bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation of Reference Water and Soil Samples for Performance Evaluation of Volatile Organic Analysis
Authors: Maskarinec Michael P , Johnson Lynne H , Bayne Charles K
Published: February 2020

Methodology was developed to reproducibly prepare performance evaluation materials for volatile organics analysis in soils and waters. Tedlar gas sampling bags are used to prepare the volatile organics spike solutions. The bags allow large volumes of sample or spike solution to be prepared to a high degree of homogeneity while using less methanol. Preparation of a large volume of sample or spike solution allows for increased accuracy of fortification. The accuracy is generally ±20% or better, and the precision is generally ±10% or better for water samples. The precision for preparation of soil samples is also good, but the accuracy suffers from variable recovery efficiencies from the soils. Most volatile organics were well preserved in 3 water samples by storage at refrigerator temperature for 14 days.
Comparison of AOAC and ISO Methods for Extraction of Water-Soluble Phosphates in Fertilizers
Authors: Farley James A
Published: February 2020

A wide range of phosphate fertilizers were analyzed for watersoluble phosphorus to compare 2 recognized methods: AOAC method 2.040 and the International Organization for Standardization (ISO) method No. 5316. In general, the ISO method extracted more phosphorus from triple and normal superphosphates; the AOAC method extracted more phosphorus from diammonium, monoammonium, and nitric phosphates. Both methods exhibited similar precision. The results indicate that care must be exercised when data for watersoluble phosphate are reported.
Enzyme-Linked Immunosorbent Assay of Aflatoxins Bi, B2, and Gi in Corn, Cottonseed, Peanuts, Peanut Butter, and Poultry Feed: Collaborative Study
Authors: Trucksess Mary W , Stack Michael E , Nesheim Stanley , Park Douglas L , Pohland Albert E
Published: February 2020

A direct competitive enzyme-linked immunosorbent assay (ELISA) screening method for aflatoxins at 20 ng/g was studied by 12 collaborators. Test samples of peanut butter were extracted by blending with methanol-water-hexane (55 + 45 + 100) and heating the test extracts on a steam bath; test samples of the other commodities were extracted by blending with methanol-water (80 + 20). All test extracts were filtered and the filtrates were diluted with buffer to a final methanol concentration of <30%. Each diluted filtrate was applied to a cup containing a filter with immobilized polyclonal antibodies specific to aflatoxins B1, B2, and G1. Aflatoxin B1-peroxidase conjugate was added, the cup was washed with water, and a mixture of hydrogen peroxide and tetramethylbenzidine was added. The test sample was judged to contain >20 ng aflatoxins/g when, after exactly 1 min, no color was observed on the filter; when a blue or gray color developed, the test sample was judged to contain <20 ng aflatoxins/g. All collaborators correctly identified naturally contaminated corn and raw peanut positive test samples. No false positives were found for controls containing <2 ng aflatoxins/g. The correct responses for positive test samples spiked at levels of 10, 20, and >30 ng aflatoxins/g (the ratio of B1, B2, and G1 was 10:1:3) were 52, 86, and 96%, respectively. The method, which is rapid and simple, has been adopted official first action for screening for aflatoxins at >20 ng/g in cottonseed and peanut butter and for aflatoxins at >30 ng/g in corn and raw peanuts. The procedure will require further study for poultry feed. Positive test samples may require reanalysis by an official, quantitative method.
Chemical Derivatization Analysis of Phenols. Part VI. Determination of Chlorinated Phenolics in Pulp and Paper Effluents
Authors: Lee Hing-Biu , You Hong R L , Fowlie P J A
Published: February 2020

Based on the in-situ acetylation procedure, a method for the determination of 31 chlorinated phenols, guaiacols, catechols, syringols, and vanillins in pulp and paper effluent samples has been successfully developed. Except for 4-chlorocatechol, this procedure provided satisfactory recovery for all phenols at 3 levels of fortification, namely, 400, 40, and 4 μg/L. The acetyl derivatives were analyzed by gas chromatography using a 30 m DB-5 capillary column interfaced to an electron-capture detector. Mass spectral abundance data for the characteristic ions of the acetyl derivatives were used for confirmation of compound identities. By operating a mass selective detector in the selected ion monitoring mode, this procedure was further extended to the monochlorinated phenolics. Using a 50 mL effluent sample, the method detection limit was 0.5 μg/L for all except the monochlorinated compounds, which had a detection limit of 1 μg/L. Several effluent samples from a Canadian paper mill were analyzed by this procedure and the results are presented.
Determination of Daminozide in Apples by Gas Chromatography /Chemical Ionization Mass Spectrometry
Authors: Liu Chao-Hong , Mattern Gregory C , Singer George M , Rosen Joseph D
Published: February 2020

A method using gas chromatography/chemical ionization mass spectrometry (GC/CIMS) for the determination of daminozide residues in apples has been developed. Daminozide was separated from the sample matrix by water extraction and cation exchange, converted to the methyl ester by treatment with HCl-methanol, and determined by GC/CIMS using succinonitrile as an internal standard. The detection level was 0.05 ppm. Recoveries were 92-104% from apples spiked at the 0.05-0.5 ppm levels. Of the 25 apple samples analyzed, only 2 were positive for daminozide (1.04 and 0.32 ppm).
Determination of Copper, Iron, and Nickel in Oils and Fats by Direct Graphite Furnace Atomic Absorption Spectrometry: Summary of Collaborative Study
Authors: Capar Stephen G
Published: February 2020

