bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of a Multispecies Identification Field Test by Modified Agar-Gel Immunodiffusion
Authors: Cutrufelli Mark E , Mageau Richard P , Schwab Bernard , Johnston Ralph W 
Published: February 2020

Abstract
A multispecies identification field test (MULTI-SIFT) was developed for detection of beef, poultry, pork, sheep, horse, and deer in a wide variety of raw meat products. The test is an adaptation of previously developed field screening immunodiffusion tests for detection of single species. MULTI-SIFT was demonstrated to be specific, relatively sensitive, and accurate in the complete speciation of 100 meat samples.
Determination of Biogenic Amines in Beers and Their Raw Materials by Ion-Pair Liquid Chromatography with Postcolumn Derivatization
Authors: Izquierdo-Pulido M L , Vidal-Carou M C , Marine-Font A 
Published: February 2020

Abstract
A liquid chromatographic method is described for the determination in one run of the following 10 biogenic amines in beers: histamine, tyramine, serotonin, (β-phenylethylamine, tryptamine, cadaverine, putrescine, agmatine, spermine, and spermidine. The method is based on ion-pair chromatographic partition on a reversed-phase column and involves a postcolumn reaction with o-phthalaldehyde (OPT) to form fluorescent derivatives with amines. Treatment of beer samples before injection requires only a filtration through a 0.45 μm filter. It is necessary to obtain a perchloric extract for analysis of raw materials (malt and hops). The method was tested for lack of interference from amino acids and other amines. Linearity, precision, recovery, and sensitivity were satisfactory. Detection limits ranged from 0.30 to 0.40 mg/L, and determination limits ranged from 0.40 to 0.50 mg/L, except for serotonin and spermine, which were slightly higher. The simple preparation of sample and the automatic accomplishment of derivatization steps considerably reduce analysis time and effort.
Gas Chromatographic Determination of Cyclohexanone Leached from Hemodialysis Tubing
Authors: Snell Robert P 
Published: February 2020

Abstract
A capillary gas chromatographic procedure is described for the determination of cyclohexanone leached from hemodialysis tubing by water. Recoveries were 100% at 2.0 mg/100 mL (20 ppm), 99.0% at 500 μg/100 mL (5 ppm), and 106% at 1.0 μg/100 mL (10 ppb). Reproducibility of the system was 0.152% for 3.0 μL injections of a solution containing cyclohexanone at 5.58 μg/mL. Correlation coefficients were 0.9983 for 0.3672-3.672 ng and 1.0000 for 3.672-367.2 ng. Twenty hemodialysis tubing sets from 4 manufacturers were examined. The leachable cyclohexanone ranged from 1.02 to 43.7 ppm per set. Rinsing the tubing with 1 L 0.9% sodium chloride solution did not remove significant amounts (P = 0.05) of leachable cyclohexanone.
Rapid Thin-Layer Chromatographic Microestimation of Elemental Sulfur: Application to Complex Sulfur Ointments
Authors: Sanyal Asis K , Chowdhury Bhabadeb , Banerjee Arun B 
Published: February 2020

Abstract
Because of its nonpolar character, elemental sulfur can be separated easily from the components of complex samples and quantitated by thin-layer chromatography. Sulfur was separated by petroleum ether on silica gel G layers. The sulfur band on the chromatogram was scraped off and eluted with chloroform, and sulfur was estimated by its absorbance at 265 nm. The present method allows rapid, simple, but highly sensitive detection of sulfur down to 1 μg on the plate. The method was applied with high accuracy and precision to the analysis of complex sulfur ointments. No interference was encountered from other active components usually present in such complex formulations.
Evaluation of Current AOAC Fertilizer Sample Preparation Requirements
Authors: Newlon Natalie , Cox-Trout Candace , Kane Peter 
Published: February 2020

