bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improved Enrichment for Recovery of Shigella sonnei from Foods
Authors: Mehlman Ira J , Romero Aida , Wentz Barry A 
Published: February 2020

Abstract
Shigella species were recovered from foods by the procedure described in the Bacteriological Analytical Manual, 5th Ed. The method is effective if Shigella species are present at about 106 cells/g. A 25 g food portion was incubated in Gram-negative (GN) and selenite cystine broths for 16 h at 35°C and streaked onto MacConkey, Levine's eosin methylene blue, desoxycholate citrate, and xylose lysine desoxycholate agars. 5. sonnei cells were recovered quantitatively at 44.5°C, and along with other Shigella species, were grown with Escherichia coli in a tryptone broth under anaerobic conditions. Shigella species were also grown in a mixed microflora from foods. 5. sonnei cells were inoculated into an enrichment broth containing 20 g tryptone, 2 g K2HPO4, 2 g KH2PO4, 1 g glucose, 5 g NaCl, 1.5 mL Tween 80, and 0.5 mg novobiocin/L (pH 7.0) and incubated for 20 h at 44°C. Enrichments were streaked onto MacConkey agar and the plates were incubated 20 h at 35°C. Suspect Shigella colonies were screened in glucose, tryptone, and lysine broths and in triple sugar iron and motility agars. The sensitivity varied from 0.3 to 1000 bacteria/g. The method has been examined with artificially inoculated lettuce, celery, brussels sprouts, mushrooms, and hamburger. It is also applicable to S. flexneri if incubation is conducted at 42°C.
Proton Magnetic Resonance Spectroscopic Assay of Propoxur
Authors: Lesser Joseph H , Kreps Saul I , Friedman Ella 
Published: February 2020

Abstract
A procedure is described for the assay of propoxur (o-isopropoxyphenyl N-methylcarbamate) by nuclear magnetic resonance (NMR) spectroscopy. Methanol was used as internal standard and chloroform as solvent. Known standard and technical materials were analyzed and results of NMR and liquid chromatographic methods were compared. The NMR method is straightforward, with a precision of ± 1.6% (95% confidence limits) for 2 sample weighings.
Gas Chromatographic Determination of Alachlor in Formulations: Collaborative Study
Authors: Tomkins David F 
Published: February 2020

Abstract
An isothermal gas chromatographic method for measuring alachlor in formulations was tested by 26 collaborators. The samples were prepared in acetone and determined with a gas chromatographic column of 10% SP 2250 on 100-120 mesh Supelcoport and with di-n-pentyl phthalate as internal standard. Collaborators made single determinations on each of 2 similar materials (matched pairs) on 2 days for 3 pairs of samples. The study generated 44 matched pairs which were used in Youden's matched-pair calculations. The coefficients of variation (CV,) for liquid formulations were 1.23% and 0.94%, while the CV, for the granular formulation was 1.60 %. The method was simple to use and did not reveal any interferences in the samples tested. The method has been adopted official first action.
Gas Chromatographic Method for Determination of Fenitrothion in Technical and in Emulsifiable Concentrate and Water-Dispersible Powder Formulations: Collaborative Study
Authors: Mount Dwight L , Miles James W 
Published: February 2020

Abstract
A variety of column packings and internal standards were evaluated to determine the most satisfactory system to use in a gas chromatograhpic (GC) method for analysis of fenitrothion, technical and formulations. Fenitrothion and the most closely related isomer, 00- dimethyl 0-(4-methyl-3-nitrophenyl) phosphorothioate, were resolved on columns packed with OV-210 and with polyphenyl ether, 6-ring (PPE-6R). A method based on the separation of fenitrothion on a PPE- 6R column with fluoranthene as internal standard was selected for use in a limited collaborative trial and later for use in a full-scale collaborative trial with 21 collaborators participating. Each collaborator was furnished matched pairs of samples of technical fenitrothion, emulsifiable concentrate, and water-dispersible powder. The coefficients of variation (CV) for the paired samples were 1.02,1.11, and 1.01, respectively, for technical fenitrothion, emulsifiable concentrates, and waterdispersible powders. Data are also presented for an alternative method in which compounds are separated on an OV-210 column with dibutyl sebacate as the internal standard. The method has been adopted official first action.
Gas Chromatographic Determination of Chlordimeform in Pesticide Formulations: Collaborative Study
Authors: Gale Thomas G , Hofberg Arthur H 
Published: February 2020