A collaborative study of a method for the determination of copper, Iron, and nickel in edible oils and fats by direct graphite furnace atomic absorption spectrometry was recently conducted by the International Union of Pure and Applied Chemistry. The quantitation limits of the method are 5 μg/kg for copper and 10 μg/kg for iron and nickel. The method has been adopted official first action as an IUPACAOAC method.
Adsorption of Aqueous Nonylphenol Ethoxylate Surfactants on Metal Sample Loops: Effect on Quantitation by Liquid Chromatography
Authors: Sithole B B , Zvilichovsky B , Lapointe C , Allen L H
Published: February 2020

In aqueous solutions of Igepal CO 610, a nonionic nonylphenol ethoxylate surfactant, adsorption of the surfactant takes place onto stainless steel metal surfaces. This adsorption results in increased peak height of the surfactant when a sample loop is purged with increasing volumes of the surfactant. This, in turn, affects the quantitation of the surfactant. However, the adsorption is reproducible at constant purging volumes and results in calibration curves with good precision.
Rapid Analysis of Nutritionally Important Free Amino Acids in Serum and Organs (Liver, Brain, and Heart) by Liquid Chromatography of Precolumn Phenylisothiocyanate Derivatives
Authors: Sarwar Ghulam , Botting Herbert G
Published: February 2020

An amino acid analysis method for protein hydrolysates, using precolumn phenylisothiocyanate (PITC) derivatlzatlon and liquid chromatography, was modified for its application In rapid analysis of commonly occurring free amino acids in serum and other physiological samples. The modifications Included changes In column temperature (47.5°C compared to 25-35°C used In analyzing protein hydrolysates), method of preparing standard and test samples, and gradient conditions. By using a Waters Pico-Tag amino acid analysis 15 cm long column (which Is also used for analyzing protein hydrolysates), separation of 27 PTC-amino acids in human serum and rat liver, brain, or heart was completed in 20 mln by the modified method. The total time for analysis and equilibration was 30 mln. The modified method was much faster than the traditional ion-exchange methods (2-3 h) or the existing liquid chromatographic methods using PITC derivatlzatlon (66-80 mln) for determining nutritionally Important free amino acids In physiological fluids and tissues. Variability of the method (expressed as coefficients of variation) for the determination (Including deprotelnizatlon, derivatlzatlon, and liquid chromatography) of all amino acids was less than 5%, which compared favorably with the reproducibility of Ion-exchange methods
Comparative Evaluation of Commercially Available Aflatoxin Test Methods
Authors: Koeltzow Donald E , Tanner Steven N
Published: February 2020

Five qualitative methods and 1 quantitative aflatoxin analytical method were compared with the Holaday-Velasco (HV) mlnlcolumn and thin-layer chromatography (TLC) methods for corn In an evaluation Involving 4 U.S. Department of Agriculture Federal Grain Inspection Service (USDA-FGIS) laboratories, 1 laboratory at the University of Georgia, and 1 laboratory at the University of Arizona. Samples analyzed Included 1 set of artificially contaminated corn containing both aflatoxin B1 and B2 (ratio of B1:B2 of 92:8), 1 set of artificially contaminated corn containing only aflatoxin B1t and 1 set of naturally contaminated corn. Levels of total aflatoxin tested were 0, 10, 15, 20, 25, 30, and 40 ppb. Results of analysis of these samples with each method evaluated are reported. Chl-square analyses Indicated that performance of the Afla-20-Cup, Aflatest, EZ-Screen, OXOID, and SAM-A methods was not statistically different from that of the HV mlnlcolumn. Agri-Screen results were not statistically different from those obtained with TLC.
Validation of a Method for Determination of Tetracycline Antibiotics in Salmon Muscle Tissue
Authors: Reimer Gerry J , Young Larry M
Published: February 2020

A method was validated for analysis of oxytetracycllne (OTC), tetracycline (TC), and chlortetracycllne (CTC) In fortified salmon muscle tissue. Recoveries of OTC were 100 ± 6, 86 ± 6, and 82 ± 5% (n = 6) at fortification levels of 1.0, 0.5, and 0.2 ppm, respectively. Recoveries of TC were 68 ± 4, 65 ± 6, and 66 ± 7%; recoveries of CTC were 45 ± 9,48 ± 8, and 0%, respectively. Detection limits for OTC and TC were 0.08 and 0.09 ppm, respectively
Comparison of Liquid Chromatographic Methods for Determination of Cis-Trans Isomers of β-Carotene
Authors: O'Neil Constance A , Schwartz Steven J , Catignani George L
Published: February 2020

Four liquid chromatographic columns and various solvent systems were evaluated for their ability to resolve and quantitate cls-trans Isomers of β-carotene. The Vydac C18 201 TP and Ca(OH)2 columns were most effective in resolving alltrans-, 13-cls-, and 9-cls-β-carotenes. Additionally, the 15- c18 Isomer was separated using the method employing a Ca(OH)2 column. Peak Identification was based on absorption spectra (obtained from photodlode array data), retention times, and coelutlon in comparison to authentic standards. A quantitative analysis of vegetable extracts using both the Vydac and Ca(OH)2 columns showed comparable results. However, both procedures lacked complete resolution of 2 minor clsβ-carotenes, tentatively identified as dl-cis Isomers. High selectivity for carotene Isomers as well as fewer interferences were observed with the Ca(OH)2 procedure for analysis of plant tissue extracts and thus, It is preferred for determination of β-carotene cis-isomer content In these samples.
Spectrophotometric Determination of Diethylpropion Hydrochloride Bulk Drug and Tablets in the Presence of Its Degradation Products
Authors: Saleh Gamal A
Published: February 2020

