bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rapid Determination of Fumigant and Industrial Chemical Residues in Food
Authors: Daft James L 
Published: February 2020

Abstract
A gas chromatographic (GC) method is described for the determination of 22 fumigant and industrial chemical residues in a variety of foods. The fumigants and industrial chemicals determined are methyl bromide, methylene chloride, carbon disulfide, chloroform, 1,1-dichloroethane, ethylene dichloride, methyl chloroform, carbon tetrachloride, methylene bromide, propylene dichloride, 2,3-dichloropropene, trichloroethylene, 1,3-dichloropropylene, 1,1,2-trichloroethane, chloropicrin, ethylene dibromide, tetrachloroethylene, propylene dibromide, l,l,2,2-tetrachloroethane,j»-dichlorobenzene, o-dichlorobenzene, and l,2-dibromo-3-chloropropane. Except for the latter three, the fumigants are determined at 90°C on 3.6 m 20% loaded OV-101 columns with electron-capture and Hall-electroconductivity detectors. The other 3 compounds (o-dichlorobenzene, p-dichlorobenzene, and l,2-dibromo-3-chloropropane), which elute beyond 30 min on the above columns, are determined at 90°C on 1.8 m 5% loaded OV-101 columns with the same detectors. The ng/g-level fortifications have an overall mean analyte recovery of 70% and a coefficient of variation of 40%. The variety of foods examined includes both fatty and nonfatty food types (e.g., off-the-shelf cooked and uncooked grain-based items, dairy products, fresh and canned fruits and vegetables, and meats). Samples are extracted and cleaned up according to fat content and food type. Samples containing less than 71% fat are extracted by using an aqueous: nonaqueous shakeout (20% acetone solution under isooctane). Most extracts (isooctanes) are analyzed directly. Extracts from samples containing from 21 to 70% fat (e.g., ground beef, pecans, and corn chips) are cleaned up further on micro-Florisil columns to remove excess fat. A few other samples containing more than 71% fat or oil (e.g., butter, salad dressing, and vegetable oil) are diluted directly in isooctane and, depending on the degree of dilution, can be cleaned up further on micro-Florisil columns. Also, clear beverages (e.g., soda and tea) are extracted directly with isooctane. These extraction and cleanup techniques were tested on 231 different table-ready foods. Three-hundred incurred residues of 10 different fumigants were found in 138 items examined; 93 items had no detectable residues. The main advantage of the method is rapid semiquantitative determination of multiple fumigants from all food types.
Liquid Chromatographic Determination of Propranolol Hydrochloride in Various Dosage Forms
Authors: Olsen Carolyn S , Scroggins Henry S 
Published: February 2020

Abstract
A simple and rapid liquid chromatographic method is described for the determination of propranolol hydrochloride in pharmaceutical preparations. The separation was achieved on a reverse-phase octylsilane (C8) column by using a mobile phase composed of a mixture of 0.5 g dodecyl sodium sulfate in 18 mL (0.15 M) H3P04 plus 90 mL methanol, 90 mL acetonitrile, and 52 mL water. Detector response was linear for 0.03-3.1 mg/mL of propranolol. Recoveries from synthetic mixtures ranged from 99.6 to 101.7%. The results obtained by the proposed method were similar to those obtained by the USP XXI method.
Determination of Novobiocin Residues in Milk, Blood, and Tissues by Liquid Chromatography
Authors: Moats William A , Leskinen Laura 
Published: February 2020

Abstract
Residues of novobiocin in milk, blood, and tissues can be detected by microbiological tests but cannot be distinguished from other antibiotics. A simple liquid chromatographic (LC) method was developed for identification of residues. Tissues were blended and milk and blood serum were mixed with 0.2M NH4H2P04. The mixture was deproteinized by adding aqueous methanol and filtering. The LC apparatus consisted of a variable wavelength detector, set at 340 nm, an automatic loop injector, and a C,8 column with guard cartridge. The flow rate was 1 mL/min and the solvent mixture of 0.01M H3P04-acetonitrile-methanol was programmed from 50 + 0 + 50 (0-1 min) to 20 + 80 + 0 (20 min). Novobiocin was concentrated directly by solid-phase extraction on the analytical column. Five or more 200 11L aliquots of the filtrate in water-methanol (1 + 1) (adjusted if necessary) were injected with the column solvent at 50 + 0 + 50. After the final injection, the program was run to completion. Recoveries were 90-100% with sensitivities of 0.05 ppm or less. The procedure should be adaptable for use with formulations and feeds
Determination of Ethyl Carbamate in Distilled Alcoholic Beverages by Gas Chromatography with Flame Ionization or Mass Spectrometric Detection
Authors: Pierce William M , Clark Adora O , Hurst Harrell E 
Published: February 2020

