bluuebunny/crossref_metadata_2025_split huggingface dataset:
Liquid Chromatographic Determination of a-Zearalenol and Zearalenone in Corn: Collaborative Study
Authors: Bennett Glenn A , Shotwell Odette L , Kwolek William F 
Published: February 2020

Abstract
The liquid chromatographic determination of a-zearalenol and zearalenone in corn was collaboratively studied. Each of 13 collaborators received 7 corn samples; 2 were blanks and 5 were spiked to contain 50, 100, and 200 ng α-zearalenol/g and 50, 100, 500, 1000, and 4000 ng zearalenone/g. Four sets (including blanks) of blind duplicates were included in the study. Five naturally contaminated corn samples (one in duplicate) were also provided. AH collaborators detected both mycotoxins at 50 ng/g. Average recoveries reported by all collaborators ranged from 81.9% at 200 ng/g to 100.3% at 50 ng/g for a-zearalenol and from 77.8% at 1000 ng/g to 123% at 50 ng/g for zearalenone. Three collaborators reported false positives for both a-zearalenol and zearalenone. The within-laboratory CV values based on blind duplicates were 22.6% for α-zearalenol and 31.4% for zearalenone. The CV values based on laboratory-sample interaction were 25.6 and 33.8% for α-zearalenol and zearalenone, respectively. The CV values for naturally contaminated samples (including duplicates) were 47.0% for a-zearalenol and 37.7% for zearalenone. The method has been adopted official first action.
National Bureau of Standards Reference Materials as Organic Nutrient Standards: A Preliminary Study
Authors: Tanner James T , Smith Jeffrey S , Angyal Gerald , Defibaugh Phillip W , Villalobos Melina C , Bueno Martin P 
Published: February 2020

Abstract
A preliminary study was conducted to determine if the available National Bureau of Standards (NBS) Standard Reference Materials (SRM) Non- Fat Powdered Milk, Oyster Tissue, Wheat Flour, Rice Flour, Spinach, and Albacore Tuna would be suitable for use as organic nutrient standards. These materials were assayed for folates, total pantothenates, vitamin B6, thiamine, riboflavin, niacin, and protein. Vitamins A, E, D, K, and C were also assayed but, for the most part, were not detected. Based on results from this study, it appears that at least some of the NBS SRMs would be useful as organic nutrient standards.
Purge and Trap Method for Determination of Ethylene Dibromide in Whole Grains, Milled Grain Products, Intermediate Grain-Based Foods, and Animal Feeds
Authors: Heikes David L 
Published: February 2020

Abstract
An improved method has been developed for the determination of ethylene dibromide (EDB; 1,2-dibromoethane) in whole grains, milled grain products, intermediate grain-based foods, and animal feeds. Samples are mixed with water and sparged with nitrogen for 1 h with stirring in a water bath at 100°C. The EDB collected on the adsorbent Tenax TA is eluted with hexane and determined by gas chromatography (GC) with electron capture detection (ECD) and confirmed with Hall electrolytic conductivity detection (HECD) using a second GC column. The highest levels of EDB were also confirmed by full scan GC/mass spectrometry (GC/MS). A total of 24 whole grains, milled grain products, intermediate grain-based foods, and animal feeds analyzed by using this method contained EDB levels up to 840 ppb (wheat). Recoveries from fortified samples ranged from 90 to 105%. Values from this method were compared with those obtained from the acetone soak method; for all 24 samples, this purge and trap method gave equivalent or superior recoveries and detected levels of EDB. Chromatograms for this purge and trap method were clean, enabling a quantitation level of 0.5 ppb to be achieved.
Simultaneous Liquid Chromatographic Determination of Warfarin and Sulfaquinoxaline in Cornmeal-Based Rodenticide
Authors: Akhtar Selina , Bailey Leonard C 
Published: February 2020

Abstract
A method is reported for the simultaneous determination of warfarin and sulfaquinoxaline in a cornmeal-based commercial rodenticide by extraction of the 2 components with acetonitrile followed by liquid chromatographic separation. A reverse phase C-18 column is used with a simple buffered mobile phase (acetonitrile-water (50 + 50) 0.005M inheptanesulfonic acid sodium salt, pH 3.5) that elutes sulfaquinoxaline as a paired-ion and warfarin as an ion-suppressed non-ionic species. The 2 compounds are detected at 280 nm after separation and are quantitated using ethyl p-nitrobenzoate as an internal standard. The method compares favorably with existing methods of analysis for the 2 compounds in terms of accuracy and precision, and is superior to those methods in speed as well as specificity.
Pesticides, Selected Elements, and Other Chemicals in Infant and Toddler Total Diet Samples, October 1979-September 1980
Authors: Gartrell Marcia J , Craun John C , Podrebarac David S , Gunderson Ellis L 
Published: February 2020