The charge transfer complex formation between diethylpropion and iodine was investigated and used as the basis for a simple and sensitive spectrophotometric method for diethylpropion and Its dosage forms. The solution exhibited blueshifted iodine bands at 295 and 365 nm. A Job's plot Indicated a 1:1 complexatlon ratio. At 295 nm, the absorbance was linear (r = 0.9995) over the 0.2-2.4 μg/mL concentration range. The method has been applied successfully to the analysis of commercially available diethylpropion hydrochloride tablets without interference from thiamine hydrochloride, pyridoxine hydrochloride, nicotinamide, and riboflavin. Interference from the degradation products 1-phenyl-1,2- propanedione and diethylamine was avoided. Molar absorptivity, association constant, and free energy change were investigated further.
Determination of Carbadox-Related Residues in Swine Liver by Gas Chromatography/Mass Spectrometry with Ion Trap Detection
Authors: Lynch Martin J , Mosher Franklyn R , Schneider Richard P , Fouda Hassan G , Risk James E
Published: February 2020

The Ion trap detector (ITD), in combination with a capillary gas chromatograph and under chemical ionization conditions, offers sufficient sensitivity to determine carbadoxrelated residues as the methyl ester derivative of quinoxaline- 2-carboxylic acid at 3 μg/kg or higher in porcine liver. A tetradeuterated internal standard of QME effectively compensates for losses incurred during sample preparation. The method produced mean levels of 3.3 (±0.5), 5.5 (±0.8), and 10.1 (±0.9) μg/kg for liver fortified at 3, 5, and 10 μg/kg. When applied to analysis of samples containing incurred residues of 14C-carbadox at the low μg/kg level, results were comparable to those obtained by reverse isotope dilution analysis.
A Rapid Method for the Determination of Chlorine, Phosphorus, and Sulfur in Flours of Grains and Legumes Using Wavelength Dispersive X-Ray Flourescence Spectrometry
Authors: Ruiz Tomás Pérez , Córdoba Manuel Hernández , González Roque Ortiz
Published: February 2020

A rapid method for the determination of chlorine, phosphorus, and sulfur In commercial flours of wheat, barley, maize, rice, field bean, and soybean by wavelength dispersive x-ray fluorescence spectrometry has been developed. The flours are strained through a 425 μm sieve, then pelletized and measured. The total analysis time for the quantitation of chlorine, phosphorus, and sulfur is less than 20 min per sample. Calibration is carried out using a standard additions method with mixed standards. The method is accurate and precise, and appears to be adequate for routine analyses.
Headspace Gas Chromatographic Estimation of Some Yogurt Volatiles
Authors: Ulberth Franz
Published: February 2020

A headspace gas chromatographic method Is described for the determination of acetaldehyde, ethanol, acetone, dlacetyl, and 2-butanone In yogurt. Yogurt (2 g) is equilibrated 1 h in a 10 mL vial at 60 °C, and 0.25 mL headspace gas Is splitinjected. The volatiles are baseline-separated In less than 5 min by using a thick film capillary column coated with SE-54. An external standard calibration method fulfills the requirements for an accurate determination of the yogurt aroma components. The accuracy of this method was checked by the standard addition method. The precision of the method, In terms of the relative standard deviation, depends on the analyte concentration. At the 10 ppm volatile level, RSD Is 2%, and at the 0.1 ppm level, 15%.
Dry Rehydratable Film for Enumeration of Total Coliforms and Escherichia coli in Foods: Collaborative Study
Authors: Curiale Michael S , Sons Therese , Mclver Dawn , McAllister J Sue , Halsey Barbara , Roblee Diane , Fox Terrance L
Published: February 2020

Rehydratable dry-film plating methods for total coliforms and Escherichia coll In foods have been compared to the AOAC most probable number methods. Fourteen laboratories participated In the collaborative study. Three coliform and £. coll levels In 6 samples of 4 product types (flour, nuts, cheese, and beef with gravy) and in 3 samples of 2 product types (mushrooms and raw turkey) were tested In duplicate by the participants. The mean log counts for the 3 methods were comparable. In general, the repeatability and reproducibility variances of the plating methods were as good as or better than that of the MPN method. The method has been adopted official first action by AOAC.
Liquid Chromatographic Determination of Fluometuron and Metabolites in Soil
Authors: Mueller Thomas C , Moorman Thomas B
Published: February 2020

A rapid, sensitive method Is described for the determination of fluometuron and Its soil metabolites In 4 soil types. The method consists of extraction of moist soil samples with methanol, filtration, liquid chromatographic separation of methanol-soluble components using a C18 column, and fluorescence detection with excitation at 292 nm and emission measured at 345 nm. Fluometuron recoveries from fortified soils were >90% from the Dundee, Okalona, Cecil, and Ships soils. Recoveries from a Dundee silt loam for desmethyl fluometuron, 3-(trlfluoromethyl)phenyl urea, and 3- (trifluoromethyl)anillne were 77, 77, and 35%, respectively. Average percent relative standard deviations of Dundee soil extracts were 5.3% for fluometuron and <8.0% for each metabolite. The limit of detection for fluometuron and each of its soil metabolites was 25 ng/g soil.
Staphylococcus aureus
Authors: Bergdoll Merlin S
Published: February 2020

The analytical methods for the detection of the staphylococcal enterotoxins can be divided into 2 categories: (1) methods for detection of enterotoxin-producing staphylococcal strains; (2) methods for detection of enterotoxin in foods. Gel diffusion methods (Ouchterlony, microslide), in which the enterotoxin produced by any given strain is compared to one of the identified enterotoxins, are used most frequently for strain testing. The sensitivity of these methods is from 0.1 to 0.5 μg enterotoxin/mL, which is normally adequate to determine the enterotoxigenicity of strains. The methods for the detection of enterotoxin in foods need to be much more sensitive to detect less than 1 ng of enterotoxin/g of food that may be present. The radioimmunoassay (RIA), the enzymelinked immunosorbent assay (ELISA), and the reversed passive latex agglutination (RPLA) method have the necessary sensitivity to detect 1 ng/g of enterotoxin in foods without the use of complicated extraction-concentration procedures. Kits based on the ELISA and RPLA methods are now available commercially for the detection of enterotoxins in foods. Tests have shown that the ELISA methods are somewhat more sensitive than the RPLA method.
Liquid Chromatographic Determination of Chlortetracycline Hydrochloride in Ruminant and Poultry/Swine Feeds
Authors: Holland David C , Faul Kent C , Roybal Jose E , Munns Robert K , Shimoda Wilbert
Published: February 2020