Abstract
Quantitative methods are detailed for determination of ethyl carbamate in distilled alcoholic beverages by capillary gas chromatography with flame ionization detection (GC/FID) and by packedcolumn gas chromatography/mass spectrometry (GC/MS) using selected ion monitoring. Five g samples of distillate of known ethanol concentration are diluted with water to 25% ethanol (v/v), washed with petroleum ether, and extracted with dichloromethane prior to GC/FID or GC/MS analysis. As necessary, sample extracts that exhibit GC/FID interference are passed through alumina for additional cleanup. When internal standards (ferf-butyl carbamate and n-butyl carbamate for GC/FID, or ethyl ,3C-,sN-carbamate for GC/ MS) were used for quantitation, the limit of detection for ethyl carbamate was in the range of 5-25 ppb. Coefficients of variation ranged from 3.5 to 6.0% for GC/FID determinations, and from 1.4 to 3.2% for GC/MS. Correlation between methods for 22 random distillate samples ranging in concentration from approximately 40 to 800 ppb gave a correlation coefficient (r) of 0.996.
Simple Method for Derivatization of Monoglycerides and Diglycerides
Authors: Lee Theresa , Hastilow Christine , Smith Katrina 
Published: February 2020

Abstract
A method has been developed for derivatization of monoglycerides and diglycerides to their propyl esters by using propionic anhydride in the presence of pyridine. The derivatives are volatile and thus can be separated and identified by gas chromatography (GC). Completion of the reaction is monitored by thin-layer chromatography. Monoglyceride propyl esters were positively identified by gas chromatography and by gas chromatography/mass spectrometry. No side products were observed in the derivatization reaction which requires 35 min at 75°C. GC analysis of the mono- and diglyceride propyl esters can be completed in approximately 30 min.
Laboratory Procedures for Detoxification of Equipment and Waste Contaminated with
Brevetoxins PbTx-2 and PbTx-3
Authors: Poli Mark A 
Published: February 2020

Abstract
Procedures are presented for the detoxification of laboratory equipment contaminated with brevetoxins PbTx-2 and PbTx-3. An in vivo bioassay using the Japanese madaka Oryzias latipes monitored toxin activity. Incubation for 10 min with 0.1N NaOH detoxified a lethal dose of either PbTx-2 or PbTx-3 to levels below the detection limit of the assay (&lt;10 ng/mL). Decreasing the NaOH concentration required correspondingly longer incubation times. The potency of both toxins was also destroyed by incubation forlO-15 min at 500°C. Steam autoclaving 30 min at 122°C (18 psi) was not sufficient to detoxify brevetoxins. These results show that laboratory equipment will be decontaminated and rendered safe for normal handling by washing or soaking it in a dilute NaOH solution. Disposable waste can be either soaked in an NaOH solution prior to disposal or burned in an incinerator with a combustion chamber of at least 500°C. Steam autoclaving, however, is not a viable method of decontamination.
Liquid Chromatographic Determination of Lake Red C Amine and
2-Naphthol in D&C Red No. 8
Authors: Scher Alan L , Calvey Robert J 
Published: February 2020

Abstract
A method is described for the determination of the intermediates in D&C Red No. 8 by reverse-phase liquid chromatography (LC). The pigment is dissolved in boiling 95% ethanol-water (1 + 1) and then precipitated. The filtrate is chromatographed by gradient elution. Calibrations from peak areas at 254 nm for Lake Red C Amine sodium salt (LRCA-Na) and at 229 nm for 2-naphthol were linear, with prediction limits of 0.200 ± 0.006% and 0.200 ± 0.003%, respectively, for the maximum permitted levels. Calibration limits of determination were 0.01% for LRCA-Na and 0.006% for 2-naphthol. A 99% confidence level was used. Recoveries were 100.0-100.4% for LRCA-Na and 97.1-101.8% for 2-naphthol, each added at levels of 0.025-0.2%. Certified lots of D&C Red No. 8 that were analyzed by the LC method contained higher levels of LRCA-Na but the same levels of 2-naphthol when compared to results obtained previously by a cellulose column method, in which the pigment is not dissolved. The solubilities of D&C Red No. 8 in hot and room temperature solutions of 95% ethanol-water (1 + 1), water, and 95% ethanol were estimated.
Pesticide Residue Findings by the Luke Method in Domestic and Imported
Foods and Animal Feeds for Fiscal Years 1982-1986
Authors: Hundley, Harvey K , Cairns Thomas , Luke Milton A , Masumoto Herbert T 
Published: February 2020