Abstract
The official AOAC fertilizer sample preparation requires that all dry mixtures be ground to pass a U.S. No. 40 sieve. With current fertilizers and mechanical grinders, these criteria may no longer be appropriate. Blended fertilizers were ground and sieved, and the fractions were analyzed separately to show potential variability in results. In general, potassium was heavily concentrated in the smaller particles of the ground sample, whereas phosphorus tended to be concentrated in the coarser particles. A representative set of fertilizers was subjected to 7 grinding treatments designed to produce samples with a wide distribution of particle size. N, P, and K were determined in the samples by traditional methods. Analysis of the results demonstrated that precise, accurate results could be obtained from samples that did not technically meet current sample preparation requirements. The relationship between fineness of grind and size of the analytical sample portion was examined. With proper sample grinding, sample sizes of ≤20 mg could give representative results for nitrogen analysis, with precision equal to or better than traditional Kjeldahl analysis using 1 g samples. This is of particular interest, because various combustion instruments now becoming popular for nitrogen analysis are limited in sample size.
Effectiveness of the Bacteriological Analytical Manual Culture Method for the Recovery of Shigella sonnei from Selected Foods
Authors: June Geraldine A , Sherrod Patricia S , Miguel Amaguana R , Andrews Wallace H , Hammack Thomas S 
Published: February 2020

Abstract
The relative retention of the indigenous morphological, biochemical, and serological characteristics by Shigella sonnei was tested under various storage conditions (room temperature, refrigeration, freezing at −20°C and at −70°C, and lyophilization). The use of a selective (desoxycholate citrate) agar rather than a nonselective (brain heart infusion) agar gave a lower conversion rate of smooth to rough colonies, and the percentage of rough colonies derived from cultures stored for prolonged periods increased under all conditions. With respect to biochemical characteristics, there were no major differences in the reactions of smooth vs rough variants. For serological characteristics, smooth variants agglutinated more readily in homologous antisera than did rough variants. S. sonnei populations maintained at −70°C with glycerol remained reasonably stable and were used in recovery studies. Up to six foods (potato salad, chicken salad, cooked salad shrimp, lettuce, raw ground beef, and raw oysters) were inoculated with unstressed, chill-stressed, or freeze-stressed S. sonnei cells. Test portions (25 g) were inoculated with serial 10-fold dilutions of culture and subsequently analyzed by the culture method described in the U.S. Food and Drug Administration’s Bacteriological Analytical Manual. It was found that the method was relatively ineffective for the recovery of S. sonnei from raw ground beef and raw oysters.
Speciation Analysis of Organolead Compounds in Wine by Capillary Gas Chromatography/Microwave-Induced-Plasma Atomic Emission Spectrometry
Authors: Lobinski Ryszard , Szpunar-Lobinska Joanna , C. Adams Freddy , Teissedre Pierre-Louis , Cabanis Jean-Claude 
Published: February 2020

Abstract
A method was developed for the speciation analysis of ionic organolead compounds in wine. The analytes were extracted as diethyldithiocarbamate complexes into hexane and propylated with a Grignard reagent. The derivatized extract was analyzed by capillary gas chromatography/microwave-induced-plasma atomic emission spectrometry. The method of standard additions was used for calibration to correct for variable recoveries and signal en hancements. Red, rosé, and white wines from southern France were analyzed. Trimethyllead was the ubiquitous species. The wines made from grapes grown close to industrial zones showed elevated concentrations of ethyllead species. The con centrations of methyllead and ethyllead found in wines were compared with the concentrations of organolead found in rain water and plant sap collected in the viticultural regions. The ratio of methyllead to ethyllead in wines greatly exceeded the same ratio found in atmospheric deposits.
Determination of Volatile Chemicals Released from Microwave-Heat-Susceptor Food Packaging
Authors: Mcneal Timothy P , Hollifield Henry C 
Published: February 2020

Abstract
Microwave heat susceptors that convert electromagnetic energy to heat attain high temperatures that make it possible to cook some foods to golden crispness in a microwave oven. Susceptors are typically packaged with foods intended for microwave use, e.g., waffles, pizzas, and french fries. The high temperatures &gt;302°F used to cook some foods release trace levels of volatile chemicals from metalized polyester film, adhesive, and paper packaging materials; these volatile chemicals may be absorbed by the food. We simulated microwave susceptor cooking conditions and developed protocols by using headspace concentration capillary gas chromatography and mass spectrometry to identify volatile chemicals released from heated susceptors. We purchased a limited, cross-sectional sample of local retail microwave food products packaged with susceptors and used our protocol to analyze 10 different susceptor products. Although more than 140 unique chromatographic peaks were tabulated, only 44 volatile chemicals were identified, including 1,1,1-trichloroethane, benzene, and 2-(2-butoxyethoxy)ethanol, which were derived primarily from the paper and adhesive susceptor components. No one susceptor contained all the identified substances. The standard additions technique was the preferred method for quantitation. Trichloroethane and 2-(2-butoxyethoxy)ethanol were present in several products at 75-122 μg/in.2 of susceptor surface area. Benzene was found in 3 susceptors at ≤0.22 μg/in.2 levels. Examination indicates that adhesives used in more recent susceptor products were reformulated to remove even this trace level of benzene.
Method Modification for Liquid Chromatographic Determination of Thiamine, Riboflavin, and Pyridoxine in Medical Foods
Authors: Chase G William , Landen William O , Soliman Abdel-Gawad M , Eitenmiller Ronald R 
Published: February 2020