A liquid chromatographic (LC) method is described for the determination of chlortetracycline hydrochloride (CTC) in poultry/swine and ruminant feeds in the 10-100 ppm range and in premix. CTC is extracted from ground feed/premix with acidified acetone, and the extract is filtered through a Millex-HV filter or disposable C 18 column. The filtrate Is partitioned with methylene chloride when additional cleanup is necessary. A Nova-Pak C 18 column Is used for LC separation with determination at 370 nm. The average recovery of CTC from premix was 95% with a standard deviation (SD) of 1.70 and a coefficient of variation (CV) of 1.79%. The overall average recovery from feeds was 77% with an SO of 3.18 and a CV of 4.10%.
Competitive Direct Enzyme-Linked Immunosorbent Screening Assay for the Detection of Sulfamethazine Contamination of Animal Feeds
Authors: Holland Deborah Dixon E , Katz Stanley E
Published: February 2020

A sensitive screening method has been developed for detecting sulfamethazine (SMZ) contamination of feeds by using either polyclonal or monoclonal antibodies and a direct competitive enzyme-linked immunosorbent screening assay (ELISA). Feed samples of 25.0 g are extracted with 0.5N HCI and centrifuged. The extract is adjusted to pH 7.0 with 3.0N NaOH and recentrifuged. This pH-adjusted extract is used in the EUSA. Levels as low as 0.004 μg SMZ/g feed were detected In supplemented extracts by polyclonal antibodies; levels of 0.4 μg SMZ/g feed were detected by a monoclonal antibody.
Reducing Solvent Consumption in Automated Gel Permeation Chromatographic Cleanup for Pesticide Residue Analysis: A Modified GPC AutoPrep 1002
Authors: Patterson John R
Published: February 2020

Modifications to the gel permeation chromatographic apparatus recommended in AOAC method 984.21 for multiresidue analysis of organochlorine pesticides in animal fat are described. By using 1.0 mL sample loops and a 1.0 cm id column, organic solvent usage was reduced by 85%. Organochlorine pesticides were collected in a 14 mL fraction. Mean recoveries using the modified apparatus for aldrin, α-BHC, lindane, dieldrin, p,p′-DDD, p,p′-DDE, p,p′-DDT, heptachlor, heptachlor epoxide, methoxychlor, and mirex from beef fat fortified at 0.10-2.75 μg/g were in the 91.4-108% range, with CV of 3.3-10.0%.
Liquid Chromatographic Determination of Paraquat and Diquat in Crops Using a Silica Column with Aqueous Ionic Mobile Phase
Authors: Chichila Tina M , Walters Stephen M
Published: February 2020

A method was developed for the determination of paraquat (PQ) and diquat (DQ) in high moisture food crops. Samples were digested with 6M HCI, and the herbicides were isolated from the digest using pH-controlled silica solid phase extraction. The analyte8 were then determined by ion-pairing liquid chromatography with a silica analytical column, sodium chloride as the ion-pairing reagent, and acetonitrile as the organic modifier. A diode array UV absorbance detector was used to simultaneously quantify PQ and DQ at their respective maximum absorbance wavelengths, 257 and 310 nm. Average recoveries of PQ and DQ standards from 4 different crops fortified at 0.01-0.50 ppm levels ranged from 79.3 to 104.8%.
Quantitative Analysis of Agricultural and Food Products: A New Instrumental and Computerized Approach
Authors: Lanher Bertrand S
Published: February 2020

A new software package, ANAQUANT, was specifically designed for a long-term approach to the quantitation of compounds In biological products. Its functionality and validity were tested by measuring fat and protein contents In liquid cow's milk using Fourier transform Infrared spectrometry and a handcrafted transmission flow cell. Calibration and validation standard deviations were 0.2484 and 0.3987 g/kg, respectively, for the prediction of proteins, and 0.3163 and 0.4222 g/L, respectively, for the prediction of butterfat. One month elapsed between calibration of the Instrument and the validation study. Results are consistent with those proposed in the literature.
Determination of Dicloxacillin Preparations by Liquid Chromatography
Authors: Hsu Mei-Chich , Fann Yann-Jen
Published: February 2020

A reversed-phase liquid chromatographic method was developed for the assay of dicloxacillin In bulk drugs and pharmaceutical preparations. The samples were analyzed on a μBondapak (C18) column with a mobile phase of methanol-4% acetic acid (60 + 40) at a flow rate of 1.5 mL/mln, with UV absorbance detection at 254 nm. An equation was derived showing a linear relationship between peak area ratios of dicloxacillin to dimethylphthalate (internal standard) and the dicloxacillin concentration over a range of 2-30 μg (r = 0.9999). Standard addition recoveries ranged from 98.65 to 100.74% (mean 99.70%, n = 6). The coefficient of variation was less than 0.24%. The assay results were compared with those obtained by the official microbiological method, which indicated that the proposed method Is a suitable substitute for the microbiological method for potency assays and stability studies of dicloxacillin preparations.
Column Extraction of Residues of Several Pesticides from Fruits and Vegetables: A Simple Multiresidue Analysis Method
Authors: Kadenczki Lajos , Arpad Zoltan , Gardi Ivan , Ambrus Arpad , Gyorfi Laszlo , Reese Gabriela , Ebing Winfried
Published: February 2020