Abstract
Nearly 20 000 samples of food and feed commodities were analyzed for pesticide residues by the U.S. Food and Drug Administration Los Angeles District Laboratory during the 5-year study period 1981- 1986. The resultant data base has been summarized to provide separate residue information for domestic and imported samples. The overall violation rates for domestic and imported samples collected on a surveillance basis were 3.0 and 2.6%, respectively. For domestic and imported samples collected on a compliance basis, the overall violation rates were 19.7 and 17.5%, respectively.
Quantitation of Ochratoxin A: Use of Reverse Phase Thin-Layer Chromatography for Sample
Cleanup Followed by Liquid Chromatography or Direct Fluorescence Measurement
Authors: Frohlich Andrzej A , Marquardt Ronald R , Bernatsky Aniko 
Published: February 2020

Abstract
An improved procedure for sample preparation and quantitation of ochratoxin A in moldy grain was developed. Grain samples were acidified and extracted, and extracts were subjected to reverse phase thin-layer chromatography (RPTLC). The separated spots, which were identified under UV light, were scraped and collected into recovery devices. Ochratoxin A was eluted from the adsorbent and analyzed by either liquid chromatography with fluorescence detection or direct spectrofluorometric measurement. The method yielded values that were proportional to the concentrations of toxin in the sample, had relatively high levels of recovery (94%), and required considerably less volume of solvents and preparation time than a standard packed column method.
Multitest System for Biochemical Identification of Salmonella, Escherichia coli, and Other Enterobacteriaceae Isolated from Foods: Collaborative Study
Authors: Keelan Susan L , Flowers Russell S , Robison Barbara J 
Published: February 2020

Abstract
Nine laboratories evaluated the ability of the MICRO-ID test system to correctly identify members of the Enterobacteriaceae. A total of 78 isolates representing 11 genera of enterics that had been previously isolated from foods were used in the collaborative study. The collaborators streaked each isolate on plate count agar and incubated the plates overnight at 35°C to check purity of the isolates. Then they proceeded with the method in which an isolated colony is transferred to a plate count agar slant and is incubated 18-24 h at 35°C. Growth from the slant is emulsified in 3.5 mL physiological saline to a density comparable to a McFarland No. 2 tube and is then used to inoculate the test (MICRO-ID) strip. The strip is incubated 4 h at 35°C and the reactions are read and recorded. Isolates are identified by using an octal code and the test kit manual. The system correctly identified 98.8% of the Salmonella isolates, 97.7% of the E. coli isolates, and 84.6% of the other 9 enteric genera tested. The system has been approved interim official first action as an alternative to conventional biochemical tests (1) for presumptive generic identification of foodborne Salmonella and for screening and elimination of non-Salmonella isolates; (2) for identification of E. coli from foods; and (3) for presumptive generic identification of other Enterobacteriaceae isolated from foods.
Gas Chromatographic Method for Determination of Fenitrothion in Fenitrothion Technical and in Formulated Products: Collaborative Study
Authors: Mount Dwight L , Churchill Frederick C 
Published: February 2020

Abstract
A gas chromatographic (GC) method for determination of fenitrothion in fenitrothion technical and formulated products has been subjected to a collaborative study with 7 participating laboratories. Formulations are extracted with chloroform containing dibutyl sebacate as an internal standard and are analyzed by gas chromatography using an OV-210 column. Collaborators were furnished matched pairs of technical product and water-dispersible powder and emulsifiable concentrate formulations. Relative standard deviations for reproducibility (RSDR) for the paired samples were 0.54, 1.00, and 1.56%, respectively, for technical fenitrothion, water-dispersible powders, and emulsifiable concentrates. The method has been approved interim official first action as an alternative to the present official first action AOAC method 6.A19-6.A24, which uses a polyphenyl ether, 6 ring (PPE-6R) column packing and fluoranthene as internal standard.
Application of ^-Nuclear Magnetic Resonance Spectroscopic Method for Quinidine to
Simultaneous Determination of Quinidine and Dihydroquinidine in Quinidine Sulfate Tablets
Authors: Hanna George M , Lau-Cam Cesar A 
Published: February 2020

