bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of Calcium by Inductively Coupled Plasma-Atomic Emission Spectrometry, and Lead by Graphite Furnace Atomic Absorption Spectrometry, in Calcium Supplements after Microwave Dissolution or Dry-Ash Digestion: Method Trial
Authors: Siitonen Paul H , Thompson Harold C ,   Method Trial Participants: Anjum S. Choudhry, FDA, Atlanta Center for Nutrient Analysis, Atlanta, GA; Ronald W. Marts, FDA, Kansas City District Office, Lenexa, KS; and Paul H. Siitonen, FDA, National Center for Toxicological Research, Jefferson, AR
Published: February 2020

Abstract
A 3-laboratory method trial was conducted to evaluate 2 sample digestion procedures and instrumental determination parameters for analysis of calcium and lead in Ca supplements. Calcium supplements were treated by dry-ash digestion or microwave dissolution prior to spectrometric analysis. In each case, Pb was determined by graphite furnace atomic absorption spectrometry and Ca by inductively coupled plasma-atomic emission spectrometry. Blind duplicates of 6 Ca supplement samples were analyzed after each sample treatment procedure. Matrix pairs contained dissimilar Pb levels to cover the analyte range encountered during method development. Calcium content of the Ca supplement samples also reflected the range seen during method development. Stock solutions of Ca and Pb were supplied to collaborators for preparation of quantitation standards to remove a variable external to the method. National Institute of Standards and Technology Standard Reference Material (NIST SRM) 1486, bone meal, was included to assess method accuracy and recovery at NIST certificate Ca and Pb levels for this material (26.58 ± 0.24% Ca and 1.335 ± 0.014 µg Pb/g). Analyses of the NIST SRM yielded 25.9 ± 1.1 and 27.2 ± 2.3% Ca and 1.53 ± 0.19 and 1.26 ± 0.19 µg Pb/g for dryash and microwave procedures, respectively. Statistical analyses of data indicated acceptable repeatability and reproducibility for determination of Pb and Ca in various Ca supplements. With either sample preparation technique, the method Received August 27, 1997. Accepted by JS July 2,1998. is appropriate for determining Pb or Ca in Ca supplements.
Identification and Semiquantitative Estimation of Antibiotics Added to Complete Feeds, Premixes, and Concentrates
Authors: Gafner Jean-Louis 
Published: February 2020

Abstract
Classical microbiological methods for determining antimicrobial compounds in feeds are nonspecific. Thus, there is a need to identify biological activity, and bioautography is used for thispurpose. A routine method for detecting the following antimicrobial sub stances in feeds is described: avilamycin, avoparcin, Zn-bacitracin, erythromycin, flavomycin, furazolidone, lasalocid, monensin, narasin, penicillin, salinomycin, spiramycin, tetracyclines, tylosin, and virginiamycin. Carbadox can be detected by UV light examination of the plates prior to bioautography. Semiquantitative estimations of antibiotic content are compared with quantitative determinations of the above mentioned sub stances in feeds, except erythromycin, penicillin, and tetracyclines. Detection limits range from 0.1 mg/kg (chlortetracycline) to 20 mg/kg (lasalocid). The method involves agar diffusion of buffered samples, a neutral extraction of polyether antibiotics followed bythin-layer chromatography (TLC), and an acid extraction for other antibiotics followed by TLC. Five test bacteria were used for the main detection by agar diffusion: Micrococcus luteusATCC 9341, Staphylococcus aureus ATCC 6538P, Corynebacterium xerosis NCTC 9755, Bacillus cereus ATCC 11778, and B. subtilis ATCC 6633. Identification after TLC was achieved by bioautography with the most sensitive microorganism(s). This method allows one laboratory technician to analyze up to 30 feed samples within 2.5 working days, provided that feeds of the same category are analyzed in the same run, and that labels of additives are available. Qualitative and semiquantitative information are valuable when performing a quantitative antibiotic determination and it provides proof that the activity determined is due to the tested substance. This last feature is essential from the perspective of quality assurance of results.
Dry Rehydratable Film Method for Enumerating Confirmed Escherichia coli in Poultry, Meats, and Seafood: Collaborative Study
Authors: Gangar Vidhya , Curiale Michael S , Lindberg Kathryn , Gambrel-Lenarz Sonya ,   Collaborators:, Adamson E , Barbari W , Brodsky M , Blackwell G , Bryce J , Cook P , Davis B , Deabel J , D’Onorio A , Follmi-Lieder E , Franklin J , Gambrel-Lenarz S , Horne S , James-Davis L , Lindgren S , McIntyre D , Moore J , Moorman M , Puccini M , Pulusani S , Sass A , Saunders L , Schop R , Sigua C A , Sinclair P , Story R , Westmoreland R , Windsor S , Witt J L 
Published: February 2020

