bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of Selenium in Marine Biological Tissues by Transverse Heated Electrothermal Atomic Absorption Spectrometry with Longitudinal Zeeman Background Correction and Automated Ultrasonic Slurry Sampling
Authors: Méndez Hortensia , Alava Fausto , Lavilla Isela , Bendicho Carlos 
Published: February 2020

Abstract
A fast, sensitive, and reliable method for determination of selenium in marine biological tissues by electrothermal atomic absorption spectrometry with slurry sampling was developed. Slurries were prepared from fresh and frozen seafood samples that were previously homogenized, dried, and ground; particle sizes &lt;100 μm were taken for analysis. A 3% (v/v) HNO3 solution containing 0.01% (v/v) Triton X-100 was used as slurry diluent. Slurries were mixed on an automated ultrasonic slurry sampler at 20% amplitude for 30 s just before an aliquot was injected into the furnace. The method was successfully validated against the following certified reference materials: NRCC CRM DORM-2 (Dogfish muscle); NRCC CRM TORT-2 (Lobster hepatopancreas); NRCC CRM DOLT-2 (Dogfish liver); and BCR CRM 278 (Mussel tissue), and was subsequently applied to determination of Se in 10 marine biological samples. The influences of the drying procedure (oven-, microwave-, and freeze-drying), matrix modifier amount, mass of solid material in cup, and pipetting sequence are discussed. The limit of determination of Se was 0.16 μg/g and the repeatability, estimated as between-batch precision, was in the range of 4–8%. Se contents in the samples ranged from 0.6 to 2.8 μg/g. The proposed method should be useful for fast assessment of the daily dietary intake of Se.
Use of a Ruthenium(III), Iron(II), and Nickel(II) Hexacyanometallate-Modified Graphite Electrode with Immobilized Oxalate Oxidase for the Determination of Urinary Oxalate
Authors: Milardović Stjepan , Grabarić Zorana , Rumenjak Vlatko , Blau Nenad , Milošević Dražen 
Published: February 2020

Abstract
This paper describes the performance of a biosensor with an Ru(III), Ni(II), and Fe(II) hexacyanometallate-modified graphite electrode and immobilized oxalate oxidase for the determination of urinary oxalate. The addition of ruthenium enhances the electrochemical reversibility and chemical stability of the electrocrystallized layer and improves the sensitivity of the biosensor. Hydrogen peroxide, produced by the enzyme-catalyzed oxidation of oxalate, was measured at −50 mV vs an Hg|Hg2Cl2|3M KCl electrode in a solution of pH 3.6 succinic buffer, 0.1M KCl, and 5.4mM ethylenediaminetetraacetic acid. The linear concentration range for the determination of oxalate was 0.18–280 μM. The recoveries of added oxalate (10–35 μM) from aqueous solution ranged from 99.5 to 101.7%, whereas from urine samples without oxalate (or with a concentration of oxalate below the detection limit) the recoveries of added oxalate ranged from 91.4 to 106.6%. The oxalate in 24 h urine samples, taken during their daily routine from 35 infants and children, was measured and found to range from 0.6 to 121.7 mg/L. There were no interferences from uric acid, acetylsalicylic acid, and urea in the concentration range investigated, but paracetamol and ascorbic acid did interfere. A good correlation (R2 = 0.9242) was found between values obtained for oxalate in real urine samples by 2 laboratories, with the proposed biosensor and ion chromatography, respectively.
Sampling Grain Shipments To Detect Genetically Modified Seed
Authors: Whitaker Thomas B , Freese Larry , Giesbrecht Francis G , Slate Andrew B 
Published: February 2020

