bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of Fluorene in Fish, Sediment, and Plants
Authors: Lebo Jon A , Smith Lawrence M 
Published: February 2020

Abstract
Methods and their applications are described for the determination of fluorene in fish, sediment, and plants. Sample extracts are enriched by using 2 or more of the following: gel permeation, silica gel, potassium silicate, sulfuric acid-impregnated silica gel, and activated carbon. Efficiency was improved by applying the adsorbents in combination or as tandem enrichment modules. Analyses by liquid chromatography (LC) with ultraviolet or fluorescence detection (LC/UV or LC/F) yielded limits of detection of 30, 3, and 30 ng/g and average recoveries of 80, 81, and 74% for fish, sediment, and plants, respectively.
Single-Laboratory Validation of EPA Method 8150 for Determination of Chlorinated Herbicides in Hazardous Waste
Authors: Gurka Donald F , Shore Fred L , Pan Shu-Teh , Amick E Neal 
Published: February 2020

Abstract
Method 8150, published in the second edition of Test Methods for Evaluating Solid Waste, Manual SW-846, required optimization, ruggedness testing, linearity determinations, precision tests, bias testing, gas chromatographic/mass spectrometric confirmation, and quality control guidelines for validation of the protocol. This single-laboratory validation, which is applicable to the determination of the herbicides dicamba, silvex, 2,4-D, 2,4-DB, 2,4,5-T, dinoseb, MCPP, MCPA, and dichlorprop in hazardous waste extracts, was completed and is described in this report. Final ruggedness testing of the optimized procedure gave a mean recovery of 89.3% with a standard deviation of 4.3%. Percent relative standard deviations are less than 10 (n = 20, each analyte) over a 102 linear range of concentration for MCPP and MCPA and over a 103 linear range of concentration for the other target herbicide esters. Instrumental detection limits for electron capture detection and mass spectrometric identity confirmation were determined and found to be matrix-dependent.
UV Spectrophotometry Determination of Piperine in Pepper Preparations: Collaborative Study
Authors: Lupina Ted , Cripps Howard 
Published: February 2020

Abstract
Eight collaborating laboratories performed replicate analyses for piperine on 5 samples representing pepper raw spice, oleoresins, and soluble seasonings. Piperine is extracted into ethylene dichloride and measured at maximal absorbance 342-345 nm with a UV light source. Piperine content is calculated using an absorbance factor derived from piperine. Intralaboratory coefficients of variation (CV0) ranged from 0.5 to 3.1%; interlaboratory coefficients of variation (CVX) ranged from 3.0 to 5.8%. The method has been adopted as an official method of the American Spice Trade Association and as an official first action method by AOAC.
Liquid Chromatographic Determination of Cyclopiazonic Acid in Poultry Meat
Authors: Norred William P , Cole Richard J , Dorner Joe W , Lansden John A 
Published: February 2020

Abstract
A liquid chromatographic procedure has been developed for the determination of cyclopiazonic acid (CPA) in poultry meat. CPA is extracted from ground meat with chloroform-methanol (80 + 20), partitioned into 0.1 N sodium hydroxide, acidified, and extracted into dichloromethane. An interfering component of meat is removed by transferring the dichloromethane extract to a minicolumn containing silica gel and washing the column with petroleum ether and chloroform. CPA is eluted with methanol-acetic acid (99 + 1), and subjected to ligand-exchange liquid chromatography. Recovery of CPA from 40 separate samples of meat spiked with CPA at levels from 0.016 to 15.6 ppm was 70.4 + 14.1%. Analysis of meat from a chicken orally dosed with 10 mg CPA/kg body weight revealed that 14.5% of the dose was in muscle 48 h after administration.
Fast and Sensitive Screening Method for Detection of Trichothecenes in Maize by Using Protein Synthesis Inhibition in Cultured Fibroblasts
Authors: Scossa-Romano Donata A , Bickel Regula E , Zweifel Ulrich , Reinhardt Christoph A , Luthy Jurg W , Schlatter Christian L 
Published: February 2020