Abstract
Agaschromatographic (GC) procedure for the determination of chlordimeform in emulsiflable concentrate formulations containing about 46% active ingredient was collaboratively studied using the matched pair scheme. Chlordimeform was extracted from the formulation with methylene chloride containing diethyl terephthalate as the internal standard, chromatographed on CBWX-20M, and detected by flame ionization. Determinations on the 4 samples by 20 government, university, and industrial collaborators using peak area measurements showed within-laboratory repeatability of better than 1%. Reproducibility was 1.2% for the formulation. The method has been adopted official first action.
Capillary Gas Chromatographic Determination Of Cypermethrin In Formulations:
Collaborative Study
Authors: Bland Peter D 
Published: February 2020

Abstract
A method is described for the determination of cypermethrin, 3-(2,2- dichloroethenyl)-2,2-dimethyl-cyclopropanecarboxylate cyano-(3- phenoxyphenyl)methyl ester, in technical and formulated material by capillary gas chromatography (CGC). Samples of technical or formulated material are dissolved in CH2Cl2 containing dicyclohexyl phthalate as internal standard. The solution is injected into a gas chromatograph fitted with a flame ionization detector and capillary column of 25 m x 0.32 mm fused silica with a thick film OV-1 phase at 240°C. Injection is made into a heated injection port fitted with an antidiscrimination device in a split mode. Peak areas obtained at retention times of the internal standard and active ingredient are measured with an integrator. The quantity of cypermethrin is determined by comparing the internal standard and active ingredient peak areas with those obtained from a calibration solution containing known amounts of internal standard and pure active ingredient. Five samples were chosen for collaborative study: technical cypermethrin, 70% liquid concentrate, 3 lb/US gal. emulsifiable, 3 ib/US gal. oil concentrate, and 40% wettable powder. Twelve collaborators carried out replicate determinations on each sample on separate days. Coefficients of variation between laboratories (CVX) were 2.13 for the technical, 2.94 for the emulsifiable concentrate, 3.51 for the liquid concentrate, 2.66 for the wettable powder, and 2.29 for the oil concentrate. The method was adopted official first action.
Liquid Chromatographic Monitoring of the Depletion of Carbadox and Its Metabolite Desoxycarbadox in Swine Tissues
Authors: Macintosh Agnes I , Lauriault Ginette , Neville George A 
Published: February 2020

Abstract
A liquid chromatographic method was used to monitor a depletion study of carbadox (and its most important metabolite, desoxycarbadox) in young pigs fed carbadox-treated rations for 1 week. Carbadox was found in blood (20 ppb), blood serum (26 ppb), and muscle tissue 24 h after withdrawal from treated ration; residues were reduced to a trace (&lt; 2 ppb) in 48 h, and eliminated by 72 h. Desoxycarbadox, although not detected in blood, was found in muscle (17 ppb) 24 h after withdrawal; it was reduced to 9 ppb at 48 h and to a trace by 72 h. Although no carbadox was detected in liver 24 h after withdrawal, appreciable desoxycarbadox (125 ppb) was found in liver 24 h after withdrawal; it was reduced to 17 ppb at 48 h and to a trace by 72 h. Whereas only a trace of carbadox was found in kidney 24 h after withdrawal, 186 ppb desoxycarbadox was found in kidney at 24 h, 34 ppb at 48 h, and a trace at 72 h. No metabolite of carbadox other than desoxycarbadox was found in extracts of swine tissues during this medicated feed trial, and no metabolite was found in blood extracts by using the established 'methodology. The effect of tissue storage (aging) at - 20°C on levels of the drug and its metabolite was a modest alteration of residue levels. The inadvertent use of feed adulterated with furazolidone and initially medicated with chlortetracycline, sulfamethazine, and penicillin G, did not affect the uptake of carbadox in this depletion study or interfere ) with the analytical methodology.
Determination of Internal Insect Infestation of Oats: Collaborative Study
Authors: Trauba Richard L 
Published: February 2020

Abstract
An improved method has been developed for determining internal insect infestation of oat kennels. The method involves alcohol defatting and acid hydrolysis of the cracked oats, wet sieving to remove the acid, transfer to a 2 L Wildman trap flask, deaeration by boiling, and treatment with Tween 80-Na.tEDTA. Insects are extracted with light mineral oil. Reports from 6 collaborators showed that recoveries averaged 88.98% for adult insect heads and 97.22% for larvae. The method has been adopted official first action.
Organochlorine Pesticides and Polychlorinated Biphenyls in Sediment and Fish from Wetlands in the North Central United States
Authors: Martin Dan B , Hartman William A 
Published: February 2020