Abstract
Using the binomial distribution, the effect of sample size on the variability among sample test results when sampling a lot with 1.0% genetically modified (GM) or biotech seed was evaluated. The coefficient of variation, cv, among 500-seed sample test results taken from a lot with truly 1.0% was computed to be 44.5%. Increasing sample size to 1000 seeds reduced the cv among sample test results to 31.5%. The effects of sample size and accept/reject limits on the buyer's risk (bad lots accepted) and the seller's risk (good lots rejected) was also evaluated assuming a tolerance of 1.0% GM seed. Increasing sample size decreases both the buyer's and seller's risks at the same time. Using an accept/reject limit below the regulatory tolerance decreases the buyer's risk, but increases the seller's risk. Using an accept/reject limit above the regulatory tolerance decreases the seller's risk but increases the buyer's risk.
Hydrocolloid Interferences in the Determination of Pectin by the Carbazole Method
Authors: Kyriakidis Nikolaos B , Psoma Evaggelia 
Published: February 2020

Abstract
In the colorimetric determination of pectin by the carbazole method, some of the interfering compounds have been identified but the possible interference of different hydrocolloids is not known. Several hydrocolloids are currently used in the preparation of imitation and adulterated orange juice for cloud stabilization. Hydrocolloids studied were gum arabic, carboxylmethyl cellulose, sodium alginate, carrageenan, guar gum, and xanthan. The effects of these hydrocolloids on the carbazole method for pectin determination was studied. Procedures are proposed for the correct use of the carbazole method for pectin determination in the presence of extraneous hydrocolloids.
Study of the Versatility of a Graphite Furnace Atomic Absorption Spectrometric Method for the Determination of Cadmium in the Environmental Field
Authors: Rucandio M Isabel , Petit-Domínguez M Dolores 
Published: February 2020

Abstract
Cadmium is a representative example of trace elements that are insidious and widespread health hazards. In contemporary environmental analysis, there is a clear trend toward its determination over a wide range of concentrations in complex matrixes. This paper describes a versatile method for the determination of Cd at various levels (0.1–500 μg/g) in several sample types, such as soils, sediments, coals, ashes, sewage sludges, animal tissues, and plants, by graphite furnace atomic absorption spectrometry with Zeeman background correction. The effect of the individual presence of about 50 elements, with an interference/analyte concentration ratio of up to 105, was tested; recoveries of Cd ranged from 93 to 106%. The influence of different media, such as HNO3, HCl, HF, H2SO4, HClO4, acetic acid, hydroxylammonium chloride, and ammonium acetate, in several concentrations, was also tested. From these studies it can be concluded that the analytical procedure is scarcely matrix dependent, and the results obtained for a wide diversity of reference materials are in good agreement with the certified values.
Wind Tunnel Simulation of Air Pollution Dispersion in a Street Canyon
Authors: Civiš Svatopluk , Střižík Michal , Jaňour Zbynk , Holpuch Jan , Zelinger Zdenk 
Published: February 2020

Abstract
Physical simulation was used to study pollution dispersion in a street canyon. The street canyon model was designed to study the effect of measuring flow and concentration fields. A method of CO2-laser photoacoustic spectrometry was applied for detection of trace concentration of gas pollution. The advantage of this method is its high sensitivity and broad dynamic range, permitting monitoring of concentrations from trace to saturation values. Application of this method enabled us to propose a simple model based on line permeation pollutant source, developed on the principle of concentration standards, to ensure high precision and homogeneity of the concentration flow. Spatial measurement of the concentration distribution inside the street canyon was performed on the model with reference velocity of 1.5 m/s.
Determination of Arsenic in Homeopathic Drugs by Bromide Volatilization-Inductively Coupled Plasma-Atomic Emission Spectrometry
Authors: Lopez-Molinero Angel , Villareal Anselmo , Velilla Cesar , Andía David , Castillo Juan R 
Published: February 2020