Abstract
A fast and sensitive bioassay with hamster (BHK-21 C13) fibroblasts for the detection of toxic trichothecenes in maize is described. Cells are exposed to pure toxins or crude maize extracts for 30 min. The mixture is then incubated with [l-14C]-leucine for an additional 60 min and the radioactivity incorporated into the protein of the washed cells is determined. The sensitivity of the assay was in the nuige 1-10 ng/mL (or 50 ppb in maize) for T-2, HT-2, and diacetoxyscirpenol. At least 1000-fold higher concentrations of non-trichothecene mycotoxins and plant toxins were necessary to cause an inhibition of protein synthesis in the cells. Of 24 maize samples tested, 14 gave a positive response in this assay and the presence of trichothecenes could be confirmed chemically in 11 samples. Therefore, the described bioassay is proposed as a useful screening method for cytotoxic trichothecenes in maize.
Determination of Adulterated Natural Bitter Almond Oil by Carbon Isotopes
Authors: Krueger Dana A 
Published: February 2020

Abstract
Bitter almond oil (benzaldehyde), a flavoring compound used in many foods, was isolated from apricot kernels; 2 synthetic benzaldehyde samples were obtained from commercial sources. All samples were analyzed for radiocarbon (l4C) content. The natural sample yielded a value consistent with its natural origin (approximately 116% of Modern Standard Activity), while the synthetic samples were devoid of 14C activity as expected for a petrochemical material. Implications for quality control of bitter almond oil are discussed
Headspace Gas Chromatographic Determination of Residual 1,3-Butadiene in Rubber-Modified Plastics and Its Migration from Plastic Containers into Selected Foods
Authors: Mcneal Timothy P , Breder Charles V 
Published: February 2020

Abstract
A headspace gas chromatographic procedure has been developed for the determination of 1,3-butadiene in rubber-modified plastics and in some foods. Polymer solutions or foods are equilibrated in sealed vials at 90°C, and headspace samples are injected into a gas chromatograph. 1,3-Butadiene residues are measured using a flame ionization detector and are quantitated by the method of standard additions or an external calibration curve. Refrigerator tubs, vegetable oil bottles, chewing gum, and foods in contact with this type of packaging were analyzed. Limits of quantitation varied with the matrix, ranging from 2 ng/g (ppb) in chewing gum to 20 ng/g in polymers. 1,3-Butadiene was found in one polymer at 53 ng/g with an 8% coefficient of variation. The procedure yields "apparent" trace levels of 1,3-butadiene, and confirmation by a complementary technique is required.
Rapid Determination of Methyl Mercury in Fish and Shellfish: Method Development
Authors: Hight Susan C , Corcoran Mary T 
Published: February 2020

Abstract
The AOAC official first action method for methyl mercury in fish and shellfish was modified to provide more rapid determination. Methyl mercury is isolated from homogenized, acetone-washed tissue by addition of HC1 and extraction by toluene of the methyl mercuric chloride produced. The extract is analyzed by electron capture gas chromatography (GC) on 5% DEGS-PS treated with mercuric chloride solution. The quantitation limit of the method is 0.25 μg Hg/g. Swordfish, shark, tuna, shrimp, clams, oysters, and NBS Research Material-50 (tuna) were analyzed for methyl mercury by the AOAC official first action method. All products also were analyzed by the modified method and the AOAC official method for total Hg. In addition, selected extracts obtained with the modified method were analyzed by GC with Hg-selective, microwave-induced helium plasma detection. There was no significant difference between the results for the various methods. Essentially all the Hg present (determined as total Hg) was in the organic form. Coefficients of variation from analyses by the modified method ranged from 1 to 7% for fish and shellfish containing methyl mercury at levels of 0.50-2.30 μg Hg/g. The overall average recovery was 100.5
Gas Chromatographic Method for Determination of Cypermethrin in Pesticide Formulations: Collaborative Study
Authors: Tyler J F C 
Published: February 2020

Abstract
A gas chromatographic method for determination of total cypermethrin in technical and formulated products has been developed and subjected to a collaborative study involving IS participating laboratories. Each sample was dissolved in methyl isobutyl ketone containing di(2-ethylhexyl) phthalate as internal standard and analyzed by gas chromatography on a glass column with 3% OV-101 on Chromosorb W-HP. Each collaborator was furnished with reference stdard and 4 samples of technical material, 3 emulsifiable concentrates, one wettable powder, and one ultralow volume formulation for analysis. The coefficients of variation of the results obtained ranged from 0.955 to 1.7462%. The method has been adopted as official first action by AOAC.
Gas Chromatographic-Thermal Energy Analysis Method for Determination of Volatile N-Nitrosamines in Baby Bottle Rubber Nipples: Collaborative Study
Authors: Gray J Ian , Stachiw Michael A 
Published: February 2020