Abstract
A reversed-phase ion pair liquid chromatographic method developed for the simultaneous determination of thiamine (B1), riboflavin (B2), and pyridoxine (B6) in perchloric acid extracts of infant formulas was modified to include medical foods. UV detection of B1 and B2 was replaced by fluorescence detection, which resulted in improved sensitivity and specificity. B1 was detected by fluorescence after conversion to thiochrome by a postcolumn reaction with sodium hydroxide and potassium ferricyanide. The method uses a mobile phase of water, acetonitrile, hexanesulfonic acid sodium salt, ammonium hydroxide, and phosphoric acid adjusted to pH 3.6. The column is a 300 × 3.9 mm Nova Pak C18. Limits of detection were 0.05 μg/mL for B1 and B2 and 0.01 μg/mL for B6 by fluorescence detection. The system reproducibility was evaluated by completing 10 repetitive determinations on a medical food that gave a coefficient of variation of 5.9, 6.0, and 10.7% for B1, B2, and B6, respectively. Mean recoveries (n = 10) were 111,96.3, and 113% for B1, B2, and B6, respectively. The results compared favorably with those by AOAC Official Methods 942.23, 940.33, and 961.15 for B1, B2, and B6, respectively.
Partial Automation of Microbiological Assays for Vitamins
Authors: Haggett T O Richard , Matheson Alan R , Harnett Michelle 
Published: February 2020

Abstract
The dispensing and turbidity measurement steps used in microbiological assays of B group vitamins were automated by the use of a Gilson hardware package, a specially constructed turbidimeter, an IBM PC-AT or compatible computer, and software written in-house to facilitate data entry, control the hardware, and calculate the results. Considerable improvement in the speed and precision of the turbidity measurement was achieved (1% compared to 3-12%). The precision of the dispensing operation was better than that of manual dispensing (0.02-0.8% compared to 0.4-2%), although the speed was not improved. However, results and errors obtained from the automated system did not significantly differ from those obtained by former procedures. This was attributed to growth response variations not related to the automated procedure. The automation process facilitated detection of errors and halved the operator time per assay.
Analyte Stability Study of N-Methylcarbamate Pesticides in Beef and Poultry Liver Tissues by Liquid Chromatography
Authors: Ali M Sher , White Jerry D , Bakowski Ralph S , Phillippo Evan T , Ellis Richard L 
Published: February 2020

Abstract
To optimize conditions for sample collection, preparation, storage, and analysis and to assure the validity of our previously published liquid chromatographic (LC) method for carbamate analysis in tissue, stabilities of 16 N-methylcarbamates in beef, duck, and chicken liver tissues were studied by using 2 sampling protocols. Tissue samples were fortified at room temperature to a concentration 5 to 10 times greater than either the Environmental Protection Agency tolerance level for each compound (if established) or the concentration used in the previously published method. Thereafter, samples were continuously frozen at -4°C for varying time intervals. In the first study, samples were analyzed one day (initial) and 0.5, 1, 1.5, 2, 3, 4, 5, and 6 months after fortification. In the second study, samples were analyzed one day (initial) and 0.5, 1,2,3, and 6 months after fortification. For each residue and species, a minimum of 4 samples were analyzed by LC at each point in time, and the mean represented analyte concentration at the end of each time interval. Rates of residue depletion varied among analytes and among species. Depletion rates were greater in duck livers than in beef livers. Methomyl and oxamyl were depleted completely within 2 weeks. Between 2 and 6 months after sample fortification, residue depletions to levels below detection limits were observed for aldicarb, aldicarb sulfoxide, aldicarb sulfone, dioxacarb, promecarb, propoxur, and bendiocarb. The initial loss of certain carbamates during sample preparation in tissues exposed to room temperature for up to 8 h was greater than the subsequent rate of loss. Results indicate that cryogenic conditions are required for sample preparation and storage. Results also provide information on how long a violative evidentiary sample can be stored for potential litigation.
Confirmation of Identities of Propylene and Ethylene Glycols in Anchovies by Tandem Mass Spectrometry
Authors: Matusik Jean E , Eilers Paul P , Waldron Ellen M , Conrad Steve M , Sphon James A 
Published: February 2020