Abstract
The U.S. Food and Drug Administration (FDA) conducts Total Diet Studies to determine the dietary intake of selected pesticides, industrial chemicals, and elements (including radionuclides). These studies involve the retail purchase and analysis of foods representative of the diets of infants, toddlers, and adults. The individual food items are separated into a number of food groups, each of which is analyzed as a composite. This report summarizes the results for infant and toddler Total Diet samples collected in 10 cities between October 1979 and September 1980. The average concentration, range of concentrations, and calculated average daily intake of each chemical found are presented by food group. The average daily intakes of the chemicals are similar to those found in the several preceding years and generally are within acceptable limits. The results for samples collected during the same period that represent the adult diet are reported separately.
Amperometric Determination of Phenazopyridine Hydrochloride in a Flowing Stream at the Glassy Carbon Electrode
Authors: Belal Fathalla 
Published: February 2020

Abstract
A flow-injection method is described for the determination of phenazopyridine hydrochloride, based on electrochemical oxidation at the glassy carbon electrode. The suggested method is highly specific and can be used to determine phenazopyridine HC1 in the presence of most drugs commonly found in pharmaceutical dosage forms or administered therapeutically. Applying a constant potential of +950 mV vs Ag/AgCl/3.5M KCI reference electrode, the calibration curve was linear in the 1-30 μg/mL range, with minimum detectability of 0.2 ng (signal-to-noise ratio 2). Good accuracy and precision were obtained when the method was applied to some dosage forms containing phenazopyridine HC1. Although automation was not used in this study, an automated system could be incorporated because the method uses the technique of continuous analysis in a flowing stream.
Electron Capture Gas Chromatographic Determination of Thiabendazole in Yams
Authors: Bardalaye Promode C , Wheeler Willis B 
Published: February 2020

Abstract
A method for the determination of thiabendazole in yams is reported. The method consists of extracting the chopped crops with ethyl acetate followed by distilled water wash and liquid liquid extraction of the chemicals into dilute hydrochloric acid. The sample is further cleaned up by making the aqueous acidic fraction alkaline and repartitioning into ethyl acetate. The determination step includes evaporation of the cleaned up extract to dryness, derivatization with pentamiorobenzoyl chloride, and determination of the derivatized thiabendazole in acetone by gas chromatography with electron capture detection.
Pesticides, Selected Elements, and Other Chemicals in Infant and Toddler Total Diet Samples, October 1980-March 1982
Authors: Gartrell Marcia J , Craun John C , Podrebarac David S , Gunderson Ellis L 
Published: February 2020

Abstract
The U.S. Food and Drug Administration (FDA) conducts Total Diet Studies to determine the dietary intake of selected pesticides, industrial chemicals, and elements (including radionuclides). These studies involve the retail purchase and analysis of foods representative of the diets of infants, toddlers, and adults. The individual food items are separated into a number of food groups, each of which is analyzed as a composite. This report summarizes the results for infant and toddler Total Diet samples collected in 13 cities between October 1980 and March 1982. The average concentration, range of concentrations, and calculated average daily intake of each chemical found are presented by food group. The average daily intakes of the chemicals are similar to those found in the several preceding years and generally are within acceptable limits. The results for samples collected during the same period that represent the adult diet are reported separately.
Ion Chromatographic Determination of Sulfites in Foods
Authors: Anderson Courtney , Warner Charles R , Daniels Daniel H , Padgett Kathlene L 
Published: February 2020