Abstract
Sediment samples collected in 1980-1982 from riverine and pothole wetlands at 17 locations in the north central United States were analyzed for organochlorine pesticides, certain of their metabolites, and polychlorinated biphenyls (PCBs). Concentrations were above minimum detection levels (5 ng/g of organochlorines and 20 ng/g of PCBs) in less than 4% of the samples taken. Fish samples taken at 9 of these 17 locations, and analyzed for the same compounds, showed a higher frequency of detectable contaminants. The most common compound found in fish was DDE, which was found in 51% of the samples at levels up to 512 ng/g. a-BHC was present at concentrations of 5 to 27 ng/g in 36% of the fish samples, and DDD was found at levels of 5 to 60 ng/g in 14%. Four other compounds, DDT, dieldrin, PCB, and Ira/ts-nonachlor, were detected in fish at relatively low concentrations in less than 10% of the samples. This survey, thus, indicated little contamination by organochlorine pesticides or PCBs in the wetland habitats of this region.
Capillary Gas Chromatographic Determination of Prometryn and Its Degradation Products in Parsley
Authors: Bardalaye Promode C , Wheeler Willis B 
Published: February 2020

Abstract
Residue analysis of the herbicide prometryn (2,4-bis(isopropylamino)- 6-methylthio-l,3,5-triazine) is widely known, but an analytical method for determining its metabolities or degradation products in addition to the parent chemical has not yet been reported in the literature. The procedure reported here is for the extraction and determination of prometryn and 2 metabolites, 2-amino-4-isopropylamino-6-methylthio- l,3,5-triazine and 2,4-diamino-6-methylthio-l,3,5-triazine, in parsley. Crops were extracted with 2-propanol followed by concentration of the extract and partitioning with a minimum amount of hexane in the presence of a large excess of water to remove most of the green pigment. The aqueous phase was divided into 2 equal halves: (A) Onehalf portion was partitioned with dichloromethane in the presence of saturated sodium chloride solution, the dichloromethane phase was separated, and the aqueous phase was discarded. The organic solvent was evaporated, and the contents were reconstituted in petroleum ether before prometryn analysis. (B) The other half was made slightly alkaline with ammonium hydroxide solution and was partitioned with ethyl acetate in the presence of saturated sodium chloride solution. The ethyl acetate phase was concentrated, centrifuged to remove any turbidity, and analyzed for the 2 metabolities above. Fused silica capillary gas chromatography (GC) with nitrogen-phosphorus (N-P) detection was used for quantitation. The limit of detection was 0.05 mg/kg for all the compounds examined. Recoveries from fortified parsley samples ranged from 59 to 73% at fortification levels of 0.05 to 1.0 mg/kg.
Liquid Chromatographic Assay of Tetracyclines in Tissues of Food-Producing Animals
Authors: Ashworth Raymond B 
Published: February 2020

Abstract
A survey of the literature is presented on liquid chromatographic (LC) determination of tetracyclines in plasma, urine, and tissues of foodproducing animals. Food Safety and Inspection Service (FSIS) research on tetracyclines during 1973-1984 is discussed, including the thin layer chromatographic qualitative identification method for tissues. Research on development of LC column packings for trace level chromatography of tetracyclines and anhydrotetracyclines is also discussed. Data are shown for recovery, ruggedness testing, and analyst qualification studies on the tentative version of the LC method
Enzymatic-Ultraviolet Determination of Glucose and Fructose in Wine: Collaborative Study
Authors: Henniger Guenther , Mascaro Leonard 
Published: February 2020

Abstract
This collaborative study on the determination of glucose and fructose in wine was performed by 18 laboratories on 4 matched pairs of commercial wine. The method uses the enzymes hexokinase, glucose-6- phosphate dehydrogenase, and phosphoglucose isomerase and the coenzyme nicotinamide-adenine dinucleotide phosphate. Both glucose and fructose can be determined in the same sample without separation. The method is simple but care is necessary to ensure precise transfer of small volumes. Repeatability and reproducibility standard deviations for glucose ranged from 2.6 to 14.6 mg/L and 4.7 to 16.5 mg/L, respectively. Repeatability and reproducibility values for fructose ranged from 2.4 to 16.1 mg/L and 6.0 to 21.3 mg/L, respectively. The method has been adopted official first action
Enzymatic-Ultraviolet Determination of L-Citric Acid in Wine: Collaborative Study
Authors: Henniger Guenther , Mascaro Leonard 
Published: February 2020