Abstract
A gas chromatographic/tandem mass spectrometric (GC/MS/MS) method has been developed for confirming the identity of propylene and ethylene glycols added to bait fish for preservation. Bait fish are occasionally illegally diverted to human food use. The bait fish were extracted with methanol, the extract was centrifuged and filtered, and the filtrate was concentrated 10-fold and then analyzed by GC/MS/MS. The glycols were separated chromatographically without derivatization or preliminary cleanup. Isobutane positive ion chemical ionization was used to generate the protonated molecular ion species of each glycol. Product-ion MS/MS experiments were performed to obtain spectra to confirm the identities of propylene and ethylene glycols. The identities of these 2 compounds in anchovy extracts were successfully confirmed by this approach.
Determination of Streptomycin and Dihydrostreptomycin in Animal Tissue by On-Line Sample Enrichment Liquid Chromatography
Authors: Gerhardt Geoff C , Salisbury Craig D C , MacNeil James D 
Published: February 2020

Abstract
A method for the determination of streptomycin and dihydrostreptomycin in pork and bovine muscle and kidney was developed. Dilute perchloric acid solution is used to precipitate proteins and extract the analytes from the tissue. The extract is loaded onto a cation-exchange, solid-phase extraction column, and the drugs are eluted with pH 8 phosphate buffer. The eluant is chromatographed by using an on-line column enrichment liquid chromatographic system with postcolumn derivatiza-tion using 1,2-naphthoquinone-4-sulfonic acid and detection by fluorescence. The recoveries were 61.1% (coefficient of variation [CV], 7.3%) for streptomycin and 55.3% (CV, 8.2%) for dihydrostreptomycin. The detection limits were 10 ppb for streptomycin and 20 ppb for dihydrostreptomycin.
Iron Milk Medium Method for Recovering Clostridium perfringens from Shellfish: Collaborative Study
Authors: Abeyta Carlos , Wetherington June H 
Published: February 2020

Abstract
Eleven laboratories participated in a collaborative study analyzing shellfish (oysters, Crassostrea gigas) for the detection and enumeration of Clostridium perfringens by the iron milk medium (IMM) method. The IMM method was compared to AOAC Official Method 976.30. Shellfish were artificially inoculated with C. perfringens cells (vegetative and spores) at low (1 × 103 colony forming units [cfu]/g), medium (1 × 104 cfu/g), and high (1 × 106 cfu/g) levels. Negative controls (zero level) were analyzed by each laboratory. C. perfringens FD-1, the strain involved in a foodborne illness, was used. Blind duplicates of each inoculum level were analyzed, giving a total of 16 samples per laboratory. The selectivity of IMM relies solely on the rapid growth of C. perfringens at 45°C indicated by stormy fermentation reaction within 18 h. C. perfringens is detected and enumerated using the most probable number technique. A statistical evaluation of the data found no significant differences between the estimates from the 2 methods. The IMM method for detection of C. perfringens from shellfish has been adopted first action by AOAC INTERNATIONAL.
Visual Screening with Enzyme Immunoassay for Staphylococcal Enterotoxins in Foods: Collaborative Study
Authors: Bennett Reginald W , McClure Foster 
Published: February 2020

