bluuebunny/crossref_metadata_2025_split huggingface dataset:
Relationship of (Known) Control Values to (Unknown) Test Values in Proficiency Studies of Pesticide Residues
Authors: Horwitz William , Wood Roger 
Published: February 2020

Abstract
Proficiency studies have been suggested as an alternative source of information for evaluating method performance characteristics when results from interlaboratory method performance studies conforming to internationally recognized protocols are not available. To explore this possibility, results were examined from ongoing proficiency studies of pesticide residue analyses in celery, carrot, and grape purees, and in wine. Statistical performance parameters were calculated from 18 data sets analyzed as unknowns by about 60 analysts for 12 analytes in the 25–1000 μg/kg range, and from presumably parallel control (spike) analyses conducted by about half of the participants. A surprising finding was that recovery of known, independent control additions by the participant did not correlate with the recoveries determined as unknowns in the exercise. The data suggest that censoring or truncating of control data has occurred. The question of substitution of proficiency data for method performance data cannot be answered until the problem of unbiased reporting of control data is resolved.
Determination of Histamine in Tomatoes by Liquid Chromatography/Mass Spectrometry
Authors: Bolygo Elek , Cooper Paul A , Jessop K Michael , Moffatt Frank 
Published: February 2020

Abstract
The histamine level in tomato fruits and pastes was determined by 2 orthogonal techniques as a means of comparing accuracy. Close statistical agreement was found between assays for free histamine by capillary electrophoresis (with UV absorbance detection), and for the dansyl derivative by reversed-phase liquid chromatography (LC). Both techniques have adequate sensitivity for the analysis of endogenous histamine in tomatoes, but LC/electrospray tandem mass spectrometry was more sensitive by at least an order of magnitude, down to a level of 0.05 mg/kg.
Determination of Polydextrose as Dietary Fiber in Foods
Authors: Craig Stuart A S , Holden James F , Khaled Maha Y 
Published: February 2020

Abstract
Polydextrose (Litesse®) provides physiological effects consistent with dietary fiber. However, AOAC methods for measuring total dietary fiber (TDF) in foods include an ethanol precipitation step in which polydextrose and similar carbohydrates are discarded and therefore not quantitated. This study describes a method developed to quantitate polydextrose in foods. The new method includes water extraction, centrifugal ultrafiltration, multienzyme hydrolysis, and anion exchange chromatography with electrochemical detection. Six foods were prepared with 4 levels of polydextrose to test the ruggedness of the method. Internal validation demonstrated the ruggedness of the method with recoveries ranging from 83 to 104% with an average of 95% (n = 24) and relative standard deviation of recoveries ranging from 0.7 to 13% with an average of 3.3% (n = 24). The value is added to that obtained for dietary fiber content of foods using the AOAC methods, to determine the TDF content of the food.
Determination of Ginsenosides in Panax ginseng Roots by Liquid Chromatography with Evaporative Light-Scattering Detection
Authors: Fuzzati Nicola , Gabetta Bruno , Jayakar Kaishik , Pace Roberto , Ramaschi Giuseppe , Villa Francesco 
Published: February 2020

Abstract
A liquid chromatographic method was developed and validated for the determination of ginsenosides in Panax ginseng roots by using evaporative light-scattering detection. Eighteen ginsenosides were separated on a reversed-phase C18 column with water–ammonium acetate–acetonitrile as the mobile phase. The method is suitable for the routine determination of ginsenosides in P. ginseng roots and extracts. The validation of the method was comprehensive for efficiency and recovery optimization of the P. ginseng roots extraction, specificity by liquid chromatography/mass spectrometry, linearity, stability, reproducibility, repeatability, intermediate precision, and robustness.
Molecular Detection of Burkholderia cepacia in Toiletry, Cosmetic, and Pharmaceutical Raw Materials and Finished Products
Authors: Jimenez Luis , Smalls Stacey 
Published: February 2020