Abstract
Ion chromatography (IC) is shown to be a promising technique for the determination of sulfites (SO2, SO⅔) in foods. Results of a 10 min flash distillation and 10 min IC determination compare favorably with the results from the conventional Monier-Williams method for total sulfite in a variety of food matrices. The IC technique also provides a wealth of additional information, such as (1) sulfite and sulfate (oxidized sulfite) content of the spiking or treatment solution, (2) residual sulfite applied to the food after oxidation losses in the treatment process, (3) free sulfite in foods, and (4) total sulfite in foods. As a further check on the Monier-Williams method, the sulfate content of the trapping solution can be determined by IC. Because the IC technique traps the liberated SO2 in a non-oxidizing rather than an oxidizing medium, it is considered free from interfering sulfides and organic sulfur-containing groups which can give false positives in the Monier-Williams method. IC thus offers a high speed, more sensitive, and cost-effective alternative to conventional techniques for the determination of sulfite in foods.
Liquid Chromatographic Determination of Identity, Content, and Content Uniformity of Desipramine, Fluphenazine, and Promazine
Authors: Beaulieu Normand , Gagné Charles , Lovering Edward G 
Published: February 2020

Abstract
A liquid chromatographic procedure has been developed for the assay, content uniformity, and identification of single active ingredient formulations of desipramine, fluphenazine, and promazine. The drugs are extracted from formulations with methanol or dilute hydrochloric acid and quantitated against an internal standard (norephedrine). The drugs are identified by comparison of retention times with those of the reference standards.
Determination of Oxytetracycline in Premixes and Veterinary Products by Liquid Chromatography
Authors: Chappell Gary S , Houglum Joel E , Kelley Wesley N 
Published: February 2020

Abstract
A liquid chromatographic method for the assay of oxytetracycline in premixes and veterinary products is described. Premix samples are extracted with acidified methanol, diluted with mobile phase, and filtered before chromatography on a C-8, reverse phase .column. The assay method separates oxytetracycline from epioxytetracycline, tetracycline, and chlortetracycline. Total elution time for oxytetracycline is less than 5 min at 1.5 mL/min. Five spiked premix samples each of 2 and 50 g/lb had a coefficient of variation of 3.5 and 4.5% and a mean recovery of 99 and 104%, respectively. The results of premixes and veterinary products assayed by this method compared closely with those of the same samples assayed by the official AOAC microbiological method.
Reevaluation of Monier-Williams Method for Determining Sulfite in Food
Authors: Warner Charles R , Daniels Daniel H , Joe Frank L , Fazio Thomas 
Published: February 2020

Abstract
The Monier-Williams distillation procedure has a long history of successful use for determining sulfite in fruit products and wine; however, a systematic evaluation of its accuracy and precision with other food matrices has not been undertaken. We found that the Monier-Williams distillation yielded &gt;90% recovery of sulfite added to foods such as table grapes, hominy, dried mangoes, and lemon juice. Less than 85% recovery was obtained with broccoli, soda crackers, cheese-peanut butter crackers, mushrooms, and potato chips. These results may, in fact, accurately reflect the residual levels of sulfite if a portion of the sulfite undergoes irreversible reaction with some food components. Analysis of commercial food products gave sulfite levels ranging from 1400 ppm in dried apple slices to 25 ppm in cream sherry
Gas Chromatographic Analysis of Milk for Deoxynivalenol and Its Metabolite DOM-1
Authors: Swanson Steven P , Dahlem Andrew M , Rood Harold D , Côte Louis-Marie , Buck William B , Yoshizawa Takumi 
Published: February 2020

Abstract
A gas chromatographic method is described for the determination of deoxynivalenol (DON) and its metabolite DOM-1 in milk. Milk samples were extracted with ethyl acetate on a commercially available disposable extraction column, followed by hexane-acetonitrile partitioning. Final purification was accomplished on a reverse phase C-18 cartridge. The trimethylsilyl ether (TMS) derivatives of DON were prepared, chromatographed on an OV-17 column, and quantitated with an electron capture detector. Chromatography of the TMS derivatives of milk extracts was compared to that of the corresponding heptafluorobutyryl derivatives. The limit of detection using TMS derivatives was 1 ng/mL for both toxins with recoveries averaging 82% ± 9% at 2.5 and 10 ng/ mL milk for DON and 85% ± 6% at 10 ng/mL for DOM-1.
Titrimetric Determination of Vitamin B6 Using Chloramine-T, Bromamine-T, and Bromamine-B
Authors: Jayaram Beby , Gowda Netkal M Made 
Published: February 2020