Homogeneous sample pulp, prepared from fruits and vegetables of different water content with or without additional water, Is adsorbed on the surface of activated Florisll to obtain a free-flowing powder, which is extracted In a glass column with ethyl acetate or methylene chloride-acetone (9 + 1, v/v). In most cases, no further cleanup Is necessary for subsequent gas chromatographic measurement. The recovery of pesticide residues, Including carbamate, organochlorlne, organophosphate, synthetic pyrethrold, triazlne, urea, and miscellaneous pesticides, Is generally ≥80%, and Is Independent of the sample material. The column extraction Is faster, less laborious, and less expensive than extractions based on traditional techniques, liquid partition, or other conventional chromatographic procedures.
Composition of Pineapple Juice
Authors: Krueger Dana A , Krueger Rae-Gabrielle , Maciel Jeanne
Published: February 2020

Major and some minor constituents were determined for a series of fresh pineapple juices. Results Include: soluble solids 11.2-16.2 g/100 g, acidity (reported as citric acid) 0.46-1.21 g citric acid/100 mL, fructose 1.72-4.75 g/100 mL, glucose 1.21-4.52 g/100 mL, sucrose 2.47-9.73 g/100 mL, citric acid 0.439-1.151 g/100 mL, malic acid 0.073- 0.391, Isocltrlc acid 80-265 mg/L, potassium 830- 1410 mg/L, formol value 0.74-1.69 meq/100 mL, proline 11-44 mg/L, and carbon isotope ratio 13.5- 11.2%o PDB. Use of these compositional values In the detection of adulterated pineapple juice is discussed.
Determination of Insoluble and Soluble Dietary Fiber in Foods and Food Products: Collaborative Study
Authors: Prosky Leon , Asp Nils-Georg , Schweizer Thomas F , Devries Jonathan W , Furda Ivan
Published: February 2020

A collaborative study was conducted to validate a method to determine the Insoluble dietary fiber (IDF) and soluble dietary fiber (SDF) contents of foods and food products by using a combination of enzymatic and gravimetric procedures. The method was basically the same as that for determining total dietary fiber, which was adopted as final action by AOAC and further modified to Include changes in the concentration of buffer and base and substitution of hydrochloric acid for phosphoric acid. Thirty-nine collaborators were each sent 7 test samples In a staggered design for duplicate blind analysis. They were also sent a standard containing 4.3-5.4% IDF and 1.5-2.7% SDF. The 22 foods that were analyzed for IDF and SDF were cabbage, carrots, French beans, kidney beans, butter beans, okra, onions, parsley, chick peas, brussels sprouts, barley, rye flour, turnips, soy bran, wheat germ, raisins, Callmyrna figs, prune powder, Black Mission figs, apple powder, peach powder, and apricot powder. Both IDF and SDF values were calculated as the weight of residue minus the weight of protein and ash reported on a dry weight basis. The reproducibility relative standard deviation (RSDR) of the IDF results ranged from 3.68 to 19.44% for the foods analyzed; almost half the test samples had an RSDR <10%. The RSDR values for the SDF results were somewhat higher. Approximately 50% of the foods analyzed had an RSDR >20%, and 45% had an RSDR between 10 and 20%. An RSDR approaching 45% was calculated for the 2 test samples with the lowest SDF content, 1.35 and 1.90%. Raisins and prune powder had high RSDR values for both SDF and IDF. A major reason for high RSDR values seems to be filtration problems, which are avoidable by analyzing 0.5-0.25 g test samples. The method for the determination of SDF requires further study, but the method for the determination of IDF was adopted first action by AOAC International.
History of the IUPAC/ISO/AOAC Harmonization Program
Authors: Horwitz William
Published: February 2020

As a result of the preference of the Joint Food and Agriculture Organization/World Health Organization Codex Alimentarius Program to endorse methods of analysis for which interlaboratory performance parameters are available, many international organizations now conduct method-performance (collaborative) studies. International meetings sponsored by the International Union of Pure and Applied Chemistry, the International Organization for Standardization, and AOAC International have produced a harmonized protocol for the design, conduct, and interpretation of method-performance studies, and this protocol Is being Implemented by many method standardization organizations. The same group of organizations hopes to provide a harmonized protocol for the quality control and quality assurance of laboratory (analyst) performance.
Liquid Chromatographic Determination of Gentian Violet in Poultry Feed
Authors: Roybal José E , Munns Robert K , Holland David C , Burkepile Roger G , Hurlbut Jeffrey A
Published: February 2020

A liquid chromatographic (LC) method Is presented for the determination of gentian violet (GV) In poultry feed (turkey/chicken) at the therapeutic feeding level of 4-8 ppm. GV Is extracted from feed with acidified methanol, an aliquot of the supernatant is diluted with mobile phase, and the solution is filtered. LC analysis Is performed by Isocratlc elutlon with a buffered mobile phase on an Adtech CN (cyano) column with amperometrlc electrochemical detection (ED) at +1.000 V or detection in the visible absorbance mode at 588 nm. The overall average recovery of GV from chicken feed spiked at 2.5,5, and 10 ppm was 103% (standard deviation = 6.6; coefficient of variation = 6.4%) by LC/ED analysis. Data for recovery of GV from chicken and turkey feeds, fortified with 1% GV premlx at feeding levels of 4 and 8 ppm, are presented and discussed. Data for the 2 detection techniques are compared.
Bioassay, Extraction, and Purification Procedures for Wortmannin, the Hemorrhagic Factor Produced by Fusarium oxysporum N17B Grown on Rice
Authors: Abbas Hamed K , Mirocha Chester J , Shier W Thomas , Gunther Roland
Published: February 2020

