane has been substituted for decahydronaphthalene. The modified method is convenient and applicable to a wide range of materials; it yields results comparable to those from the official method.
Comparison of Virus Recovery Techniques for Assessing the Virucidal Activity of Disinfectant Spray Products
Authors: Chen John H S 
Published: February 2020

Abstract
A comparison was made of virus recovery from inoculated glass surfaces by 3 different viral recovery techniques used in spray test methods. On a total of 7, 5, and 5 observations, for the cover glass crushing, cotton swab rubbing, and microscopic slide shaking techniques, respectively, the log reduction of the median tissue culture infective dose (log TCID50/ml) averaged 1.48, 2.57, and 2.22, the mean percentage recovery was 77.98, 61.55, and 66.94%, and the coefficient of variation was 4.37, 10.01, and 7.42%. The cover glass technique was found to be the least variable and the most effective and precise of the 3 methods.
Gravimetric Determination of Carbon Dioxide in Wines
Authors: Castillo Graham A 
Published: February 2020

Abstract
A gravimetric determination of CO2 in wines was both accurate and relatively fast when compared with the titrimetric method. When 21 samples of lightly carbonated wine were analyzed by both methods the average results agreed within 0.2 mg (range of agreement from 0.1 to 5.0 mg CO2/100 ml wine). In the gravimetric procedure, the CO2 contained in the wines is converted into the carbonate by adding 50% NaOH to the previously chilled sample. An aliquot is introduced into a closed vacuum system. The CO2 is evolved by adding HCl and shaking and warming the reaction flask. The generated gases are pulled through the system by a vacuum pump. Along the path, the gases are dried and purified, and finally the CO2 is absorbed by Indicarb reagent between layers of anhydrous magnesium perchlorate. The absorption bulb is weighed before and after absorption of CO2.
Collaborative Study of Microchemical Sulfur Determination, Using Oxygen Flask Combustion: THQ Indicator
Authors: Scroggins Laverne H 
Published: February 2020

Abstract
A collaborative study was conducted on microchemical sulfur determination by oxygen flask combustion. Seven collaborators performed duplicate determinations on 5 samples: sulf anilamide, benzylisothiourea hydrochloride, cystine, potassium sulfate, and a mixture of potassium sulfate and phosphate. Following oxygen flask combustion, the resultant gases were absorbed in a solution containing 0.1/V NaOH and 30% H2O2. The acidified sample was shaken 30 min and evaporated to dryness on the steam bath; the sulfate was titrated with standard barium chloride solution. The indicator used in this study was tetrahydroxyquinone. Its reliability has been previously proved and adopted by AOAC for use with the Carius-type combustion. Evaluation of the statistical data and overall consideration indicate satisfactory results for all types of compounds studied, with the exception of phosphorus-contaminated samples. Both systematic and random errors for the pure compounds were low. The method has been adopted as official first action.
Formation of Aflatoxin Derivatives on Thin Layer Chromatographic Plates
Authors: Przybylski W 
Published: February 2020

Abstract
Rapid confirmation of the presence of aflatoxing B1 and G1 in foods is provided by reaction with trifluoroacetic acid at the origin of a thin layer chromatographic plate. The procedure has been used successfully with various nuts, grains, coffee and cocoa beans, and other foods.
Determination of Fat in Body Tissues and in Food Mixtures
Authors: Conway Emily S , Adams Mildred 
Published: February 2020

Abstract
The official final action acid hydrolysis method, 14.019, for the determination of fat in foods was successfully applied, with slight modifications, to the analysis of homogenates of food, feces, and animal tissues as well as dry samples of mixed foods. In samples containing sucrose or fructose, it was necessary to carry out a fermentation procedure before acid hydrolysis to avoid problems encountered when these sugars were present.
Carbaryl Insecticide: Extraction from Dust and Powder Formulations
Authors: Mcdermott William H 
Published: February 2020

Abstract
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, 6.206–6.208. A repeatability extraction study has been made, using a different extraction technique with both chloroform and 10% methanol in chloroform. The results indicate that the new extraction technique and the mixed solvent are suitable for all solid carbaryl formulations. It is recommended that a collaborative study be conducted on the new solvent system and extraction technique.
The Purity of Sulfanilic Acid
Authors: Marmion Daniel M 
Published: February 2020

Abstract
Thirteen samples of sulfanilic acid from various sources were evaluated for purity, using a variety of instrumental and chemical methods. The properties considered include strength, moisture, insoluble materials, iron, sodium, aniline sulfate, orthanilic acid, nictanilic acid, aniline- 2,4-disulfonic acid, and absorptivity. In general, the samples were found to be organically pure and reasonably consistent in quality.
Collaborative Study of a Semiautomated Method for the Analysis of Acenocoumarol, Phenprocoumon, and Potassium Warfarin Tablets
Authors: Kolinski Richard E 
Published: February 2020

Abstract
This collaborative study was undertaken to determine if the anticoagulants acenocoumarol, phenprocoumon, and potassium warfarin could be analyzed by the automated analysis system described in the collaborative study for the analysis of sodium warfarin and dicumarol. Collaborators were supplied with a composited tablet sample of each anticoagulant. Results agreed well with the National Formulary methods for phenprocoumon and potassium warfarin, and an unpublished method for acenocoumarol. For acenocoumarol, coefficients of variation on individual sets of data ranged from 0.30 to 1.94% For phenprocoumon, coefficients of variation ranged from 0.52 to 1.20%. For potassium warfarin, coefficients of variation ranged from 0.54 to 1.79%. The results of this study show that acenocoumarol, phenprocoumon, and potassium warfarin can be analyzed by the official AOAC method for the analysis of sodium warfarin and dicumarol tablets.
Determination of Potassium Guaiacolsulf onate by Ion-Pairing Partition Chromatography
Authors: Doyle Thomas D , Proctor Joseph B 
Published: February 2020

Abstract
Potassium guaiacolsulfonate, a highly polar, acidic substance, is readily eluted by chloroform from a pH 4.5 Celite column in the form of its ion-pair with trihexylamine, thereby effecting facile separation from other pharmaceuticals. The sulfonic acid is then back-extracted into aqueous alkali and determined spectrophotometrically. Assay of standard solutions by this procedure averaged 100.44±0.81%. The method was applied successfully to 4 commercial cough preparations containing a variety of other drugs.
Gas Chromatographic Resolution of Organochlorine Insecticides on OV-l/OV-17, OV-210/OV-17, and OV-225/OV-17 Mixed Phase Systems
Authors: Suzuki Manabu , Yamato Yasuhiro , Watanabe Tadao 
Published: February 2020

Abstract
The resolution of organochlorine insecticides and their related compounds on OV-l/OV-17, OV-210/OV-17, and OV-225/OV-17 mixed phase column systems was investigated. Four BHC isomers and p,p'-DDT, its isomer, and their metabolites (except p,p'-DDE and o,p'-DDE) were resolved on the OV-210/OV-17 system. Heptachlor and heptachlor epoxide were separated on 5% OV-1/2% OV-17 or 5% OV-225/2% OV-17. Resolution of aldrin, dieldrin, and endrin was obtained on 5% OV-210/2% OV-17. p,p'-DDE and o,p'-DDE could not be separated by any of the systems studied.