bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of 2,3?7,8-Tetrachlorodibenzo-p-Dioxin in Fish, Using Electron Capture Gas Chromatography with Confirmation by Mass Spectrometry: Interlaboratory Study
Authors: Fehringer Norbert V , Walters Stephen M , Niemann Richard A 
Published: February 2020

Abstract
An interlaboratory study of the determination of 2,3,7,8-tetrachlorodibenzo- p-dioxin (2,3,7,8-TCDD) in fish was conducted by 6 analysts in 4 laboratories using high resolution gas chromatography with electron capture detection (HRGC-EC) for quantitative screening analysis. Samples consisted of 3 Great Lakes channel catfish homogenates containing different levels of bioincurred 2,3,7,8-TCDD; 1 of these was prepared in duplicate and another was prepared both with and without standard 2,3,7,8-TCDD fortification for a total of 5 samples per set. All methods used included addition of 1,3,7,8-TCDD surrogate (to correct for procedural losses) followed by ethanolic KOH digestion and hexane extraction. Certain cleanup steps used, including sulfuric acid washing and multidimensional column liquid chromatographic procedures, varied among laboratories. Mean HRGC-EC results for the bioincurred residues were 56.6, 25.2, and 7.7 pg/g (ppt) with corresponding relative standard deviations (RSDs) of 9.1,18.6, and 53.2%. Average determination of standard 2,3,7,8- TCDD from the fortified sample (corrected for surrogate recoveries averaging 74.6%) was 106% of the added amount (30.9 pg/g) with 11.0% RSD. HRGC-multiple ion detection mass spectrometry (MS), monitoring 12 ions, was used for confirmation. With the exception of several results from 1 analyst, HRGC-MS and HRGC-EC quantitations were in good agreement. All but 1 result reported met all of the MS ide ntity criteria.
Sampling in the Analytical Scheme
Authors: Garfield Frederick M 
Published: February 2020

Abstract
The general principles of sampling in the analytical scheme, sampling definitions, and sampling planning are considered. Statistical considerations are stressed with attention to sampling by attributes and variables and the use of sampling control charts. Sampling techniques, records and chain-of-custody procedures, sample handling, laboratory sampling, and sample preparation for analysis, as well as reasons and causes of sampling errors, are discussed.
Simple, Rapid, and Portable Chromatographic Tetrazolium Reduction Method for Detection of Potassium Cyanide in Medicinal Drugs and Confectionery
Authors: Bhagyalakshmi Kamasala , Kumar Nanguneri V Nanda 
Published: February 2020

Abstract
A simple, rapid, and portable paper chromatographic method for detection of potassium cyanide in medicinal drugs and a few confectionery samples is described. Potassium cyanide is extracted in methanol and concentrated. Acetone-water-1.5% EDTA (4 + 5.5 + 0.5) mixture is used as the solvent system for paper chromatography. The KCN chromatograms appear as pink spots on paper due to reduction of the chromogenic salt 2-(4-iodophenyl)-3-(4-nitrophenyl)-5- phenyl tetrazolium chloride; phenazonium methosulfate is a catalyst. Microgram amounts of KCN can be separated and detected in the laboratory or the marketplace because of the simplicity of the method.
Liquid Chromatographic Determination of Miconazole Nitrate in Creams and Suppositories
Authors: Tyler Theodore A , Genzale Judith A 
Published: February 2020

Abstract
A rapid method has been developed for the determination of miconazole nitrate in creams and suppositories. The sample is dissolved in ethanol, diluted in acetonitrile-water (1 + 1), and injected onto a C18 column. The mobile phase consists of 55% acetonitrile, a triethylammonium phosphate buffer, and an ion-pairing agent. The total run time is less than 4 min, and the active ingredient is determined using absorbance detection at 214 nm. The mean recovery of miconazole from spiked placebo samples was 99.7 ± 0.7% for the cream samples at the 2% level and 98.8 ± 0.3% for the suppository samples at the 4% level.
Improved Turbidimetric Assay of Tylosin in Premix and Animal Feeds Not Containing Urea
Authors: Coleman Mark R 
Published: February 2020

Abstract
A turbidimetric method is described for the determination of tylosin in premix and animal feeds not containing urea. This method includes several modifications of existing tylosin turbidimetric and AOAC plate assays to remove interferences from the feed, to concentrate low levels of tylosin, and to reduce the variability of the assay results. An acidic alumina column cleanup step has been incorporated into the method to remove interferences from feed ingredients. A disposable C18 column was used to concentrate the tylosin from low-level feeds, and the use of a larger analytical sample size has decreased the variability of the assay results. Average recoveries of tylosin added to chicken and swine rations were 98 and 101%, respectively.
Determination of Iodine Value by Bromine/Instrumental Neutron Activation Analysis
Authors: Iskander Felib Y 
Published: February 2020