Rats and cultured cells were treated with purified wortmannin toxin, crude fungal extracts, and partially purified preparations for periods of 5-96 h. A single dose of the toxic fractions containing the equivalent of 2.5 g fungus-infested rice resulted in death, hematuria, and hemorrhage in the urinary bladder, Intestine, stomach, heart, and thymus of rats. Purified wortmannin produced the same effects at 4 mg/kg. Fractions that were toxic in vivo also had cytotoxic properties with various cultured cell lines at concentrations ranging from 1.2 to >50 mg equivalents of fungus-infested rice extracted/mL Purified wortmannin was cytotoxic at 50 μg/mL.
Multiresidue Method for Quantitation of Organophosphorus Pesticides in Vegetable and Animal Foods
Authors: Leoni Valerio , Caricchia Anna M , Chiavarini Salvatore
Published: February 2020

A critical review of multiresidue analytical methods was performed to develop an easy procedure that can be applied with slight modifications to vegetable and animal food samples. The multiresidue method described Is applicable to the quantitative determination of 28 organophosphorus pesticides In fatty as well as nonfatty foods. The foods are divided Into 4 groups according to extraction process (acetone and acetone-water for samples with moisture content <45%) and cleanup (on active carbon- Cellte, on disposable mlnicolumns of Kieselguhr- type material, and on disposable mlnicolumns of bonded-phase silica, according to fat and pigment content). A further fractionation on silica-gel microcolumns can be Included In the procedure. A wide-bore column (SPB-5) with flame photometric detection operated in phosphorus mode (FPD-P) was chosen for gas chromatographic determination. Recoveries from apples, olive oil, whole milk, pasta, and eggs are reported. Two packed columns (4% OV-101 and SP2250- SP2401) with FPD-P were tested as confirmation columns. The method is suitable for a total diet study.
Detection of Beef, Sheep, Deer, and Horse Meat in Cooked Meat Products by Enzyme-Linked Immunosorbent Assay
Authors: Andrews Connie D , Berger Ronald G , Mageau Richard P , Schwab Bernard , Johnston Ralph W
Published: February 2020

Enzyme-linked Immunosorbent assays (ELISAs) are described for the detection of mutton, beef, horse meat, and venison In cooked meat products. They represent an expansion of the species detection capabilities of previously described ELISAs for the detection of pork and poultry In cooked foods. These double antibody sandwich ELISAs recognize heat-resistant antigens in simple aqueous extracts of cooked meat products. Tests on laboratory-prepared and commercially cooked meat products accurately differentiated all tested meat components. However, some canned baby food meats and one canned meat product did not react in any of these ELISAs. Sensitivity of the assays was 0.13% or greater in tests of diluted cooked extract mixtures. No product Ingredients were found that interfered with test performance.
Direct Determination of Individual Organic Fluorine Compounds by Aluminum Monofluoride Molecular Absorption Spectrometry
Authors: Venkateswarlu Pothapragada , Blackwell John A , Jewell Kelly , Kirsch Gary W
Published: February 2020

Recovery of organic fluorine by direct aluminum monofluoride molecular absorption spectrophotometry, following injection of samples into the graphite furnace and use of sodium fluoride standards, varies from 0 to 100% from compound to compound depending on the compound's volatility and the mechanism of thermal decomposition. This problem has now been overcome by employing standards made from the very same fluorochemical that is present in the sample. This approach is applicable to samples containing only 1 known fluorochemical. Some industrial applications of this technique that meet the needs of quality control, industrial hygiene policies, and certain U.S. Food and Drug Administration regulations are described.
Analysis of Fatty and Nonfat Foods for Chlorophenoxy Alkyl Acids and Pentachlorophenol
Authors: Hopper, Marvin L , Mcmahon Bernadette , Griffitt Kenneth R , Cline Kevin , Mary Ellen Fleming-Jones , Kendall Donald C
Published: February 2020

A multiresidue method has been developed to analyze low-level residues of chlorophenoxy alkyl acids and pentachlorophenol (PCP) in fatty and nonfat foods. The acidified sample is extracted, cleaned up using gel permeation chromatography, methylated by ion-pair alkylation with tetrabutylammonium hydroxide and methyl iodide, cleaned up using Florisil, and determined by gas chromatography using electron capture and/or electrolytic conductivity detectors. Recoveries ranged from 53 to 75% for 2,4-D at 200 ppb, 61 to 93% for 2,4,5-T at 80 ppb, and 76 to 84% for PCP at 20 ppb fortified in a variety of food items. Also, 31 other herbicides were evaluated through this procedure.
Liquid Chromatographic Screening Method for Fluorescent Derivatives of Chlorophenoxy Acid Herbicides in Water
Authors: Suzuki Toshinari , Watanabe Satoru
Published: February 2020

A liquid chromatographic method for screening 9 chlorophenoxy acids (2,4-D; 2,4-DP; 2,4-DB; MCPA; MCPP; MCPB; 2,4,5-T; 2,4,5-TP; and 2,4,5-TB) and their ethyl esters in ground- and tap water is presented. The water samples are acidified and subjected to either liquid-liquid or solid-phase extraction. The extracts obtained are saponified in 0.03N NaOH-50% methanol (1+1) and the acidic compounds are re-extracted with ethyl acetate-n-hexane (8 + 2) after acidification and derivatized with 9- anthryldiazomethane. Derivatized compounds are analyzed using reversed-phase column chromatography with fluorescence detection (excitation, 365 nm; emission, 412 nm). Recoveries of analytes from 20 mL water samples were greater than 90%, and the average coefficient of variation was within 5.0% at 0.5 ppb for both extraction methods. These methods are simple and useful for the determination of small amounts of chlorophenoxy herbicides. Solid-phase extraction is suitable for screening a large number of samples simultaneously, and liquid extraction for separate determination of the acids and ethyl esters of the herbicides was improved by introducing a saponification step.
Determination Of Tryptophan Content In Infant Formulas And
Medical Nutritionals
Authors: Garcia Saul E , Baxter Jeffrey H
Published: February 2020