Abstract
A collaborative study was conducted on the U.S. Food and Drug Administration (FDA) dichloromethane extraction method for determining volatile N-nitrosamines in baby bottle rubber nipples. Following dichloromethane extraction, A'-nitrosamines were determined by gas chromatography-thermal energy analysis. Six pairs of blind duplicate rubber nipple samples representing 6 lots were analyzed by 11 collaborating laboratories. All samples were portions taken from equilibrated composites of cut-up rubber nipples obtained from manufacturers in the United States. Recoveries of the internal standard (N-nitrosodipropylamine) at approximately 20 ppb ranged from 10 to 120%. Reproducibility relative standard deviations (RSDJ were between 35 and 45% for N-nitrosamine levels from 10 to 20 ppb. However, when data from laboratories with recoveries less than 75% were excluded (this is now specified in the method), RSD„ values were between 11 and 32% for N-nitrosamine levels from 6 to 26 ppb. Values were consistent with or better than those reported for other analytical techniques designed to quantitate trace contaminants at the low ppb level, e.g., afiatoxin in foods. The method has been adopted official first action for the quantitation of volatile N-nitrosamines in baby bottle rubber nipples.
Chemical Analysis of Meat Products
Authors: Ellis Richard L 
Published: February 2020

Abstract
Meat, particularly muscle tissue, is basically a 3-component system of protein, moisture, and fat. Although this seems a simple analytical system in which to monitor product composition for regulatory compliance, the simplicity quickly erodes when meat is formulated into the broad variety of products commercially available today. Alternative protein sources, as well as preservatives, binders, extenders, emulsifiers, spices, and other flavoring ingredients, add to the analytes of concern and highlight the need for analytical methods suitable to support inspection and labeling requirements to ensure product compliance. Some key issues are noted which involve protein quality analysis, rapid compositional analysis, isolated soy protein analysis, and minced fish in meat products.
Comparison of Modified Automatic Dumas Method and the Traditional Kjeldahl Method for
Nitrogen Determination in Infant Food
Authors: Bellomonte Guido , Costantini Anna , Giammarioli Stefania 
Published: February 2020

Abstract
This study compares 2 methods for determining nitrogen and protein in various types of infant food: the Kjeldahl method, developed in 1883, which is time consuming and labor intensive, and a newer, automatic method, based on the Dumas method. In each category of infant food considered, the results obtained from both methods are shown to be comparable; however, the modified Dumas method is quicker, easier, and does not pollute the laboratory environment
Amino Acid Analysis by Capillary Gas Chromatography
Authors: Zumwalt Robert W , Desgres Jean , Kuo Kenneth C , Pautz James E , Gehrke Charles W 
Published: February 2020

Abstract
Two developments have enabled major advancements in the use of capillary gas chromatography (GC), the result being its much more widespread use in investigations on a broad range of chemical and biological problems. The 2 technological developments were the introduction of fused silica capillary columns and the development of immobilized stationary phases for capillary GC columns. Because fused silica columns with immobilized stationary phases of varying polarities are offered by numerous vendors of chromatographic equipment, they have become widely used for many analytical tasks. We conducted a study to compare the effectiveness of commercially available fused silica capillary columns with the classical ion-exchange method in the separation and quantitation of amino acids. We selected the /V-trifluoroacetyl (TFA) n-butyl and the A'-heptafloorobutyryl (HFB) isobutyl ester derivatives for this study because of the extensive research and application of these derivatives during the past 20 years. The amino acid content of hydrolysates of 5 materials was measured: ribonuclease,β-lactoglobulin, lysozyme, soybean meal, and a commercial poultry feed. Single 6N HC1 hydrolysates of each material were prepared to minimize sample preparation differences, and 3 independent analyses of each hydrolysate were made by each of 3 techniques: the N-TFA n-butyl and N-HFB isobutyl ester methods using capillary gas chromatography and the ion-exchange chromatographic method using a Beckman 121 M amino acid analyzer. Our results clearly demonstrate that capillary GC analysis of amino acids using fused silica bonded-phase columns provides data with good precision and in general excellent agreement with ion-exchange analyses.
Capillary Column Gas Chromatographic Determination of Trace Residues of the Herbicide Chlorsulfuron in Agricultural Runoff Water
Authors: Ahmad Uaz 
Published: February 2020