Abstract
A new microanalytical method has been developed to measure iodine value (IV) of oils and fats. Bromine vapor was used to saturate the ethylenic double bonds, and reacted bromine was determined by instrumental neutron activation analysis. The method was applied to measure the iodine values of 7 commercially available vegetable oils: almond oil, sunflower oil, peanut oil, soy oil, sesame oil, corn oil, and olive oil. No significant difference was observed between the iodine value determined by the proposed method and that determined by an officially approved (Hübl) method. Bromine measurements can be performed up to 150 days after bromination with no significant variation in iodine value; thus, availability of an irradiation facility on the premises is not a limitation. No corrosive and toxic reagents are required, and the method is faster than the official methods. The method is also applicable to measuring iodine values of free or esterified fatty acids.
Determination of Fluoroacetate in Biological Matrixes as the Dodecyl Ester
Authors: Burke Daniel G , Lew Dennis K T , Cominos Xenophon 
Published: February 2020

Abstract
A new method for the quantitative determination of fluoroacetate in biological samples was applied to a number of avian samples. Fluoroacetate is isolated as its potassium salt by ion-exchange chromatography and directly converted to its dodecyl ester, using a novel derivatization procedure. The ester is quantified by capillary gas chromatography with a flame ionization detector for the range 1.0-10.0 μg/ g and by selected ion monitoring GC/mass spectrometry for the range 0.01-1.00 μg/g. Recoveries from 1 g chicken muscle were about 80%. The method was applied to the determination of fluoroacetate in the crop, stomach, liver, heart, intestine, and breast muscle of 5 Zebra finches (Peophila guttata) that had been fed millet containing 9 μg/g of sodium fluoroacetate. Despite a wide variation in dose, the levels in organs and tissues were approximately 1 μg/g except for heart tissue which was about 2 μg/g. The presence of interfering peaks at low levels necessitated the use of selected ion monitoring GC/MS when sample weights were less than 1 g or when levels were less than 1 μg/ g. Samples can be analyzed within hours of receipt; therefore, the method is suitable for routine use in a diagnostic laboratory.
Rapid Gas Chromatographic Method Using Nitrogen-Phosphorus Detection for N-Nitrosodimethylamine in 2,4-D and MCPA Herbicide Formulations
Authors: Scharfe Ronald R , Mclenaghan Charles C 
Published: February 2020

Abstract
A simple and rapid analytical method has been developed for the determination of JV-nitrosodimethylamine (NDMA) in amine salts of phenoxy herbicide formulations of 2,4-D and MCPA, plus mixtures of these with mecoprop and dicamba amine salts. Sample preparation consists of direct extraction using pre-packed disposable extraction tubes eluted with dichloromethane followed by cleanup on a disposable silica gel mini-column using ethyl acetate as eluting solvent. Samples are injected on-column for gas chromatography with a Megabore fused silica column; the NDMA is measured by a thermionic specific detector (TSD) that is selective for nitrogen-phosphorus (NP). A detection limit of 0.1 μg/mL was easily attainable without any concentration step because the solvent volume is minimal. TSD and thermal energy analyzer (TEA) results have been compared and confirmed by gas chromatography/mass spectrometry. Recovery studies were performed as well as a reproducibility study on one of the 2,4-D formulations.
Effect of Commercial Processing on Pesticide Residues in Selected Fruits and Vegetables
Authors: Elkins Edgar R 
Published: February 2020

Abstract
Commercial food processing operations such as washing, blanching, and cooking remove major portions of the pesticide residues that are currently permitted on the raw agricultural crop. These unit operations are reviewed for selected products, along with degree of residue removal at each step. For example, washing plus peeling removes 99% of carbaryl and malathion residues from tomatoes. Washing removes 83% of benomyl residue from tomatoes and further processing reduces the residue by 98% in tomato puree and catsup. Even in the most concentrated fraction from tomatoes (tomato paste), residues were below the initial level in the raw product.
Liquid Chromatographic-Electrochemical Detection Screening Procedure for Six Nitro-Containing Drugs in Chicken Tissues at Low ppb Level
Authors: Parks Owen W 
Published: February 2020