A method was developed for determination of total tryptophan content in soy- and milk-based nutritional products. The method uses enzymatic (pronase) digestion of the protein to release tryptophan, which is separated and quantitated by isocratic reversed-phase liquid chromatography with fluorescence detection. Enzymatic digestion is completed for products containing these types of proteins in less than 6 h and is accomplished under chemically mild conditions (pH 8.5,50°C), which do not significantly degrade tryptophan. Chromatographic separation is complete in about 8 min, including an internal standard. The precision of the method is 1-2% relative standard deviation. Accuracy is demonstrated by agreement with theoretical values for standard proteins (amino acid sequence known) and by quantitative recoveries of overspikes, which use either free tryptophan or a standard protein as the spiking material. The method allows determinations on samples containing a wide range of tryptophan values. Appropriate sample size selection and verification of digestion time requirements should allow the method to be applied to different protein types as well. The method allows 24 h turnaround of tryptophan analyses, and quantitative recoveries represent a significant improvement on existing techniques applied to infant formulas and other nutritional products.
Survey of Bottled Drinking Water Sold in Canada. Part 1.
Lead, Cadmium, Arsenic, Aluminum, and Fluoride
Authors: Dabeka Robert W , Conacher Henry B S , Salminen John , Nixon Gerald R , Riedel Gunther , Crocker Ron , DubÉ Gilles
Published: February 2020

Samples of bottled water (n = 172) offered for sale in Canada were analyzed for lead, cadmium, arsenic, aluminum, and fluoride: means and ranges (μg/g) found were, respectively, 0.0026 (<0.0010- 0.074), 0.00018 (<0.0001-0.0004), 0.0030 (<0.001- 0.048), 0.027 (<0.010-0.568), and 0.543 (<0.050- 5.85). Comparison of levels among mineral waters (n = 64), spring waters (n = 77), and miscellaneous waters (n = 31) indicated appreciable differences only in the case of fluoride. For fluoride, the means and medians (μg/g) for mineral, spring, and miscellaneous waters were 1.179 and 0.455, 0.152 and 0.090, and 0.201 and <0.050, respectively. No samples were found in violation of the tolerances in the Canadian Food and Drug Regulations; however, 1 sample (in a lead-soldered can) contained lead and 15 samples contained fluoride at levels above the limits recommended by the Guidelines for Canadian Drinking Water (tap-water) Quality.
Spectrophotometric Method for Determination of Cephalexin
in Its Dosage Forms
Authors: Patel Ila T , Devani Muljibhai B , Patel Tushar M
Published: February 2020

A simple, rapid, and specific method was developed for determination of cephalexin and its dosage forms. The method is based on the reaction of cephalexin with acetylacetone-formaldehyde reagent to give a yellow chromophore measurable at 400 nm. The color is stable for 3 h. Beer's law is valid within a concentration range of 10-100 μg/mL for cephalexin. All variables were studied to optimize the reaction conditions. The method is specific for amino β-lactam antibiotics. Non-amino β-lactam antibiotics do not interfere. No interference was observed in the presence of common pharmaceutical adjuvants. The validity of the method was tested by analyzing cephalexin tablets, capsules, and oral suspension. Good recoveries were obtained for these preparations. The results were comparable with those obtained by the official procedure
Survey of Arsenic in Total Diet Food Composites and Estimation of the Dietary Intake of Arsenic by Canadian Adults and Children
Authors: Dabeka Robert W , McKenzie Arthur D , Lacroix Gladys M A , Bowe Chantal Cleroux Susan , Graham Russell A , Conacher Henry B S , Verdeer Pam
Published: February 2020

During a comprehensive total diet study extending from 1985 to 1988, foods were collected in 6 Canadian cities (in one of them, a pilot study was conducted twice). For each of the 7 collections, foods were processed into 112 composites (105 in the initial pilot trial). Total arsenic was determined in all samples. The mean, median, and range of arsenic concentrations in all samples were 73.2,5.1, and <0.1-4830 ng/g, respectively. Food groups containing the highest mean arsenic levels were fish (1662 ng/g), meat and poultry (24.3 ng/g), bakery goods and cereals (24.5 ng/g), and fats and oils (19.0 ng/g). The estimated daily dietary ingestion of total arsenic by the average Canadian was 38.1 μg and varied from 14.9 μg for the 1- to 4-year-old group to 59.2 μg for 20- to 39-year-old males.
Aflatoxin Contamination in Foods and Foodstuffs in Tokyo: 1986-1990
Authors: Tabata Setsuko , Kamimura Hisashi , Ibe Akihiro , Hashimoto Hideki , Iida Mami , Tamura Yukihiro , Nishima Taichtro
Published: February 2020

Aflatoxins were determined in 3054 samples of foods or foodstuffs, including cereals, nuts, beans, spices, dairy products, dry fruits, and edible oil. Samples were collected in Tokyo from 1986 to 1990. Aflatoxins were found in rice products, adlay, corn, crude sugar, peanut products, pistachio nuts, brazil nuts, sesame products, butter beans, white pepper, red pepper, paprika, nutmeg, and mixed spices. The highest incidence of aflatoxin contamination was observed in nutmeg (80%), and the highest level of aflatoxin B1 was observed in pistachio nuts (1382 ppb).
Comparison of Liquid Chromatographic Method to AOAC Microbiological Method for Determination of L-Tryptophan in Tablets and Capsules
Authors: Kim Henry S , Angyal Gerald
Published: February 2020