Abstract
Selected foods containing 4–10 ng each of a mixture of Staphylococcus aureus enterotoxin serotypes A–E were tested by 15 collaborators. An enzyme-linked immunosorbent assay (EIA) was used with polyvalent antisera to these serotypes in a polyclonal antibody double “sandwich” configuration. Controls were free of toxin. Foods (25 g test samples) were homogenized with Tris (0.25M, pH 8.0) and centrifuged. The food extract was filtered through cotton and mixed with sample additive. For the EIA, 200 μL aliquots of the treated extracts were added to previously washed microtiter wells coated with antibody to staphylococcal enterotoxin serotypes A–E. Wells were washed and treated with the polyvalent antisera (A–E)-enzyme conjugate, and then washed again. Substrate was added, and wells were incubated. After incubation, stop solution was added. Results were determined visually and by measuring absorbance using a microtiter plate reader. In foods containing enterotoxin, bluish-green color was developed (positive result). Test solutions with absorbances &gt;0.200 were considered positive; those with absorbances ≤0.200 were negative. The method is sensitive and specific, and allows the rapid assay of staphylococcal enterotoxins in foods without differentiating their serotypes. The method has been adopted first action by AOAC INTERNATIONAL.
Identification of Hairs of Three Asian Commensal Mammals: Suncus murinus, Bandicota bengalensis, and Rattus exulans
Authors: Bryce John R 
Published: February 2020

Abstract
Hairs of 3 major Asian commensal mammals, Suncus murinus (L.), Bandicota bengalensis (Gray and Hardwicke), and Rattus exulans (Peale), were studied, identified, and compared with those of better-known commensal species to provide an overview of their hair morphologies. Techniques were developed for authentic hair specimen collection and rapid slide mounting to aid in the timely analysis of food products. The study showed that hairs of B. bengalensis and R. exulans are easily identified to the regulatory category of “rat or mouse hair,” whereas identification of S. murinus contaminant hairs is possible to the species level.
PAH RIS® Soil Test—A Rapid, On-Site Screening Test for Polynuclear Aromatic Hydrocarbons in Soil
Authors: McDonald Patricia P , Almond Richard E , Mapes James P , Friedman Stephen B 
Published: February 2020

Abstract
Polynuclear aromatic hydrocarbons (PAHs) are chemicals of concern when they contaminate the environment. Current detection methods (gas chromatography and liquid chromatography) are laborious, time consuming, and expensive. As an alternative, we developed a competitive enzyme-linked immunosorbent assay kit that can be used on site for the detection of PAHs at 1 ppm in soil. The immunoassay kit includes all the components necessary to conduct the analysis in the field. The test consists of 3 major steps: (1) sample treatment; (2) immunoassay, in which the target compound is bound by a specific antibody followed by the development of an indicator color; and (3) interpretation of results. A sample that develops less color than the standard is interpreted as positive (soil sample contaminated with PAHs at ≥1 ppm). Validation studies demonstrated that the assay is sensitive and specific. The assay detects PAH contamination in soil at 1 ppm or greater and specifically detects the 3- and 4-ringed aromatics and most of the 5-and 6-ringed aromatics. PAH-free soil samples gave negative results in the assay at a confidence level of &gt;95%. Matrix effects, interperson, and interlot variations were minimal. The test requires &lt;25 min to complete. The test kit is field compatible and provides a cost effective method for screening soils at risk for PAH contamination.
Cold-Vapor Generation for Inductively Coupled Argon Plasma/Atomic Emission Spectrometric Analysis. Part 3. Mercury
Authors: Anderson Kim A , Isaacs Brandon , Tracy Mark , Möller Gregory 
Published: February 2020

Abstract
A method is presented for the determination of total mercury in environmental samples by inductively coupled argon plasma/atomic emission spectroscopy (ICP/AES) using cold-vapor generation. A 1.0 g or 10 mL test portion is digested 6–12 h in a 16 × 150 mm, 10 mL volumetric test tube at room temperature and is subsequently digested on a programmed heating block at 95°C with trace-metal grade nitric acid. The digested samples are next treated with potassium permanganate and heated between 70 and 95°C; thereafter, oxalic acid is added to reach the final endpoint. The mercury(II) is reduced by sodium borohydride in a simplified continuous manifold. A standard pneumatic nebulizer effects the gas–liquid separation of mercury. Mercury is quantitated by ICP/AES at 194.232 nm. The instrument detection limit for the method is 0.2 μg/L. Water samples are analyzed directly. The detection limit is below the current National Primary Drinking Water Standard Maximum Concentration Limit of 2 μg/L for mercury. For a 10:1 dilution of a nominal 1.0 g solid test portion, the detection limit is 2.0 μg/L. This concentration is also less than the regulatory limit of 200 μg/L for the U.S. Environmental Protection Agency’s Toxicity Characteristic Leaching Procedure. The quantitation is linear up to 300 μg/kg. The method demonstrated statistical control for samples of biological and environmental interest.