Abstract
A collaborative study was carried out on an enzymatic method for the determination of L-citric acid in wine, using the enzymes citrate lyase, malate dehydrogenase, and lactate dehydrogenase and the coenzyme nicotinamide-adenine dinucleotide phosphate. The study was performed by 18 laboratories using 4 blind duplicates of commercial wine. The method is simple and shows good precision. Coefficients of variation (CV) for reproducibility ranged from 1.8 to 3.4%; CVs for repeatability ranged from 0.76 to 2.62%. Analysts are cautioned to check the linear absorbance response of their spectophotometers when performing this assay and also to take care in pipetting the relatively small volumes used in this procedure. The method has been adopted official first action
Ion-Pair Column Chromatographic Determination of Trimethobenzamide Hydrochloride in
Capsule and Injection Dosage Forms: Collaborative Study
Authors: Naviasky Helen 
Published: February 2020

Abstract
An ion-pair column chromatographic method was developed for the determination of trimethobenzamide hydrochloride in capsules and injection dosage forms. Detection is by UV spectrophotometry at 261 nm. Recoveries by the Associate Referee ranged from 98.3 to 101.0% for the drug substance. Results by 5 collaborators for capsules averaged 99.1% of labeled or theoretical with coefficients of variation (CVs) of 1.81% (reproducibility) and 1.17% (repeatability); results for injec- , tions averaged 100.4% of labeled or theoretical with CVs of 1.91% (reproducibility) and 0.69% (repeatability). The method has been adopted official first action
Sample Preparation for Chromatography of Amino Acids: Acid Hydrolysis of
Proteins
Authors: Gehrke Charles W , Wall Larry L , Absheer Joseph S , Kaiser Floyd E , Zumwalt Robert W 
Published: February 2020

Abstract
A number of variations were evaluated in the techniques and procedures of the classical 6N hydrochloric acid, 110°C, 24 h hydrolysis of protein. Variations included the use of glass tubes with Teflon-lined screw caps as the hydrolysis vessel, high-temperature short-time hydrolysis, performic acid oxidation of cystine and methionine, multiple hydrolysis times at 145°C, and interlaboratory preparation of hydrolysates. A diverse sample set used in the study included a range of protein-containing matrices, and automated ionexchange chromatography was used for the amino acid analysis. Results show that for hydrolysis in glass tubes with Teflon-lined screw caps at 110°C for 24 h, recoveries of amino acids were in good agreement with recoveries by classical hydrolysis in sealed glass ampoules at reduced pressure. Recoveries from a higher temperature hydrolysis, i.e., 145°C for 4 h and using sealed ampoules, were also in agreement with 110°C, 24 h, sealed ampoule results; the former procedure yielded increased isoleucine and valine and decreased serine and threonine values. Glass tubes with Teflon-lined screw caps for hydrolysis were found to be a practical and convenient alternative to sealed glass ampoules; the improved precision with the former was probably due to the simplicity of the method.
The average recovery of cystine from a wide range of matrices without the use of performic acid was 55.5% compared with results obtained with performic acid oxidation. Similarly, methionine is preferably analyzed as methionine sulfone.
Interlaboratory evaluation of 145°C, 4 h hydrolysis, in which one laboratory used sealed ampoules and the other laboratory used Teflon-lined screw-cap tubes, demonstrated excellent agreement of amino acid values.
Analysis of Fat-Soluble Vitamins. XXIX. Liquid Chromatographic Determination of Vitamin D in AD Concentrates: Collaborative Study
Authors: De Vries Ellen J , Borsje Ben 
Published: February 2020

Abstract
A simplified liquid chromatographic (LC) method for determining vitamin D in vitamin AD concentrates (&gt; 5000 IU vitamin D/g) was collaboratively studied. In the simplified method, the 2 columns specified in AOAC LC method 43.101-43.109 are replaced by a single column, which separates the vitamin D isomers and the vitamin A esters. The procedure for oils includes dissolution and quantitation by normal phase LC. Dry multivitamin concentrates and aqueous dispersions are treated with an enzyme system and the vitamins are extracted with n-pentane. Six coded samples were distributed to 16 laboratories; 15 collaborators returned their results. Estimates of repeatability and reproducibility for the oil samples were 1.1 and 3.1%, respectively; for the high-level concentrated dry preparation 1.4 and 3.9% and for the low-level concentrated dry preparation 1.3 and 11.4%, respectively. These values are a considerable improvement over the results obtained in the 1979 multivitamin collaborative study. The method has been adopted official first action for determination of vitamin D in vitamin AD concentrates containing s 5000 IU vitamin D/g.
Ruggedness Testing of the Official Method for Rot Fragments in Comminuted Tomato Products
Authors: Russell Gerald E 
Published: February 2020