A reversed-phase liquid chromatographic (LC) method coupled with precolumn derivatization of L-tryptophan with phenylisothiocyanate was compared to the AOAC microbiological method for determining L-tryptophan in tablets and capsules. For the microbiological method, the concentrations of L-tryptophan were 4-8% lower in autoclaved test samples (hot method) than in test samples that were not autoclaved (cold method). When L-tryptophan values obtained by the LC method were compared to those obtained by the cold microbiological method, no significant differences were observed (P > 0.05). The mean relative standard deviations were 2.9% for the LC method and 1.6% for the cold microbiological method. The mean recoveries of standard L-tryptophan added before analysis were 99% for the LC method and 101 % for the cold microbiological method. These results demonstrate that both methods are reliable for determining free L-tryptophan contained in tablets and capsules. However, the LC method has the advantages of using a smaller test portion and having a shorter analysis time.
Calculation of Juice Content in a Diluted Fruit Juice Beverage
Authors: Lindsay Chester W
Published: February 2020

A1990 amendment to the Food, Drug and Cosmetic Act states that if a food purports to be a beverage containing vegetable or fruit juice, it shall be deemed to be misbranded unless its label bears a statement of the total percentage of such fruit or vegetable juice content. The intent of the present paper is to assist beverage manufacturers in calculating the juice content of their products for the purpose of a label declaration.
Small-Scale Survey of Organotin Compounds in Household Commodities
Authors: Yamada Sadaji , Fujii Yuko , Mikami Eiichi , Kawamura Norihisa , Hayakawa Junko , Aoki Kazuharu , Fukaya Megumu , Terao Chikahiro
Published: February 2020

Ninety-five commercially available items were analyzed for a small-scale survey of organotin compounds (OTCs) in household commodities such as textile products, shoe polish, adhesives, paint, and wax. Neither tributyltin nor triphenyltin species were found in any items; however, di- and trioctyltin and/or dibutyltin species (DOT, TOT, and DBT, respectively) were detected in 15 items; DOT was found in 14 items, TOT in 5 items, and DBT in 4 items. DOT was found in 2 diaper covers at about 0.1 %. Detection frequencies of OTC were 6/10 for diaper covers, 3/10 for bibs, 2/10 for sanitary panties, 1/5 for outergarments, 1/5 for stockings, 1/5 for socks, and 1/10 for shoe polish.
Extraction and Gas Chromatographic Screening of 14 Chlorinated Pesticides in Crayfish (Procambarus clarkii) Hepatopancreas
Authors: Lott Heidi M , Barker Steven A
Published: February 2020

A multiresidue isolation technique using matrix solid-phase dispersion (MSPD) and gas chromatography/ electron capture detection is applied to crayfish (Procambarus clarkii) hepatopancreas for the extraction and determination of 14 chlorinated pesticides (α-BHC, β-BHC, lindane, heptachlor, aldrin, heptachlorepoxide, p,p'-DDE, dieldrin, endrin, 4,4'- DDD, endrin aldehyde, p,p'-DDT, endosulfan sulfate, and methoxychlor). Pureed crayfish hepatopancreata (0.5 g aliquot) are fortified with the 14 pesticides and with δ-BHC as an internal standard before blending with 2 g C18 (octadecylsilyl)- derivatized silica. The C18-hepatopancreas matrix blend and 2 g activated Florisil comprise an extraction column from which the pesticides are eluted by adding 8 mL acetonitrile. Two microliters of the eluate is directly analyzed by gas chromatography with electron capture detection. Unfortified blank controls are treated similarly. The eluate contained all the pesticide analytes and was free of interfering coextractants at most fortification levels. Correlation coefficients for the 14 extracted pesticide standard curves (linear regression analysis) ranged from 0.9685 to 0.9985. Average relative percent recoveries (recoveries for all pesticides ranged from 55 ± 10.4% to 118 ± 45.2%, n = 15 for each pesticide) over the range of concentrations examined, interassay variability (7.1 ± 5.7% to 16.0 ± 5.6%, n = 15 for each pesticide), and intra-assay variability (0.0-26.2%, n = 5 for each pesticide) indicated that the MSPD methodology allowed for the successful extraction and determination of the 14 chlorinated pesticides at 125-2000 ng/g levels in crayfish hepatopancreas.
Total Organochlorine Content of Fish from the Great Lakes
Authors: Newsome W Harvey , Andrews Paul , Conacher Henry B S , Rao R R , Chatt A
Published: February 2020

Residues of polychlorinated biphenyls (PCBs) and organochlorine pesticides were determined in several species of commercial fish from the Great Lakes and compared to the total organic chlorine determined by neutron activation analysis. The mean organochlorine contents ranged from 44 to 138 ppm (lipid basis) and were 5 to 72 times higher than the contents of PCBs and organochlorine pesticides. Marine fish also contained a large proportion of unidentified organic chlorine. The unknown material in the Great Lakes fish was found to chromatograph with the high molecular weight lipid fraction by gel permeation chromatography.
Fast Atom Bombardment Mass Spectrometric Analysis of Base Hydrolyzed γ-Lactone
Authors: Baker Randall J
Published: February 2020

Fast atom bombardment (FAB) mass spectrometry (MS) is used to characterize the γ-hydroxy carboxylic acid (γ-HCa) formed from base hydrolyzed γ-lactone at room temperature. Acidification of this base hydrolyzed solution reconverts the γ-HCa back to γ-lactone. Mass shift differences between tetramethylammonium (TMA+) and Na+ ion-pairs with the anionic γ-HCarboxylate(–) (γ-HC(–)) are used to confirm molecular ion identifications. FAB ionization was required to provide mass characterization of the γ-HCa. Electron ionization (El) MS of the γ-HCa was unsuccessful and reconverted γ-HCa back to γ-lactone because of complete thermally induced dehydration. The present paper suggests structures for El fragmentation that support the molecular structure of γ-lactone.