Abstract
A capillary column gas chromatographic method is described for determining parts-per-trillion (ppt) levels of chlorsulfuron in agricultural runoff water. The water sample is acidified with acetic acid and extracted with methylene chloride. The chlorsulfuron in the extract is derivatized to its monomethyl derivative. After Florisil column cleanup, the methylated chlorsulfuron is determined by electron-capture gas chromatography. Recovery of chlorsulfuron from fortified water samples is greater than 80%. Detection limit of the method is 25 ng chlorsulfuron/L water (25 ppt). There are 2 reaction sites on the chlorsulfuron molecule, both of which are susceptible to methylation leading to monomethyl chlorsulfuron and dimethyl chlorsulfuron. A procedure is described to methylate selectively the sulfonamide nitrogen of chlorsulfuron.
Determination of Several Halogenated Fumigants in Cereal Products by Steam Distillation and Capillary Gas Chromatography with Electron Capture Detection
Authors: Page Denis B , Newsome Harvey W , Macdonald Stephen B 
Published: February 2020

Abstract
A steam distillation procedure is described for the determination of ethylene dibromide (EDB), ethylene dichloride (EDC), and carbon tetrachloride (CT) in flour, flour-based mixes, baked cakes, breakfast cereals, and citrus fruits. A representative sample is steam distilled using a modified Garman steam distillation apparatus, the steam and volatile components are condensed, and the condensate is partitioned with hexane (EDB) or pentane (EDC and CT). The solvent extract is then injected on-column and analyzed by using a 15 m x 0.32 mm 1.0 μ DB-1701 fused-silica capillary column at 50°C for EDB or a 30 m x 0.25 mm 1.0 μ DB-5 column at 35°C for EDC and CT. For routine EDB determinations as low as 10 ppb, 2 g flour, Hour-based mix, or breakfast cereal is distilled and partitioned into 10 mL hexane. For enhanced sensitivity, up to 10 g dry sample can be concentrated into 1 mL hexane, for detection as low as 0.1 ppb (10% FSD, 2.0 pg). Recoveries from flour spiked with 100, 5, and 0.5 ppb EDB were 98.9, 95.1, and 117%, respectively. Coefficients of variation for marketplace flour samples found to contain EDB at 122,6.0, and 1.2 ppb were 4.6,6.9, and 3.6%, respectively, and for baby cereal at 0.22 ppb, 4.5%. Recoveries for EDC and CT from flour spiked at 46, 94, and 140 ppb were 61,73, and 72%, and 96,95, and 87%, respectivefy. Coefficients of variation were 10.0, 7.8, and 4.8, and 8.0, 3.2, and 8.4%, respectively
Fluorimetric Determination of Anatoxin M1 in Cheese
Authors: Bijl Jan P , Van Peteghem Carlos H , Dekeyser Diana A 
Published: February 2020

Abstract
A simple and sensitive method is proposed for the determination of aflatoxin M, in cheese. The ground cheese sample is extracted with acetone-water (3 + 1). Acetone is evaporated under vacuum, and the aqueous phase is passed through a C18 disposable cartridge. After the cartridge is washed with acetonitrile-water (1 + 9), the toxin is eluted with acetonitrile. The extract is then cleaned up on a silica cartridge. Final analysis is performed by 2-dimensional thin layer chromatography (TLC) combined with fluorodensitometry or by liquid chromatography on a reverse phase C„ column with fluorescence detection. Recovery is greater than 90%, and the coefficient of variation is 6% or less. The detection limit is in the range of 10 ng/kg. The identity of aflatoxin M2, is confirmed by formation of the Mu or acetyl-M1, derivative and rechromatography.
Identification of Mammalian Feces by Thin Layer Chromatography of Coprostanol: Collaborative Study
Authors: Hoskin George P 
Published: February 2020

Abstract
Mammalian feces contain coprostanol (5β-cholestan-3/J-ol). In this study, 7 collaborators each tested 45 unknown specimens by a thin layer chromatographic method that uses coprostanol as an indicator of feces. The materials tested were 5 replicates each of 3 test portion sizes (0.5,1.0, and 5.0 mg) of cockroach excreta (negative), and cow and rat feces (both positive). Of 315 specimens tested, 261 (82.9%) were correctly identified; there were 5 false positives, 26 false negatives, and from 1 collaborator, 23 inconclusive results.
Development of Milk Powder Reference Materials Certified for Aflatoxin M1 Content (Part I)
Authors: Egmond Hans P Van , Wagstaffe Peter J 
Published: February 2020