Abstract
Arsenic in homeopathic drugs was determined by coupling a volatile generation with inductively coupled plasma-atomic emission spectrometry. The method is based on the chemical vaporization of arsenic(III) with bromide ions in sulfuric acid media using a batch procedure and subsequent introduction of the gaseous analyte into the plasma torch. The main and interactive effects of the experimental variables affecting this method were evaluated by a 2-level full factorial design. In optimized conditions by Simplex, the method shows an absolute detection limit (3 s) of 0.28 μg for the injection of 200 μL sample. The precision (% relative standard deviation) of the determination was 4.2% at a level of 50 μg/mL As(III) (n = 5). The interference effect of various ions on the arsenic signal was evaluated.
Dry Rehydratable Film Method for Rapid Enumeration of Coliforms in Foods (3M™ Petrifilm™ Rapid Coliform Count Plate): Collaborative Study
Authors: Lindberg Kathryn G , Lindberg Kathryn G , Kinneberg Karen M , Lindberg Kathryn G ,   Collaborators:, Batterson D , Bobb R , Boleszczuk P , Brudvig S , Bryant D , Bryce J , Buckner K , Bulthaus M , DeJesus J , Ellis K , Finkenbiner D , Fleming S , Follni-Lieder E , Harper C , Ihrke P , Johnson K , King J , Langridge M , Maycock L , McAteer L , McCann T , Otten N , Robbins R , Sass A , Saunders L , Schop R , Strand S , Tebay D , VanWinkle J , Wolowski C 
Published: February 2020

Abstract
A rehydratable dry-film plating method for coliforms in foods, the 3M™ Petrifilm™ Rapid Coliform Count plate method, was compared with the U.S. Food and Drug Administration's Bacteriological Analytical Manual method for nondairy foods and the American Public Health Association's Standard Methods for the Examination of Dairy Products (SMEDP) method for dairy foods. Six food types, vanilla ice cream, cheddar cheese, fresh refrigerated uncooked pasta, wheat flour, prepared frozen macaroni and cheese, and frozen hash browns, were analyzed for coliforms by 11 collaborating laboratories. For each food product tested, the collaborators received 8 blind samples consisting of a control sample and 3 levels of inoculated sample, each in duplicate. The mean log counts for the methods were comparable. The repeatability and reproducibility variances of the Petrifilm Rapid Coliform Count method at 14 and 24 h were not significantly different from those of the standard methods.
Determination of Vitamin B12 in Milk Products and Selected Foods by Optical Biosensor Protein-Binding Assay: Method Comparison
Authors: Indyk Harvey E , Persson Bjorn S , Caselunghe Malin C B , Moberg Anna , Filonzi Enrico L , Woollard David C 
Published: February 2020

Abstract
Biomolecular interaction analysis was evaluated for the automated determination of vitamin B12 in a range of foods. The analytical technique was configured as a biosensor-based, nonlabeled inhibition protein-binding assay using nonintrinsic R-protein. Sample extraction conditions were optimized, and both ligand specificity and nonspecific binding considerations were evaluated. Performance parameters included a quantitation range of 0.08–2.40 ng/mL, recoveries of 89–106%, agreement against assigned reference values for 3 independent certified food reference materials, and a mean between-laboratory reproducibility relative standard deviation of 4.9%. The proposed method was compared with reference microbiological and radioisotope protein-binding methods for a range of food samples. A wide selection of milks, infant formulas, meats, and liver were evaluated for their vitamin B12 content. The influence of season was studied in herd milk, early lactation was followed for a single animal, and the cobalamin content of bovine, caprine, and ovine milks was compared.
Residues of Oxytetracycline and Its 4′-Epimer in Edible Tissues from Turkeys
Authors: Capolongo Francesca , Santi Annalisa , Tomasi Luciana , Anfossi Paola , Missagia Mauro , Montesissa Clara 
Published: February 2020