Abstract
A rehydratable dry-film plating method for Escherichia coli, the Petrifilm E. coli/Coliform (EC) Count Plate in foods, has been compared with the AOAC INTERNATIONAL most probable number (MPN) method. Eleven laboratories participated in the collaborative study. Three E. coli levels in 8 samples each of frozen raw ground turkey, frozen raw ground beef, and frozen cooked fish were tested in duplicate. Mean log counts for the Petri film plate procedure were not significantly different from those for the MPN procedure for cooked fish samples inoculated with low or high inocula levels, for samples of raw turkey inoculated at medium level, and for beef inoculated at low, medium, and high levels. Repeatability and reproducibility vari ances of the Petrifilm EC Plate method recorded at 24 h were as good as or better than those of the MPN method. The dry rehydratable film method for enumerating confirmed E. coli in poultry, meats, and seafood has been adopted first action by AOAC INTERNATIONAL.
Spectrophotometric Determination of Some Hydrazine Derivatives Using 2,3-Dichloro-5,6-Dicyano-p-Benzoquinone
Authors: Al-Ghannam Sheikha Mohamed , El-Brashy Amina Mohamed , Al-Hussein Laila Abdel-Rahman 
Published: February 2020

Abstract
A simple, sensitive, and rapid spectrophotometric method for determining isoniazid, isocarboxazid, and iproniazid phosphate is described. In this method, 2,3-dichloro-5,6-dicyano-p-benzoquinone (a π-acceptor) is used to form charge-transfer complexes with cited drugs (n-donors). The procedure is sensitive enough to permit unit dose assay of the individual drugs in their pharmaceutical formulations. The assay results are in accord with the pharmacopoeial assay results.
Arsenic Determination in Certifiable Color Additives by Dry Ashing Followed by Hydride Generation Atomic Absorption Spectrometry
Authors: Hepp Nancy M 
Published: February 2020

Abstract
The preparations of digested samples of certifiable color additives by dry ashing and wet digestion for arsenic analysis by hydride generation atomic absorption spectrometry (AAS) were compared. The dry ashing technique was based on the preparation used in ASTM D4606-86 for determination of As and Se in coal. The acid digestion method used nitric and sulfuric acids heated by microwaves in sealed vessels. The digested color additives were analyzed for As by using hydride generated from sodium borohydride mixed with the acidified solution on a flow injection system leading to an atomic absorption spectrometer. Dry ashing was preferable to wet digestion because wet digestion yielded poor recoveries of added As. Dry ashing followed by hydride generation AAS gave determination limits of 0.5 ppm As in the color additives. At a specification level of 3 ppm As, the precision of the method using dry ashing was ± 0.4 ppm (95% confidence interval).
Residues of Chlormequat and Mepiquat in Grain—Results from the Danish National Pesticide Survey
Authors: Juhler René K , Vahl Martin 
Published: February 2020

Abstract
The objective of the present work was to establish information on chlormequat and mepiquat residues in grain for human consumption. Chlormequat (2- chloro-N,N,N-trimethylethylammonium, CAS RN 7003-89-6) and mepiquat (1,1-dimethylpiperid- inium, CAS RN 15302-91-7) are plant growth regulators used to stabilize stalks in cereals. The study was part of the Danish National Pesticide Survey, managed by the Danish Veterinary and Food Administration. Samples were collected in autumn 1997. Residue contents were determined with a newly developed liquid chromatographic- tandem mass spectrometric (LC-MS/MS) method for chlormequat analysis. The method was extended to include mepiquat in the present study. Quantitation was done by the internal standards method, using mass chromatograms of the most intense daughter ions of mepiquat (m/z 98), chlormequat (m/z 58), and [13C]-chlormequat (m/z 61, internal standard). For chlormequat, the overall limit of detection (LD) was 6 μg/kg and the limit of determination (LOD) was 10 μg/kg. For mepiquat, LD was 2 μg/kg and LOD was 3 μg/kg. Of 77 samples analyzed, 51 contained chlormequat and 11 contained mepiquat. The highest levels of chlormequat were found in samples of oatmeal (3.76 mg/kg) and rye (1.08 mg/kg). In 9 rye grain samples containing chlormequat, 5 also contained mepiquat. However, in all samples analyzed, the residues of chlormequat and mepiquat were below maximum residue limits.
Chemically Modified Silica Gel with Mercaptopropyltrimethoxysilane as Stationary Phase in Thin-Layer Chromatography
Authors: Marutoiu Constantin , Constantinescu Rodica , Dogar Florenta , Grecu Rodica 
Published: February 2020