Abstract
A screening procedure is described for the detection of furazolidone, nitrofurazone, aklomide, zoalene, nitromide, and sulfanitran residues in a single extract of chicken liver, breast, or thigh muscle at the low ppb level. The method includes extraction of tissue with chloroformethyl acetate-dimethyl sulfoxide (50 + 50 + 0.8), adsorption on neutral alumina, and subsequent elution of the residues with pH 6.0 phosphate buffer-methanol (1 + 1). Eluants are separated on a 25 cm, 5 fim Cj8 column with pH 6.0 phosphate buffer-methanol (57.5 + 42.5) as mobile phase. The drugs are detected with an electrochemical detector in the reductive mode at -0.8 V. Mean recoveries from all tissues ranged from 76.5% for nitrofurazone to 97.1% for zoalene.
Determination of iV-Methylcarbamate Pesticides in Liver by Liquid Chromatography
Authors: Ali Sher M 
Published: February 2020

Abstract
A liquid chromatographic (LC) method using a 2-step purification technique for the simultaneous determination of 10 carbamates in bovine, swine, and duck livers has been developed. Carbamates are extracted from liver samples with methylene chloride. After evaporation, the residues from the extract are dissolved in methylene chloride- cyclohexane (1 + 1) and cleaned up by gel permeation chromatography. The eluate containing carbamate residues is evaporated to dryness, reconstituted in methylene chloride, further purified by passing it through an aminopropyl Bond Elut extraction cartridge, and analyzed by liquid chromatography using post-column derivatization with orthophthalaldehyde and fluorescence detection. Excitation and emission are set at 340 and 418 nm, respectively. Liver samples for beef, pork, and duck were fortified with 5, 10, and 20 ppb of mixed carbamate standards. The average of 10 recoveries of 10 carbamates at all 3 levels of fortification was greater than 80% with coefficients of variation less than 17%.
Comparison Evaluation of Liquid Chromatographic and Bioassay Methods of Analysis for Determination of Paralytic Shellfish Poisons in Shellfish Tissues
Authors: Salter Julia E , Timperi Ralph J , Hennigan Laura J , Sefton Lynda , Reece Hilary 
Published: February 2020

Abstract
A liquid chromatographic (LC) method was compared with the AOAC mouse bioassay method (18.086-18.092) for determination of paralytic shellfish toxins in shellfish tissues. Shellfish samples were collected from Massachusetts coastal waters as part of a state surveillance program, and extracts of shellfish meat were analyzed for toxins by using both analytical methods. Overall correlation of the LC and bioassay methods is good (r = 0.943), but for samples with toxicities &lt; 100 jug saxitoxin/100 g shellfish meat, the correlation is significantly less (r = 0.531). Limits of detection are 10 fig saxitoxin/ 100 g shellfish meat and 40 fig saxitoxin/100 g shellfish meat for the LC and bioassay methods, respectively. Analytical capacity of the LC method is limited to 12 samples/person-day compared with 30 samples/ person-day for the bioassay. Sampling capacity of the LC method could be increased by using a fluorescence detector with a wider response range, which would eliminate the need for dilution of concentrated samples.
Net Contents of Packaged Beer: Summary of Collaborative Study
Authors: Gales Peter W 
Published: February 2020

Abstract
The net contents of packaged food and beverage products is a matter of regulatory concern. In the case of alcoholic beverages, net contents are regulated by various federal, state, and local agencies. With such a variety of controlling agencies, standardized and uniform methods are essential to avoid undue confusion. Collaborative studies were initiated within the American Society of Brewing Chemists in 1985 to determine the most appropriate methods for the determination of net contents of packaged beer. The work was completed in 1987. After collaborative testing of 5 methods over the 2-year period (ASBC JOURNAL (1987) 45, 114-117), 3 of the methods were found suitable: (1) total contents of cans of known tare weight; (2) total contents of bottles and cans by calculation from measured net weight; (J) deliverable contents of bottles and cans from measured net weight. These methods, which are recommended for adoption by AOAC, have been approved interim official first action.
Determination of Citrus Red No. 2 in Orange Peel by Liquid Chromatography Cynthia Hope And Russell Connors
Authors: Hope Cynthia , Connors Russell 
Published: February 2020

Abstract
A liquid chromatographic (LC) method is described for determina-tion of the color additive Citrus Red No. 2 in orange peel. The dye is extracted with petroleum ether using a Soxhlet-type apparatus. The extract is evaporated almost to dryness and the residue is dissolved in acetonitrile. Liquid chromatographic analysis is carried out, isocrati-cally, on an Ultrasphere ODS C18 column with acetonitrile-water (90 + 10) as mobile phase and detection at 504 nm. Recoveries from dried orange peel fortified at 3 levels ranged from 93 to 103%; recoveries from fresh orange peel ranged from 87 to 102%.
Comparison of Two Methods for Determination of Total Solids Content of Milk:
Collaborative Study
Authors: Clark Jenny L , Barbano David M , Dunham Chapman E 
Published: February 2020