Abstract
Residues of oxytetracycline (OTC) in edible tissues (muscle, liver, and kidney) of 18 turkeys were determined after continuous administration of the drug for 3 days in drinking water at the maximum recommended concentration of 400 mg/L. The European Union (EU) maximum residue limits (MRLs) set for OTC are 100 μg/kg in muscle tissues, 300 μg/kg in liver, and 600 μg/kg in kidney, as the sum of the parent compound and its derivative 4′-epi-oxytetracycline (4-epi-OTC). Cleanup of tissue samples was performed by metal chelate affinity chromatography (MCAC), but the original technique was miniaturized by the adoption of a mini solid-phase extraction column, allowing reduction of solvents, time, and hazardous waste. OTC and its 4′-epimer were quantitated by an isocratic liquid chromatography elution with UV detection. After 1 day of withdrawal, OTC plus 4-epi-OTC residues were greater than MRL values in muscle and liver; 3 days after the end of treatment, all tissue residues were far lower than the MRL values. At the first day after the end of treatment, 4-epi-OTC was detected at very low concentrations only in muscle, in liver after 1 and 3 days of withdrawal, and in kidney at all sampling times. The withdrawal time was calculated according to EU recommendations and was set at 5 days.
Comparison of Assurance Gold Salmonella EIA, BAX for Screening/Salmonella, and GENE-TRAK Salmonella DLP Rapid Assays for Detection of Salmonella in Alfalfa Sprouts and Sprout Irrigation Water
Authors: Stewart Diana S , Reineke Karl F , Tortorello Mary L 
Published: February 2020

Abstract
The Assurance Gold Salmonella EIA, BAX for Screening/Salmonella, and GENE-TRAK Salmonella DLP rapid assays were compared with official cultural methods described in the Bacteriological Analytical Manual (BAM) for analysis of alfalfa sprouts and sprout irrigation water for the presence of Salmonella. The lower limits of detection of 4 serovars of Salmonella cells (S. tennessee, S. muenchen, S. mbandanka, and S. cubana) in pure culture were determined as approximately log10 2, 5, and 6 for the BAX, GENE-TRAK, and Gold EIA, respectively. Despite its low detection limit, the BAX did not perform as well as the other assays in analyzing contaminated sprouts and sprout irrigation water. For 4 different lots of sprouts and sprout irrigation water samples inoculated with the 4 serovars at low [1-2 colony forming units (CFU/g)] and high (68–180 CFU/g) levels, the BAX detected Salmonella in 58/64 (90.6%) of the samples, compared with 64/64 (100%) by the GENE-TRAK, Gold EIA, and BAM methods. Assay performance was also compared for analysis of naturally contaminated sprouts and sprout irrigation water with 3 lots of alfalfa sprouted seeds associated with different salmonellosis outbreaks. Positive assay results for the naturally contaminated samples were Gold EIA 41, GENE-TRAK 36, BAM 33, and BAX 13.
Determination of Total Dietary Fiber in Selected Foods Containing Resistant Maltodextrin by Enzymatic-Gravimetric Method and Liquid Chromatography: Collaborative Study
Authors: Gordon Dennis T , Okuma Kazuhiro ,   Collaborators:, DeVries J W , Fukuhara K , Jacob W , Kuriyama N , Li B W , Matsuda I , McMonagle K , Parr G D , Porter S , Strong S , Sugimoto T , Tsuji K , Wolf B 
Published: February 2020