Abstract
A polymerase chain reaction (PCR) assay was developed and compared with standard methods for rapid detection of Burkholderia cepacia, a major industrial contaminant, in cosmetic and pharmaceutical raw materials and finished products. Artificially contaminated samples were incubated for 24 h in trypticase soy broth containing 4% Tween 20 and 0.5% soy lecithin. DNA was extracted from each sample using a proteinase K-tris-EDTA-Tween 20 treatment at 35°C. The extracted DNA was added to Ready-To-Go PCR beads and specific DNA primers for B. cepacia. The B. cepacia DNA primers coded for a 209-base pair (bp) fragment of the 16S rRNA ribosomal gene. No DNA amplification was observed in samples that were not spiked with B. cepacia. However, all contaminated samples showed the specific 209-bp fragment for B. cepacia. There was a 100% correlation between standard methods and the PCR assay. Standard microbiological methods required 5–6 days for isolation and identification of spiked microorganisms, whereas PCR detection and identification was completed in 27 h. PCR detection of B. cepacia allows for rapid quality evaluation of cosmetic and pharmaceutical raw materials and finished products.
Graphite Furnace Atomic Absorption Spectrometric Determination of Lead and Cadmium Extracted from Ceramic Foodware: Collaborative Study
Authors: Hight Susan C ,   Collaborators:, Ayyad N , Barnes B , Brown J , DePalma B , Gambaro M , Motley E , Shippey K 
Published: February 2020

Abstract
A modification of the official flame atomic absorption spectrometric (FAAS) method for determining lead and cadmium extracted from ceramic foodware was collaboratively studied. In the modified method, graphite furnace atomic absorption spectrometry (GFAAS) is substituted for FAAS. The modified method also includes mandatory quality control procedures to improve method performance. The extraction procedure of the official method (leaching with 4% acetic acid for 24 h at room temperature) remains unchanged. Seven laboratories analyzed blind duplicate portions of 3 ceramicware leach solutions containing Pb at concentrations of 0.0196, 0.403, and 3.73 μg/mL and Cd at concentrations of 0.00236, 0.0456, and 0.544 μg/mL. Performance of the modified method compared well with that of the official method. The repeatability relative standard deviation (RSDr) ranged from 0.87 to 6.7% for Pb and from 3.7 to 11% for Cd. The reproducibility relative standard deviation (RSDR) ranged from 4.5 to 12% for Pb and from 7.0 to 11% for Cd. Accuracy of collaborator results was 97–98% for Pb and 93–101% for Cd. Quality control results and quantitation limits were excellent. Method quantitation limits varied among laboratories from 0.005 to 0.019 μg/mL for Pb and from 0.0004 to 0.0019 μg/mL for Cd. The modified method was adopted First Action by AOAC INTERNATIONAL.
Determination of Metals in Foods by Atomic Absorption Spectrometry after Dry Ashing: NMKL1 Collaborative Study
Authors: Jorhem Lars ,   Collaborators:, Afthan G , Cumont G , Dypdahl H P , Gadd K , Havre G N , Julshamn K , Kåverud K , Lind B , Loimaranta J , Merseburg M , Olsson A , Piepponen S , Sundström B , Uppstad B J , Waaler T , Winnerstam L 
Published: February 2020

Abstract
A method for determination of lead, cadmium, zinc, copper, and iron in foods by atomic absorption spectrometry (AAS) after dry ashing at 450°C was collaboratively studied in 16 laboratories. The study was preceded by a practice round of familiarization samples and another round in which solutions were distributed and the metals were determined directly by AAS. The study included 5 different foods (liver paste, apple sauce, minced fish, wheat bran, and milk powder) and 2 simulated diets. A single analysis was carried out with each sample. Suitable sample combinations were used as split-level combinations for determination of the repeatability standard deviation. The reproducibility relative standard deviation for each of the elements ranged from 20 to 50% for lead concentrations of 0.040–0.25 mg/kg, from 12 to 352% for cadmium concentrations of 0.001–0.51 mg/kg, from 4 to 8% for zinc concentrations of 0.7–38 mg/kg, from 7 to 45% for copper concentrations of 0.51–45 mg /kg, and from 11 to 14% for iron concentrations of 4–216 mg/kg.
Microwave-Assisted Extraction and Accelerated Solvent Extraction with Ethyl Acetate–Cyclohexane before Determination of Organochlorines in Fish Tissue by Gas Chromatography with Electron-Capture Detection
Authors: Weichbrodt Marion , Vetter Walter , Luckas Bernd 
Published: February 2020