Abstract
The development of 3 full-cream milk powder reference materials, certified for their aflatoxin M1 content, is described. The materials were prepared and certified within the Reference Material Programme of the Community Bureau of Reference (BCR). The 3 reference materials, RMs 282, 284, and 285, contain aflatoxin M1 at concentrations of &lt;0.05, 0.31 ± 0.06, and 0.76 ± 0.05 μg/kg, respectively. The preparation, testing for homogeneity, stability of the reference materials, and the certification exercise, which was preceded by 2 intercomparisons of methods, are discussed. Particular emphasis was placed on the independence of the measurements in the certification exercise and the control of errors associated with extraction efficiency and the aflatoxin M1 calibrant. Finally, some guidance is given on avoiding the principal sources of error in the determination of aflatoxin M1. Details concerning the supply of the reference materials will be provided by BCR on request.
Recommendations for Establishment of Reference Standards for Recombinant-DNA-Derived Proteins and Polypeptides
Authors: Atkins Lois M , Miner David J , Sittampalam G Sitta , Wentling Charles D 
Published: February 2020

Abstract
An integrated approach is presented for the establishment of purified protein and peptide reference standard materials suitable for both biological and chemical assays. Preliminary considerations, handling and storage conditions, and a variety of chemical methods for defining the reference standards are examined in detail. Of the chemical methods, liquid chromatography (LC), amino acid analysis, Kjeldahl protein assay, electrophoresis, and ion chromatography are key assays in determining the potency, purity, and identity of the reference standard preparation. Finally, the role of liquid chromatography in assessing reference standards for identity and chemical purity is examined and correlated with other methods.
Phase Solubility Analysis of Some Organochlorine Fungicides
Authors: Lesser Joseph H , Massil Solomon E 
Published: February 2020

Abstract
Phase solubility analysis (PSA) was used to establish purities of 3 organochlorine fungicides—chlorothalonil, captan, and folpet. Each ground sample was added to an equal amount of solvent. All vials were mixed at identical constant temperature, equal aliquots of liquid phase were removed and weighed, and concentration of dissolved material was determined by weighing the residue after evaporation to a constant weight. Solvent systems were chosen such that solubility of the fungicides was minimal. Data were analyzed by the leastsquares method with a resulting correlation coefficient of better than 0.94. Spiking experiments were also performed. Analysis of chlorothalonil by differential scanning colorimetry and of captan and folpet by liquid chromatography was in accord with PSA results.
Interlaboratory Study of Blood Selenium Determinations
Authors: Koh Tee-Siaw 
Published: February 2020

Abstract
Fifty-one laboratories from 14 countries participated in a survey on the determination of selenium (Se) in 8 bovine blood samples with Se concentrations ranging from 0.2 μmol/L (0.016 μg/mL) to 14 μmol/L (1.1 μg/mL). The methods used (and the percentage of participants using each method) were fiuorometry (61), hydride-generation atomic absorption spectrophotometry (AAS) (23), graphitefurnace AAS (6), gas chromatography (4), neutron activation analysis (4), and X-ray fiuorometry (2). There was little difference in the mean Se results obtained by fiuorometry or hydride-generation AAS (P &gt; 0.05). Mean intralaboratory coefficients of variation (CVs) from known replicates ranged from 4 to 14% for all samples. Interlaboratory CVs were related to blood Se concentration and increased to 55% at Se levels below 0.4 μmol/L (0.032 μg/mL). Laboratories that used quality control (QC) schemes had lower interlaboratory CVs than those that did not, but the advantage began to diminish at blood Se concentration below 0.4 μmol/L (0.032 μg/mL). The high interlaboratory CVs, coupled with the false assurance from the low intralaboratory CVs and the ineffectiveness of the QC schemes at blood Se concentrations below 0.4 μmol/L (0.032 μg/mL), are of concern in diagnosis of marginal Se deficiency in livestock where the concentrations of interest are in the range 0.15-0.5 μmol/L (0.012-0.039 μg/mL).
New Method for the Determination of 1,1-Dimethylhydrazine Residues in Apples and Peaches
Authors: Wright Dallas 
Published: February 2020

Abstract
A new method for determining 1,1-dimethylhydrazine (UDMH) in peaches and apples is presented. The method consists of extraction with L-ascorbic acid, derivatization with 2-nitrobenzaldehyde to the corresponding hydrazone, and cleanup on an alumina column. The hydrazone derivative is determined by gas chromatography using an electron-capture detector. Recoveries were determined from 10 to 100 ppb. Stability of the UDMH residues on frozen peaches was investigated, and results indicate that the residues degrade even while frozen.