Abstract
A method was developed for determination of total dietary fiber (TDF) in foods containing resistant maltodextrin (RMD) which includes nondigestible carbohydrates that are not fully recovered as dietary fiber by conventional TDF methods such as AOAC 985.29 or 991.43. Because the average molecular weight (MW) of RMD is 2000 daltons, lower MW soluble dietary fiber components do not precipitate in 78% ethanol; therefore, RMD is not completely quantitated as dietary fiber by current AOAC methods. The accuracy and precision of the method was evaluated through an AOAC collaborative study. Ten laboratories participated and assayed 12 test portions (6 blind duplicates) containing RMD. The 6 test pairs ranged from 1.5 to 100% RMD. The method consisted of the following steps: (1) The insoluble dietary fiber (IDF) and high MW soluble dietary fiber (HMWSDF) were determined by AOAC 985.29. (2) Ion exchange resins were used to remove salts and proteins contained in the AOAC 985.29 filtrates (including ethanol and acetone). (3) The amount of low MWRMD (LMWRMD) in the filtrates were determined by liquid chromatography. (4) The TDF was calculated by summation of the IDF, HMWSDF, and LMWRMD fractions having nondigestible carbohydrates with a degree of polymerization of 3 and higher. Repeatability standard deviations (RSDr) were 1.33–7.46%, calculated by including outliers, and 1.33–6.10%, calculated by not including outliers. Reproducibility standard deviations (RSDR) were 2.48–9.39%, calculated by including outliers, and 1.79–9.39%, calculated by not including outliers. This method is recommended for adoption as Official First Action.
Determination of the Total Nitrogen Content of Hard, Semihard, and Processed Cheese by the Kjeldahl Method: Collaborative Study
Authors: Lynch Joanna M , Barbano David M , Fleming J Richard ,   Collaborators:,   Barbano Laboratory,   California Department of Food and Agriculture,   Dairy One,   Dairy Quality Control Institute, Inc,   Land O’Lakes,   State of Wisconsin Department of Agriculture,   U.S. Department of Agriculture (USDA) Atlanta Milk Market Administrator Laboratory,   USDA Boston Milk Market Administrator Laboratory,   USDA Chicago Milk Market Administrator Laboratory,   USDA Cleveland Milk Market Administrator Laboratory,   USDA Dallas Milk Market Administrator Laboratory,   USDA Kansas City Milk Market Administrator Laboratory,   USDA Louisville Milk Market Administrator Laboratory,   USDA Seattle Milk Market Administrator Laboratory,   USDA Tulsa Milk Market Administrator Laboratory
Published: February 2020

Abstract
The objective of this collaborative study was to determine interlaboratory performance statistics for a modified and optimized version of AOAC Method 920.123 for the determination of the total nitrogen content of hard, semihard, and processed cheese by Kjeldahl analysis. Details included addressing the issues of material homogeneity, test portion size (1 g), quantitative transfer (weighing on to filter paper), ensuring system suitability (nitrogen recoveries), and using AOAC Method 991.20 as the basis for nitrogen analysis. Fifteen laboratories tested 18 pairs of blind duplicate cheese materials with a crude protein content between 18 and 36%. Materials represented hard, semihard, and processed commercial cheeses with a wide range of composition. Statistical performance parameters expressed as crude protein (nitrogen × 6.38), g/100 g, with invalid and outlier data removed were mean = 26.461, repeatability standard deviation (Sr) = 0.111, reproducibility standard deviation (SR) = 0.153, repeatability relative standard deviation (RSDr) = 0.42%, reproducibility relative standard deviation (RSDR) = 0.58%, repeatability (r) = 0.312, and reproducibility (R) = 0.428. The interlaboratory study results were acceptable and comparable to those for the milk Kjeldahl nitrogen method on a relative nitrogen basis. The Study Directors recommend that this modified method for the determination of total nitrogen in hard, semihard, and processed cheese by Kjeldahl analysis be adopted First Action as an improved method to replace Method 920.123.
Analysis of Grass Silage from Northwestern Spain by Near-Infrared Reflectance Spectroscopy
Authors: Villamarín Begoña , Fernández Esperanza , Mendéz Jesus 
Published: February 2020