Abstract
Focused open-vessel microwave-assisted extraction (FOV–MAE), closed-vessel microwave-assisted extraction (CV–MAE), and accelerated solvent extraction (ASE) were used for extraction before determination of organochlorine compounds (polychlorinated biphenyls, DDT, toxaphene, chlordane, hexachlorobenzene, hexachlorocyclohexanes, and dieldrin) in cod liver and fish fillets. Wet samples were extracted without the time-consuming step of lyophilization or other sample-drying procedures. Extractions were performed with the solvent mixture ethyl acetate–cyclohexane (1 + 1, v/v), which allowed direct use of gel-permeation chromatography without solvent exchange. For FOV–MAE, the solvent mixture removed water from the sample matrix via azeotropic distillation. The status of water removal was controlled during extraction by measuring the temperature of the distillate. After water removal, the temperature of the distillate increased and the solvent mixture became less polar. Only the pure extraction solvent allowed quantitative extraction of the organochlorine compounds. For CV–MAE, water could not be separated during the extraction. For this reason, the extraction procedure for wet fish tissue required 2 extraction steps: the first for manual removal of coextracted water, and the second for quantitative extraction of the organochlorine compounds with the pure solvent. Therefore, CV–MAE is less convenient for samples with high water content. For ASE, water in the sample was bound with Na2SO4. The reproducibility for each technique was very good (relative standard deviation was typically &lt;10%); the slightly varying levels were attributed to deviations during sample cleanup and the generally low levels.
Identification of Derivatives of Bisphenol A Diglycidyl Ether and Novolac Glycidyl Ether in Can Coatings by Liquid Chromatography/Ion Trap Mass Spectrometry
Authors: Berger Urs , Oehme Michael 
Published: February 2020

Abstract
A reversed-phase liquid chromatographic method combined with fluorescence and multiple mass spectrometric detection in series is presented for the separation and structure elucidation of bisphenol A diglycidyl ether (BADGE) and novolac glycidyl ether (NOGE) derivatives. Atmospheric pressure chemical ionization in the positive ion mode and collision induced fragmentation in the ion trap allowed identification of BADGE- and NOGE-related compounds originating from reactions of the glycidyl ethers with bisphenols, solvents, and chain stoppers. Two extracts from food-can coatings were investigated in detail. It was possible to elucidate the structures of many substances and consequently to draw conclusions about the production of the lacquers.
Simultaneous Determination of Ascorbic Acid and Acetylsalicylic Acid in Pharmaceutical Formulations
Authors: Toral M Ines , Lara Nelson , Richter Pablo , Tassara Andres , Tapia A E , Rodriguez Claudio 
Published: February 2020

Abstract
A direct, simple, and practical first-derivative spectrophotometric method is described for simultaneous determination of ascorbic acid and acetylsalicylic acid. The effects of the solvent, excipients, and spectral variables on the analytical signal were investigated. The drugs were determined simultaneously with a 0.01M methanolic hydrochloric acid solution as the solvent, and the signals were evaluated directly by using the zero-crossing method at 245.0 and 256.0 nm for acetylsalicylic acid and ascorbic acid, respectively. The method allows the simultaneous determinations of acetylsalicylic acid and ascorbic acid in the ranges of 6.6 × 10−6 to 1.5 × 10−4M and 3.4 × 10−6 to 2.0 × 10−4M, respectively, with standard deviation of &lt;2.0%. The proposed method was applied to determinations of these drugs in tablets.
Determination of Locust Bean Gum and Guar Gum by Polymerase Chain Reaction and Restriction Fragment Length Polymorphism Analysis
Authors: Meyer Kerstin , Rosa Christelle , Hischenhuber Claudia , Meyer Rolf 
Published: February 2020

Abstract
A polymerase chain reaction (PCR) was developed to differentiate the thickening agents locust bean gum (LBG) and the cheaper guar gum in finished food products. Universal primers for amplification of the intergenic spacer region between trnL 3’ (UAA) exon and trnF (GAA) gene in the chloroplast (cp) genome and subsequent restriction analysis were applied to differentiate guar gum and LBG. The presence of &lt;5% (w/w) guar gum powder added to LBG powder was detectable. Based on data obtained from sequencing this intergenic spacer region, a second PCR method for the specific detection of guar gum DNA was also developed. This assay detected guar gum powder in LBG in amounts as low as 1% (w/w). Both methods successfully detected guar gum and/or LBG in ice cream stabilizers and in foodstuffs, such as dairy products, ice cream, dry seasoning mixes, a finished roasting sauce, and a fruit jelly product, but not in products with highly degraded DNA, such as tomato ketchup and sterilized chocolate cream. Both methods detected guar gum and LBG in ice cream and fresh cheese at levels &lt;0.1%.
Rapid Methods To Enumerate Escherichia coli in Foods Using 4-Methylumbelliferyl-ß-D-Glucuronide
Authors: Ekholm Diane F , Hirshfield Irvin N 
Published: February 2020