Abstract
Based on the structural differences between quinidine and dihydroquinidine, a 'H-nuclear magnetic resonance spectroscopic method previously reported for quinidine drug substance was modified and shown to be applicable to the quantitative determination of both compounds in quinidine sulfate tablets. Deuterated chloroform was used as the solvent and hexamethylcyclotrisiloxane served as an internal standard. The average recovery and standard deviation of quinidine sulfate (calculated as the sum of quinidine sulfate plus dihydroquinidine sulfate) from synthetic formulations was 98.94 ± 0.43% (n = 10). Five lots of 200 mg tablets of quinidine sulfate from one commercial source were found to contain from 92.9 to 95.8% quinidine sulfate, and from 1.1 to 7.0% dihydroquinidine sulfate
Reverse-Phase Liquid Chromatographic Analysis of Cephalosporins
Authors: Ting Susan 
Published: February 2020

Abstract
A simple and rapid reverse-phase liquid chromatographic method was developed for the qualitative and quantitative analysis of 13 cephalosporin compounds. A mixture of cefaclor, cefadroxil, cefamandole nafate, cefamandole sodium, cefazolin, cefoperazone, cefotaxime, cefoxitin, ceftizoxime, cephalothin, cephalexin, cephapirin, and cephradine was resolved into its components in raw material and dosage form samples by using a Clg column, a methanol-water-acetic acid (30 + 70 + 0.1) mobile phase, and a UV detector set at 254 nm. The proposed method is suited both for the determination of cephalosporins in a wide variety of commercial dosage forms and for the investigation of related compounds and other impurities in samples of 7 of the cephalosporins
Spectrofluorometric Assay of Thiamine Hydrochloride in Injections and Multivitamin
Preparations
Authors: Mohamed Abdel-Maboud I , Hussein Samiha A , El-Shabouri Salwa R 
Published: February 2020

Abstract
A spectrofluorometric method is described for the determination of thiamine hydrochloride. The method is based on formation of a fluorescent product by oxidation of thiamine HC1 with 2,3,5,6-tetrabromo- l,4-benzoquinone in aqueous acetonitrile solution. The reaction product is stable for at least 6 h and shows excitation and emission maxima around 355 and 420 nm, respectively. The method is highly selective for thiamine HC1 in the presence of other B vitamins. Thiamine HC1 can be determined at concentrations as low as 20-160 ng/ mL of the final solutions. When the method was applied to the determination of thiamine HC1 added to some commercially available multivitamin preparations, recoveries were 98.78-99.98%
FDA Total Diet Study, April 1982-April 1984, Dietary Intakes of Pesticides, Selected
Elements, and Other Chemicals
Authors: Gunderson Ellis L 
Published: February 2020

Abstract
The U.S. Food and Drug Administration conducts the Total Diet Study to determine dietary intakes of selected pesticides, industrial chemicals, and elements (including radionuclides). The current study, which reflects significant redesign implemented in April 1982, involves retail purchase of foods representative of the "total diet" of the U.S. population, preparation for "table-ready" consumption, and individual analyses of 234 items depicting the diets of 8 population groups. The dietary revision was based on 2 nationwide food consumption surveys. The data presented represent 8 food collections (also termed "market baskets") in regional metropolitan areas during the 2-year period. Dietary intakes of over 100 analytes are presented for the 8 population groups, which range from infants to elderly adults. Intakes of selected population groups are compared with representative previous findings. As in the past, average daily intakes are within acceptable limits
Class Definition and Mixture Class Definition by Means of Construction of Convex Hull Boundaries: Application to Analysis for Animal Fat Adulteration
Authors: Thielemans Anne , Brabander Hubert De , Massart Desire L 
Published: February 2020

Abstract
A visual classification technique based on the construction of convex hull boundaries in combination with a principal component analysis is described. This combined technique was evaluated in the situation in which a distinction has to be made between 2 pure animal fat classes and the corresponding mixture class. In the first instance, a principal component analysis is carried out to ensure the 2-dimensional and thus visual aspect of the technique. Convex hulls are then constructed in the 2-dimensional principal component plane to delimit the boundaries of the different classes to be defined. The effectiveness of the constructed hull boundaries in the definition of class-membership was investigated by means of the classification of different simulated test samples. The results show that, at least for the tested applications, the technique is valid, although some false positive classifications occur. The detection of outliers especially seemed to pose problems. Therefore, some propositions are made of how to refine the developed hull technique to enhance the classification results.
Methods of Analysis for Toxic Elements in Food Products. 3. Limit of Determination of Methods for Assuring Safety
Authors: Skurikhin Igor M 
Published: February 2020