Abstract
Ten laboratories analyzed 9 pairs of blind duplicate raw milk samples for total solids. A direct forced air oven method (4 h at 100°C) and a modification of the AOAC predry method (16.032) were used. Preliminary evaluation of the modified AOAC method indicated that blank determinations were necessary. Total solids content ranged from 12.0 to 14.6%. Average repeatability standard deviations (sr) of the direct forced air oven and modified AOAC methods were 0.019 and 0.017, respectively. Average reproducibility standard deviations (SR) of the direct forced air oven and the modified AOAC methods were 0.042 and 0.047, respectively. Average repeatability relative standard deviations (RSDr) for the direct forced air oven and the modified AOAC methods were 0.149 and 0.136%, respectively; average reproducibility relative standard deviations (RSDR) were 0.327 and 0.370%, respectively. Mean repeatability values (r) and reproducibility values (R) were 0,054 and 0.118 for the direct forced air oven method and 0.049 and 6.133 for the modified AOAC method, respectively. The mean test result of the direct forced air oven method (12.7293%) was comparable to that for the modified AOAC method (12.7273%). The modification of AOAC method 16.032 and the direct forced air oven method have been approved interim official first action.
Determination of Methyl Bromide in Foods by Headspace Capillary Gas Chromatography with Electron Capture Detection
Authors: Page Denis B , Avon Richard J 
Published: February 2020

Abstract
Methyl bromide (MB, bromomethane) is determined in a variety of foods by headspace capillary gas chromatography with electron capture detection. The comminuted food sample as an aqueous sodium sulfate slurry is equilibrated with stirring for 1 h at room temperature before a 1 mL headspace aliquot is removed and injected using a modified on-column syringe needle. Methyl bromide is cryogenically focussed at —60°C and then eluted by temperature programming. The procedure requires blending of soft samples, e.g. raisins, prunes, or oranges, and ultrasonic homogenization of hard samples, e.jv wheat, cocoa beans, corn, or nuts, with portions of water and ice so the final temperature of the food-water slurry is &lt; 1°C. A 20 g aliquot (4 g food) is then added to a cold headspace vial containing 4 g sodium sulfate. Losses of MB during a 3.5 min ultrasonic homogenization of wheat were 11% at 0.95 ppb and 4.4% at 4.8 ppb. For flour, cocoa, and finely divided spices, which do not require blending, 4 g is added to the cold headspace vial containing 16 mL cold water and 4 g sodium sulfate. Studies show that comminution of wheat or peanuts must be carried out to release MB trapped within the food so the headspace equilibrium can be attained in 1 h as well as to obtain homogenous samples and representative sampling. No interferences were noted with the above foods or with many grain-based baking mixes analyzed. Detection limits were shown to be generally dependent on the approximate lipid content of the food and ranged from 0.15 to 0.65 ppb (5% full scale deflection). Repeatability CVs for spiked or incurred MB in flour, wheat, and parmesan cheese at 0.60-96 ppb were &lt; 6.8%.
Chemical Characterization and Bioavailability of Phosphorus in Water-Insoluble Fractions of Three Mono-Ammonium Phosphate Fertilizers
Authors: Sikora F J , Dillard E F , Copeland J P , Mullins G L 
Published: February 2020

Abstract
Elemental impurities in mono-ammonium phosphate (MAP) fertilizers, such as Fe, Al, Ca, Mg, and F, result in compounds other than NH4H2PO4. The phosphorus availability of the impurity compounds was determined in 3 commercial MAP fertilizers produced from North Carolina, Florida, and Idaho phosphate rocks. Soluble compounds, including NH4H2PO4, were washed out of the fertilizers, and the water-insoluble fraction was collected. The North Carolina, Florida, and Idaho MAP fertilizers contained 13, 16, and 17% waterinsoluble fractions, respectively. Availability of phosphorus in each MAP fertilizer and water-insoluble fraction was determined in a greenhouse pot study using sorghum-sudangrass {Sorghum bicolor) as the test crop. There were no differences in dry matter weights or phosphorus uptake between reagent grade MAP and each MAP fertilizer. Lower dry matter weights and phosphorus uptake were produced from the water-insoluble North Carolina, Florida, and Idaho fractions (NC &gt; FL &gt; ID). Chemical analysis and characterization with optical microscopy, infrared spectroscopy, and X-ray diffractometry indicated 77.3,73.8, and 73.6% NH4H2PO4 in the North Carolina, Florida, and Idaho MAP fertilizers, respectively. MgAl(NH4)2H(P04)2F2, AINH4HPO4F2, and FeNH4(HP04)2 were identified as water-insoluble phosphorus compounds. There was a significant negative correlation between the percent phosphorus present as MgAl(NH4)2H(P04)2F2 and the phosphorus availability. Increased crystallinity of the various water-insoluble compounds also contributed to reduced phosphorus availability.
Hydrophobic Grid Membrane Filter/MUG Method for Total Coliform and E s c h e r ic h ia c o li Enumeration in Foods: Collaborative Study
Authors: Entis Phyllis 
Published: February 2020