Abstract
Three methods to enumerate Escherichia coli in food were compared. They were based on AOAC methods using lauryl tryptose broth (LST) medium, LST-4-methylumbelliferyl-ß-D-glucuronide (MUG) medium, and a proposed method using regular LST in combination with E. coli (EC)–MUG medium. An efficacious and cost-effective method is needed that can detect E. Coli and does not produce false presumptive positives. We tested 170 cheeses, 40 frozen processed seafood samples, 210 tree nuts, and 40 other samples. The method of choice for enumerating E. Coli depends on the commodity itself. For a product, such as hard cheese or processed seafood, with a history of being negative for E. Coli and other lactose-fermenting organisms, the proposed method using regular LST/EC–MUG is a good choice. These samples were seldom presumptive positive in the primary LST medium. If gas was produced, EC–MUG was an effective secondary medium. No false positives (fluorescence) or negatives were detected in EC–MUG medium. For a product with a history of being positive for E. Coli and/or other lactose fermenting organisms, such as tree nutmeats or cheeses that are ripened by bacteria or mold, the method using LST–MUG is the method of choice. A presumptive positive in the LST–MUG medium was highly correlative with the biochemical tests that confirmed a sample contain E. Coli. For samples spiked with E. Coli, the results from each of these 3 methods were identical, and were consistent in enumerating E. Coli.
Isoflavone Glycosides from the Root Wood of Erythrina latissima
Authors: Wanjala Cornelius C W , Majinda Runner R T 
Published: February 2020

Abstract
The molecular structures of 3 isoflavone glycosides isolated from the root wood of Erythrina latissimawere established as 4′-hydroxyisoflavone-7-O-β-D-glucopyranoside (compound 1); 4′-hydroxyisoflavone-7-O-α-L-rhamnosyl (1→6)-β-D-glucopyranoside (compound 2); and a new compound 4′, 8-dimethoxy isoflavone-7-O-α-L-rhamnosyl(1→6)-β-D-glucopyranoside (8-O-methylretusin-7-O-α-L-rhamnosyl (1→6)-β-D-glucopyranoside) (compound 3).
Liquid Chromatographic Determination of Methyl Anthranilate in Artificially Flavored Nonalcoholic Beverages
Authors: Thompson Richard D , Quaife John T 
Published: February 2020

Abstract
A liquid chromatographic method was developed that provides a simple and rapid means of determining methyl anthranilate (MA) in carbonated and noncarbonated, artificial grape-flavored, nonalcoholic beverages. The proposed procedure, which was applied to 12 different products, uses a Nova-Pak C18 column, a mobile phase containing acetonitrile–0.025M KH2PO4 (40 + 60), pH 3.00, and UV detection at 220 nm. Assay values ranged from 0.35 to 16.6 Μg MA/mL. The intralaboratory precision (relative standard deviation) for the products ranged from 0.51 to 2.23% (n = 5), and recoveries via fortification ranged from 83.6 to 102.4%. The limits of quantitation and detection were 0.00417 and 0.00125 μg/mL, respectively, and the analyte response was linear over a 100-fold concentration range (0.0001–0.01 mg/mL).
LC/MS Confirmation of Ionophores in Animal Feeds
Authors: Turnipseed Sherri B , Roybal José E , Pfenning Allen P , Gonzales Steve A , Hurlbut Jeffrey A , Madson Mark R 
Published: February 2020

Abstract
A liquid chromatographic/mass spectrometric (LC/MS) electrospray confirmation method has been developed to confirm 4 ionophores (monensin, lasalocid, salinomycin, and narasin) in a variety of animal feeds using a single quadrupole mass spectrometer. The sodium ions of these compounds are dominant in the electrospray mass spectrum. Using optimized “in-source” collision induced dissociation, characteristic fragment ions seen previously using MS/MS can be observed. The drugs were extracted from the feed matrix using hexane–ethyl acetate and isolated using a silica solid-phase extraction cartridge. These ionophores were confirmed in both medicated feeds and nonmedicated feeds fortified with these drugs at the 1–50 ppm level. In addition, this method was used to confirm residues of monensin in a nonmedicated feed that was collected from a feed mill immediately after the production of a similar feed that was medicated with high levels of monensin.
Molecular Diagnosis of Microbial Contamination in Cosmetic and Pharmaceutical Products: A Review
Authors: Jimenez Luis 
Published: February 2020