Abstract
The official AOAC method for rot fragments in comminuted tomato products (44.224) has been revised on the basis of Youden's ruggedness testing procedures to provide better control over the sources of variability. Two sets of ruggedness tests were carried out to evaluate the type of balance used to weigh the sample, amount of stain, staining time, sieve design, technique used to transfer stained material from beaker to sieve, washing technique used to accumulate stained material at edge of sieve, diameter of eye dropper used to transfer sample from sieve to graduated tube, number of 0.5 mL portions examined, and magnification used to examine prepared slides. A 3-way analysis of variance conducted on amount of stain, transfer technique, and washing technique showed that the transfer and washing techniques were significant areas of variability.
Simultaneous Gas Chromatographic Determination of Carboxylic Acids in Soft Drinks and Jams
Authors: Tsuda Taizo , Nakanishi Hiroshi , Morita Takashi , Takebayashi Junko 
Published: February 2020

Abstract
A method was developed for simultaneous gas chromatographic determination of sorbic acid, dehydroacetic acid, and benzoic acid used as preservatives, and succinic acid, fumaric acid, malic acid, and tartaric acid used as acidulants in soft drinks and jams. A sample was dissolved in NH4OH-NH4CI pH 9 buffer solution, and an aliquot of the solution was passed through a QAE-Sephadex A 25 column. The column was washed with water, and the carboxylic acids were eluted with 0.1N HC1. Sorbic acid, dehydroacetic acid, and benzoic acid were extracted with ethyl ether-petroleum ether (1 + 1), and determined on a 5% DEGS + 1% H3PO4 column. Succinic acid, fumaric acid, malic acid, and tartaric acid in the lower layer were derivatized with N,0- bis(trimethylsilyl)acetamide and trimethylchlorosilane, and determined on a 3% SE-30 column. Recoveries from soft drink and jam samples fortified with 0.1% each of 7 carboxylic acids ranged from 92.4 to 102.6% for preservatives, and from 88.1 to 103.2% for acidulants.
Analysis of d-Phenothrin and Its Optical Isomers in Technical Preparations and Formulations
Authors: Doi Tadashi , Sakaue Shigeyuki , Horiba Masao 
Published: February 2020

Abstract
The content of d-phenothrin in technical preparations was determined by gas chromatography (GC) on a column of 2% PEG-20M or 2% DEGS, using suitable internal standards. The cis- and trans-isomers were separated from each other and determined on a 2% QF-1 column. The 4 optical isomers of rf-phenothrin were hydrolyzed in alkaline conditions to liberate chrysanthemic acid, which was derivatized to diastereoisomeric &lt;/-2-octyl esters, and the isomer ratio was determined by GC. The 4 optical isomers were also separated from one another directly on a chiral Sumipax OA-2000 column by liquid chromatography (LC). Also, after the propellant gas in an aerosol formulation was released, and the remaining liquid was analyzed using the same GC conditions as those used for technical preparations
Impurity Problems in Chromatographic Method Studies for Fenthion Formulations
Authors: Boyd Willard G 
Published: February 2020

Abstract
Several gas chromatographic (GC) methods for analyzing fenthion were studied, and flame ionization detection, a glass column packed with SE-52 on Chromosorb GHP, and on-column injection were selected as parameters. No suitable internal standard was found because of coeluting, bias-producing impurities in fenthion. Several liquid chromatographic (LC) methods were also studied, and UV detection, a Zorbax ODS column, and a methanol-water-H3P04 mobile phase were finally selected as parameters. Dipentyl phthalate was selected as internal standard. After testing, this LC method was submitted for collaborative study. During the collaborative study, the manufacturer found an impurity, 3-methyl-4-(methylthio)anisole, co-eluting with fenthion in the collaborative method. The manufacturer's method was then evaluated as an alternative for collaborative study, but a significant unidentified impurity from the formulation blank, used for formulating emulsifiable concentrates, was also found co-eluting with fenthion. The anisole impurity was verified by LC, and the presence of the S-isomer and bis-methylthio-fenthion impurities was found by gas chromatographic- mass spectrometric (GC-MS) analyses. An anisole material obtained from Mobay was also verified by GC-MS analysis. Several other impurities were identified from literature references and from private communication with the manufacturer.
Rapid Liquid Chromatographic Determination of Patulin in Apple Juice
Authors: Forbito Pedro Rafael , Babsky Norma Elena 
Published: February 2020

Abstract
A rapid method is described for the quantitative determination of patulin in apple juice. The mycotoxin is extracted from the sample with ethyl acetate and the extract is cleaned up by extraction with a sodium carbonate solution. Patulin is determined by reverse phase liquid chromatography using a μ.Bondapak C18covery is &gt;75%.