Abstract
Simple titrimetric methods have been developed for determination of the vitamin pyridoxine (PRX) in solution, using aromatic N-haloamines, chloramine-T, bromamine-T, and bromamine-B. The method is based on oxidation of PRX by the N-haloamines; the oxidation involves a 2-electron change. The reaction products, pyridoxal and sulfonamides, were identified. The effects of variables, such as pH of the medium and the presence of foreign ions, and pyridoxal, pyridoxalamine, glycerol, and alcohol, on the rate of oxidation were studied. The methods are useful for determining PRX in pharmaceutical formulations and for assaying its cadmium complex. Statistical evaluation showed that analytical results are accurate to within 1%.
Simple Colorimetric Method for Determination from Pharmaceutical Preparations
Authors: Sane Ramesh T , Malkar Vishwanath B , Nayak Vinay G , Sapre Dhananjay S 
Published: February 2020

Abstract
A simple colorimetric method is described for the determination of terbutaline sulfate. The method is based on measurement of a colored species formed when terbutaline sulfate is treated with diazotized dapsone and p-nitroaniline at room temperature. Compounds such as starch, talc, and common excipients do not interfere in the reaction. Statistical validation showed that the method was highly precise and accurate. The results agree well with those obtained by other methods reported in the literature.
Rapid and Simple Determination of Oxyphenbutazone in Dosage Forms by Biamperometric Titration
Authors: Šebková Daniela , Šafařík Luděk 
Published: February 2020

Abstract
Oxyphenbutazone was determined in the presence of glacial acetic acid, hydrochloric acid, and potassium bromide by bromometric titration with biamperometric end point indication. The course of the titration was followed with double platinum electrode with 100 mV of polarizing voltage
Parameters and Definitions in Harmonization of Collaborative Analytical Studies
Authors: Parkany M 
Published: February 2020

Abstract
IUPAC, AOAC, and ISO participate in developing, validating, and adopting analytical methods for international use. Harmonization of the different interests of these organizations is desirable, as is harmonization of parameters of precision of test methods. ISO Technical Committee 69 is responsible for standards that deal with statistical interpretation of test results and data, sampling procedures, and precision of test methods.
Analytical Quality Control in United Kingdom Water Industry, with Particular Reference to Harmonized Monitoring Scheme for River Water Quality
Authors: Tetlow J A , Hunt D T E 
Published: February 2020

Abstract
The development of river water quality monitoring in the United Kingdom and the parallel development of analytical quality control (AQC) procedures within the UK water industry are described. Some results are presented for a sequential scheme of AQC which seeks to ensure comparability of analytical results obtained by different laboratories. The problems and advantages of such a scheme are examined, and future developments in nationally coordinated AQC in the water industry are discussed.
Improved Spray Reagent for Thin Layer Chromatographic Method for Detecting Uric Acid: Collaborative Study
Authors: Ferrera Robert S , Boese Jack L , Thrasher Joel J 
Published: February 2020

Abstract
A collaborative study was conducted to validate the substitution of an improved single spray in the official AOAC thin layer chromatographic method for identifying uric acid (UA) from bird and insect excreta. The proposed reagent, which is a dilute aqueous solution of ferric chloride and potassium ferricyanide, requires neither a heating step nor a pH indicator. Its preparation time, specificity, and sensitivity to low levels (5-50 ng) of UA were compared with those of the official sprays. The improved spray took 1/5 as long to prepare as the official sprays. Neither the proposed spray nor the official sprays gave false positive reactions with compounds similar to UA. For bird and insect excreta samples, at the 95% confidence limits, the false negative rate was between 0 and 9.7% for the proposed spray and between 0.7 and 18.7% for the official sprays. Sensitivity results showed that the proportion positive for the proposed spray was significantly higher (P&lt;0.05) than for the official sprays at the 15 ng UA level. The proposed changes have been adopted official first action.
Liquid Chromatographic Determination of Hydrazine in Polyvinylpyrrolidone
Authors: Matsui Fumiko , Sears Roger W , Lovering Edward G 
Published: February 2020

Abstract
A liquid chromatographic method for determination of hydrazine in polyvinylpyrrolidone (PVP) has been developed. After PVP is dissolved in acetate buffer, hydrazine is derivatized with benzaldehyde to form benzalazine, and is quantitated on a silica column using p-dinitrobenzene as the internal standard. The minimum quantitatable level of hydrazine is about 180 ppb, but with changes in the sampling procedure, this could readily be lowered to 90 ppb. Reproducibility on repeat analysis is about ± 10%. The method was used to analyze 16 lots of PVP from 3 commercial sources. Results ranged from nondetectable to 11 600 ppb; recoveries from spiked samples in most cases were 84% or better. Hydrazine levels tended to be lower in the higher molecular weight samples.
Chemical Derivatization Analysis of Pesticide Residues. X. Analysis of Ten Acid Herbicides in Natural Waters
Authors: Lee Hing-Biu , Stokker Yvonne D , Chau Alfred S Y 
Published: February 2020