Abstract
Molecular methodologies such as adenosine triphosphate (ATP) bioluminescence and polymerase chain reaction (PCR)-based assays provide rapid quality control analysis of cosmetic and pharmaceutical finished products and raw materials. Using a single enrichment broth for bacteria, yeast, and mold, ATP bioluminescence detected microbial contamination within 27 h. Samples were automatically lysed to release microbial ATP and light production was quantitated using the Celsis Optocomp. However, to maintain the detection time to within 27 h, different enrichment broths were required for neutralization of antimicrobial ingredients in finished products and to provide specific nutrients for growth optimization. To perform the PCR reaction, bacterial DNA was extracted using a Tris-EDTA–Tween 20–proteinase K buffer at 35°C while yeast and mold DNA were extracted using a Tris-EDTA–SDS buffer at 95°C. Extracted microbial DNA was added to Ready-To-Go PCR™ beads and specific DNA primers. The primers were targeted to amplify specific regions within Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhimurium, Burkholderia cepacia, Candida albicans, and Aspergillus niger. Furthermore, conserved bacterial ribosomal DNA sequences have also been used for sterility testing of samples. The results from these studies indicate that both ATP bioluminescence and PCR assays provide rapid, reliable, and cost effective methods for quality evaluation. This will ultimately result in faster product release and production optimization.
Comparison of the Reveal 20-Hour Method and the BAM Culture Method for the Detection of Escherichia coli O157:H7 in Selected Foods and Environmental Swabs: Collaborative Study
Authors: Bird Charles B , Hoerner Rebecca J , Restaino Lawrence ,   Collaborators:, Anderson G , Birbari W , Bodra L , Brookman D , Bryant D , Campbell C , Degraft-Hanson J , Fetviet D , Forde R , Goins D , Hajkowski S , Haley E , Holland R , Jones J , Joseph J M , Kallewaard N , Keckeissen J , Kirkbride T , Kusch S , Noel D , Nutsch A , Okolo C , Parks K , Raines D , Remes A , Roach V , Robbins R , Rodrick G , Shelef L , Theissen H , Vasavada P C , Wang T 
Published: February 2020

Abstract
Four different food types along with environmental swabs were analyzed by the Reveal for E. coli O157:H7 test (Reveal) and the Bacteriological Analytical Manual (BAM) culture method for the presence of Escherichia coli O157:H7. Twenty-seven laboratories representing academia and private industry in the United States and Canada participated. Sample types were inoculated with E. coli O157:H7 at 2 different levels. Of the 1095 samples and controls analyzed and confirmed, 459 were positive and 557 were negative by both methods. No statistical differences (p &lt;0.05) were observed between the Reveal and BAM methods.
Determination of Manganese in Feedstuffs by Flow Injection Spectrophotometry Based on Rapid Formation of Permanganate at Room Temperature
Authors: Liu Jing-Fu , Feng Ying-Di , Jiang Gui-Bin 
Published: February 2020

Abstract
A simple and rapid flow injection spectrophotometric procedure was developed for determination of manganese. In the presence of pyrophosphate and acetate, manganese was immediately oxidized to permanganate by periodate at room temperature in slightly alkaline medium. Under optimized conditions, the determination was made with a sampling rate of 120/h, a linear range of 0–30 mg/L Mn(II), a detection limit (S/N = 3) of 0.08 mg/L, and a relative standard deviation of 0.6% (n = 11) at 10 mg/L Mn(II). The proposed method was used to determine manganese in trace mineral premixes and feedstuffs. Results agreed well with those obtained by the standard atomic absorption spectroscopy method.
Simultaneous Determination of Magnesium L-Ascorbyl-2-Phosphate and Kojic Acid in Cosmetic Bleaching Products by Using a Microbore Column and Ion-Pair Liquid Chromatography
Authors: Shih Ying 
Published: February 2020

Abstract
A rapid, sensitive, and reliable method was developed for the simultaneous determination of magnesium L-ascorbyl-2-phosphate (AS-PM) and kojic acid (KA), commonly using bleaching agents in cosmetic products. The method uses a prepacked C18 microbore column for ion-pair liquid chromatography with photodiode array detection. The eluant is 0.5mM tetrabutylammonium bromide and 0.05M phosphate buffer, pH 5, containing 5% methanol, at a flow rate of 70 μL/min. The determinations of AS-PM and KA were linear in the range of 0.5–1000 and 0.25–500 ng, respectively.The precision of the assay ranged from 0.31 to 2.19%, and the detection limits (signal-to-noise ratio = 3) were 0.04 and 0.02 ng for AS-PM and KA, respectively.