Abstract
Twenty-four laboratories participated in a collaborative study to validate a hydrophobic grid membrane filter (HGMF) method incorporating the use of 4-methylumbelliferyl-/?-D-glucuronide (MUG) for enumeration of total coliform and Escherichia coli bacteria in foods by comparing its performance against the AOAC 3-tube MPN method (46.013-46.016). Raw milk, raw ground poultry, whole egg powder, cheese powder, and ground black pepper were included in the study. The total coliform methods did not differ significantly, except that the 3-tube method detected a significantly higher level of total coliforms than did the HGMF method in the ground black pepper. Conversely, the HGMF/MUG E. coli method detected significantly higher numbers of E. coli present in the egg powder, cheese powder, and ground black pepper samples, while not differing significantly from the 3-tube method for the raw milk and raw ground poultry samples. The overall confirmation rate of MUG-positive colonies isolated using the HGMF method was 99.5%. The hydrophobic grid membrane filter/MUG method has been adopted official first action as an additional method to AOAC official final action method 46.030-46.034.
Determination of Aflatoxin Concentrations in Peanut Butter by Enzyme-Linked Immunosorbent Assay (ELISA): Study of Three Commercial ELISA Kits
Authors: Patey Alan L , Sharman Matthew , Wood Roger , Gilbert John 
Published: February 2020

Abstract
Sixteen United Kingdom analytical laboratories participated in an evaluation of 3 commercially available enzyme-linked immunosorbent assay (ELISA) kits for analysis of aflatoxin in peanut butter. Each laboratory was sent 3 sets of 10 randomly numbered samples of peanut butter. Each set consisted of 5 pairs of undisclosed duplicates. Four of the sets of duplicates were naturally contaminated butters with “target” aflatoxin values (estimated by liquid chromatography) between 8 and 81 fig/kg. The fifth pair was a blank peanut butter containing approximately 3 fig/kg of total aflatoxins. A statistical treatment of the results of the study is presented, together with discussion of the relative merits of the different kits.
Determination of Linuron in Potatoes Using Capillary Column Gas Chromatography/Mass Spectrometry
Authors: Mattern Gregory C , Singer George M , Louis Judy , Robson Mark , Rosen Joseph D 
Published: February 2020

Abstract
A convenient method for the determination of the JV-methyl,iVmethoxy- phenylurea herbicide (linuron) in potatoes has been developed. The herbicide is extracted from potatoes using a slightly modifled Luke multiresidue procedure. The extract is analyzed directly by gas chromatography with cold on-column injection, using an ion trap mass spectrometer in the chemical ionization mode as the detector. Quantitation is performed using p-bromonitrobenzene as the internal standard. The limit of detection is 0.1 ppm. Recoveries of linuron in potatoes averaged 112 ± 6% at the 0.5 ppm level, and 110 ± 2% at the 0.2 ppm level. No linuron residues were found in 25 potato samples that were analyzed by this method. Two other iV-methyl,iV-methoxyphenylurea herbicides, metobromuron and chlorbromuron, are also sufficiently stable to be determined by this method, but the N,Ndialkyl- phenylurea herbicides neburon, diuron, and monuron are too thermally unstable and degrade in the gas chromatograph.
Enzymatic Hydrolysis of Biological and Environmental Samples as Pretreatment for Analysis
Authors: Forsyth D S , Iyengar J R 
Published: February 2020

Abstract
Four commercially available proteases were tested, in conjunction with a lipase, for efficacy in hydrolyzing 3 tissue substrates: cod fillet, chicken egg, and bovine liver. Enzymatic hydrolysis of tissues minimizes the formation of emulsions during liquid-liquid extraction and does not accelerate the decomposition of acid- or base-labile analytes. Recovery of hexane and benzene phases from the hydrolysates was also evaluated. Protease from Streptomyces griseus combined with lipase from Candida cylindracea (available commercially) produced the highest percent hydrolysis (relative to classical acid hydrolysis) in all 3 tested tissues (60-95%) and the greatest recovery of hexane (100%) and benzene (92-100%) solvent phases.