Abstract
An improved and augmented gas chromatographic (GC) method using a capillary column and electron capture detector was developed for determination of 10 common acid herbicides in natural water. The herbicides were extracted with methylene chloride after the water sample was acidified to pH &lt; 1. Concentrated extracts in acetone were derivatized with pentafluorobenzyl bromide (PFBBr) to form the corresponding PFB esters. Derivatives were cleaned up on a deactivated silica gel column. A SE-54 fused silica capillary column was used to separate and identify the products. Using this procedure, the method was successfully validated for herbicide concentrations as low as 0.05 μg/L in natural waters. Recoveries of water samples fortified with the 10 herbicides ranging from 1.0 to 0.05 μg/L were 73 to 108% with the exception of picloram which was only 59% recovered at 0.1 μg/L.
Derivative Spectrophotometric Determination of Some Corticosteroids in Combinations with Other Drugs
Authors: El-Yazbi Fawzy A , Korany Mohamed A , Abdel-Razak Omayma , Elsayed Mahmoud A 
Published: February 2020

Abstract
Three 2-component mixtures, namely, dexamefhazone-chlorpheniramine maleate, prednisolone-chlorpheniramine maleate, and prednisolone-salicylic acid, have been assayed using their first (D1,) and second (D2) derivative spectra in methanol, delta absorption (ΔA), and second derivative of Δ A (Δ D2) spectra in methanol-methanolic HC1. In the first 2 mixtures, chlorpheniramine maleate was determined by measuring its Δ D2 value at 278 nm, while dexamethazone and prednisolone were analyzed by measuring their D1 values at 248 nm. Prednisolone and salicylic acid were analyzed in combination by using their respective D2 spectral responses at 272 and 314 nm. The results obtained are reasonably reproducible with a relative standard deviation &lt;2%. The method has been successfully applied to the analysis of these drugs in their pharmaceutical formulations.
Rapid Quantitative Thin Layer Chromatographic Screening Procedure for Sulfathiazole Residues in Honey
Authors: Neidert Eli , Baraniak Zig , Sauvé André 
Published: February 2020

Abstract
A procedure is presented for the quantitative determination of sulfathiazole residues in honey. Induced fluorescence of sulfathiazole is measured by fluorescent scanning densitometry; sulfaquinoxaline is added as an internal standard for quantitation. Recovery is greater than 98% and results are linear over the range 0.05-0.60 mg/kg. The detection limit, CL (k = 3), is 0.02. The procedure allows a single analyst to process 50-60 samples/day.
Detection of Beet Sugar Adulteration of Honey
Authors: White Jonathan W , Meloy Robert W , Probst Jerry L , Huser William F 
Published: February 2020

Abstract
Quantitation of oligosaccharide-bound galactose by galactose oxidase treatment of the higher sugar fraction is useful to screen honeys with normal stable carbon isotope ratio values for the presence of beet sugar products. For 23 beet sugar products tested, the mean bound galactose value was 30.1 mg/100 g (as galactose); for 81 honeys, the mean was 3.1 mg/100 g, s = 4.4. Nine percent of the honey samples tested had values in the beet sugar range, so additional testing by other procedures is required for confirmation of adulteration, i.e., samples with 8-80 mg/100 g bound galactose should be further tested.
Automated Determination of Ethanol and Wine Extract with Precision Density Meter, Automatic Sampler, and Programmable Calculator
Authors: Ruppert Jerry R 
Published: February 2020

Abstract
Use of density meters has become the preferred method in many alcohol beverage laboratories to determine the concentration of ethanol in wines and spirits. Density converted to SG (20/20) is also the basis of an official AOAC method to determine extract of wine. Automation of the latter procedure is inhibited by the necessity to access AOAC Table 52.008 to convert SG (20/20) of the dealcoholized wine sample to percentage of sucrose by weight. The author reduced the most commonly used portion of that table (1-30% sucrose by weight) to a third degree polynomial, enabling the use of a density meter, an automatic sampler, and a computer or programmable calculator to automatically determine alcoholic content and wine extract from a sample of wine and its distillate. The absolute error between AOAC Table 52.008 and the author’s polynomial equation is less than ± 0.002 percentage of sucrose by weight for the range 1-30% sucrose by weight.