Abstract
Near-infrared reflectance spectroscopy (NIRS) was evaluated for the determination of protein, crude fiber (CF), acid detergent fiber (ADF), and neutral detergent fiber (NDF) in grass silage. Calibration equations were based on analyses of 366 samples of grass silage produced in Northwestern Spain over 4 consecutive years (1992–1995) and validated by analyses of a set of 72 silage samples harvested during 1996. Dried and ground samples were analyzed by chemical and NIRS procedures. The spectral data were analyzed by regression against a range of chemical parameters, using modified partial least-squares (MPLS) multivariate analysis in conjunction with different mathematical treatments of the spectra. For each parameter, the optimum calibration was evaluated on the basis of the coefficient of multiple determination (R2), the coefficient of simple correlation (r2), the standard error of calibration (SEC), the standard error of cross-validation (SECV), and the standard error of validation (SEV). R2 and r2 were &gt;0.90; SEC values were 0.58, 1.04, 1.40, and 1.75; SECV values were 0.64, 1.15, 1.50, and 2.04; and SEV values were 0.56, 1.02, 1.42, and 1.80 for protein, CF, ADF, and NDF, respectively. The ratio of the standard deviation of the reference data to the SEV was &gt;3.0 for each of the 4 parameters, which indicates that the equations can be used in routine analysis.
Determination of Mercury in Seafood by Flow Injection–Cold Vapor Atomic Absorption Spectrometry after Microwave Digestion: NMKL Interlaboratory Study
Authors: Julshamn Kaare , Brenna Jan ,   Collaborators:, Åsman B , Ekman A , El-Ghauoui A , Gjerstad K-O , Grønningen D , Hammer S H , Jensen A M , Liukkonen-Lilja H , Mikkola J , Ruth T , Sedal L O , Solli B , Venalainen E-R , Wollertsen N 
Published: February 2020

Abstract
Ten laboratories participated in an interlaboratory method-performance (collaborative) study of a method for the determination of mercury in foods of marine origin by flow injection–cold vapor atomic absorption spectrometry after wet digestion using a microwave oven technique. The study was preceded by a training round of samples of known identity. The method was tested on a total of 7 seafood products: blue mussel (Mytilus edulis), cod muscle (Gadus morhua), crab (Cancer pagurus), scampi (Nephrops norwegicus), black scabbard fish (Aphnopus carbo), longnose velvet dogfish (Centroscymus crepidater), and Portuguese dogfish (Cenbroscymus coelolepis) with mercury concentrations of 0.14, 0.24, 0.35, 0.59, 1.42, 4.2, and 13.2 μg/g, respectively. The materials were presented to the participants in the study as blind duplicates, and the participants were asked to perform single determinations on each sample. Repeatability relative standard deviations (RSDr) for mercury ranged from 2.4 to 14.0%. Reproducibility relative standard deviations (RSDR) ranged from 7.7 to 16.6%. HORRAT values for all samples were &lt;1.0.
Isolation of Light Filth from Ground Oregano and Ground Marjoram: A Modification Using Isopropanol as a Defatting Agent: In-House Study
Authors: Wheeler Mark Wheeler , Bennett Barbara , Marks Harry 
Published: February 2020

Abstract
A procedural modification of the AOAC Official Method for extracting light filth from ground oregano and ground marjoram was tested in an intralaboratory study. The modified method specifies isopropanol defatting, 975.49A(a), rather than chloroform–isopropanol defatting, 975.49A(b), followed by direct flotation as directed in AOAC Official Method, 975.49B(b). The modified method provided comparable results in less time while also providing safety, health, and financial benefits.
Determination of Vitamin K1 Isomers in Foods by Liquid Chromatography with C30 Bonded-Phase Column
Authors: Woollard David C , Indyk Harvey E , Fong Bertram Y , Cook Kathleen K 
Published: February 2020

Abstract
Vitamin K1 was determined in a variety of foods by using reversed-phase liquid chromatography with a C30 column followed by post-column reduction to the fluorescent hydroquinone derivatives. Lipids were removed by lipase digestion, followed by single extraction into hydrocarbon, and the protocol was extended to selected natural and processed foods. Biologically active trans- and inactive cis-vitamin K1 isomers were measured individually to evaluate the true nutritional status of the products. Method performance parameters confirmed the validity of the technique. The use of the triacontylbonded C30 phase for selective phylloquinone isomer measurement extends previously validated AOAC Method 999.15 for vitamin K1 in milk and infant formula to a wider range of foods important in the human diet. The cis-vitamin K1 isomer contributes up to about 15% of total phylloquinone in certain foods.