Abstract
To evaluate the suitability of the analytical methods used in determining food safety, a new metrological characteristic "MQS" is suggested. MQS is defined as the absolute minimum quantity in micrograms of a substance that can be determined in a test solution (solubilized test portion). MQS accounts for 2 factors: (a) the necessity for a reliable determination of ML (maximum permitted level, i.e., regulatory tolerance), and (b) the optimum quantity of test portion of a food product to be analyzed, and thus assists in evaluating the suitability of a method to assure food safety. The MQS of 8 toxic elements in any food are As, 3; Cd, 0.5; Cu, 20; Fe, 50; Hg, 0.2; Pb, 4; Sn, 200; Zn, 100fig. To characterize the applicability of any given method, the specific minimum limit of determination, MQSM, must be established for each method. The method in question may be used to control food safety only if MQSM is less than MQS. MQSM values are given for the common polarographic and colorimetric methods for determining these elements.
Immunodiffusion Screening Method for Detection of Motile Salmonella in Foods: Collaborative Study
Authors: Flowers Russell S , Klatt Mary Joan 
Published: February 2020

Abstract
A collaborative study was performed to validate the performance of the 1-2 TEST® for detection of motile salmonellae in foods. Detection is based on observation of an immobilized band of cells. Twentythree laboratories participated in the study. The 1-2 TEST (immunodiffusion test) was compared with the standard culture procedure (BAM/AOAC; FDA Bacteriological Analytical Manual) for detection of Salmonella in 6 food types: ground black pepper, soy flour, dried whole egg, milk chocolate, nonfat dry milk, and raw deboned turkey. Uninoculated and inoculated samples were included in each food group analyzed. After the tests on the 6 foods were completed, analysis of the data for turkey and soy flour showed that certain collaborators obtained data inconsistent with the data from the majority of collaborators. No specific method deviations to account for the inconsistencies were reported by those collaborators, so the collaborative testing of these 2 foods was repeated. Analysis of data for pepper, chocolate, nonfat dry milk, dried whole egg, and the second set of soy flour and turkey indicated 96.1% agreement between the BAM/AOAC and immunodiffusion test methods. The false negative rates for the immunodiffusion test and BAM/AOAC methods were 3.6 and 1.7%, respectively. There was no significant difference in the productivity of the immunodiffusion test and BAM/AOAC method at the 5% level for any of the 6 foods. The immunodiffusion screening method has been approved official first action for detection of motile Salmonella in food
Purification of Cyclopiazonic Acid by Liquid Chromatography
Authors: Peterson Robert E , Shannon Gail M , Shotwell Odette L 
Published: February 2020

Abstract
A purification procedure for cyclopiazonic acid has been developed, using sequential preparative and semi-preparative liquid chromatography. Crude cyclopiazonic acid (324 mg) was extracted from a 1 L fermentation medium with chloroform-methanol (80 + 20), dried, dissolved in chloroform, and chromatographed on an oxalic acid/ silica preparative column with chloroform-methanol (99 + 1) as the eluant. A semi-preparative oxalic acid/silica column and chloroform- methanol (99.5 + 0.5) were then used for rechromatography of the partially purified cyclopiazonic acid. This second chromatographic treatment yielded fractions from which cyclopiazonic acid was readily crystallized (106.7 mg; 33% recovery). Analytical chromatography was developed using an amino column in an ion-exchange mode, with a methanol-phosphate buffer eluant. Response was linear from 10 to 800 μg/injection of standard solutions. Cyclopiazonic acid chemically binds sodium from soda-lime vials.
Liquid Chromatographic Determination of Aflatoxins, Ochratoxin A, and Zearalenone in Grains, Oilseeds, and Animal Feeds by Post-Column Derivatization and On-Line Sample Cleanup
Authors: Chamkasem Narong , Cobb William Y , Latimer George W , Salinas C , Clement B A 
Published: February 2020

Abstract
A liquid chromatographic method using on-line sample cleanup, reverse flow analytical column loading, gradient elution, and postcolumn derivatization with iodine permits direct, rapid determination of aflatoxins B1, B2, G1, and G2, as well as ochratoxin A and zearalenone. Limits of quantitation are 5 ppb for the aflatoxins and ochratoxin A and 30 ppb for zearalenone. This procedure performs well as a multimycotoxin screen for cereal grains and oilseeds, with more limited success in complete animal feeds.