Abstract
A polar silica gel R chemically modified with mercaptopropyltrimethoxysilane was prepared. Surface characteristics of the silica gel R before and after chemical modification were determinated by elemental analysis, specific surface area characterization, infrared spectroscopy, and thin-layer chromatography. Eight dyes were separated on the chemically modified silica gel R.
Use of Microwave Digestion and Atomic Absorption Spectrophotometry To Determine Chromic Oxide as a Digestibility Marker in Feed, Feces, and Ileal Content
Authors: García-Rico Leticia , Ruiz Rita E Ramos , Coronado Lourdes Gutiérrez 
Published: February 2020

Abstract
Most conventional digestion procedures, such as dry ashing and wet ashing, are tedious and labor intensive. Microwave digestion is agood alternative, because microwave dissolution is faster, safer, and simpler, and provides more controlled reproducible conditions than conventional methods. The purpose of this study was to develop a microwave digestion method for mineralizing meat and bone meal diets, feces, and ileal contents. Each sample was heated on a hot plate for 10 min, dry ashed at 65°C for 4 h, and transferred into microwave vessels. Then, 10 mL 70% HNO3 was added. Samples were digested for 7,10, and 20 min at 95,90, and 85% power, respectively. After the heating cycle, 6 mL 30% H2O2 was added, and samples were returned to the microwave for a second heating cycle of 1 and 7 min at 95 and 90% power, respectively. Finally, chromium concentration was determined by flame atomic absorption spectrophotometry. The digestion method was validated by using a standard reference material, SRM domestic sludge 2781, with a certified chromium value of 195 ± 9 μg/g. The value obtained in this study was 178 ± 11 μg/g, for a difference of 17 μg/g. Spike recovery experiments resulted in 103.16 and 100.35% recoveries of chromium from diet and feces samples, respectively. Coefficients of variation were 10.8 and 7.8%, respectively.
Determination of Avilamycin in Poultry Feeds by Liquid Chromatography
Authors: Scott Charles A , Yordy Durand W , Coleman Mark R 
Published: February 2020

Abstract
Avilamycin was extracted from feed with acetonitrile. Isolation of avilamycin factors from feed matrix interference was accomplishedby normal phase solid-phase extraction with silica as sorbent. Reversed-phase liquid chromatography was subsequently used to separate and quantitate the primary biologically activefactors A and B for determination of chemical potency. This method combines specificity for avilamycins A and B in poultry feeds with simple sample preparation that removes matrix interferences. Recoveries of factor A ranged from 93.29 to 97.26%, with precision (relative standard deviation) ranging from 1.1to 3.4%. Avilamycin factors in feed samples tested ranged from 4.45 to 17.82 μg/g for factor A and from 0.80 to 3.18 μg/g for factor B.
Salmonella in Foods—A New Enrichment Procedure for Use with the TECRA Salmonella Visual Immunoassay: Collaborative Study
Authors: Hughes Denise , Dailianis Angela E , Hill Louise , Curiale Michael S , Gangar Vidhya ,   Collaborators:, Arnold Don , Barrat Christine , Baxter Trisha , Bell Jim , Brooks Robert , Bryant Dennis , Burke Kylie , Burnie Adrienne , Clifford David , Daniels Karen , Danisavich Tom , Deiss Karen , Armando D’Onorio , Faucher Karla , Finkenbiner Dwain , Gangar Vidhya , Gasanov Uta , Gebler Jill , Gerry Ann , Graham Doris , Graham Trudy , Harris Patrick , Hetrick Susan , Hill Louise , Jurgens Jodi , Keating Kathy Jost , Klokman Renee , Le Cherie , Matrozza Mark , McCarthy Rachel , McCawley Cameron , Munyard Steven , Pye Victoria , Rajkowski Kathleen , Ristov Katerina , Rosinko Joyce , Schneider Keith , Schubert Mary Jane , Sloan Edna , Souter Freya , Wilson Maurice , Zuroski Kristy 
Published: February 2020

Abstract
A collaborative study was conducted to compare a new enrichment procedure for the TECRA Salmonella Visual Immunoassay with the reference method given in the U.S. Food and Drug Administration’s Bacteriological Analytical Manual (BAM 7th Ed.). Three food types (milk powder, black pepper, and soy flour) were analyzed in Australia, and 3 food types (milk chocolate, dried egg, and rawturkey) were analyzed in the United States. Thirty eight collaborators participated in the study. No significant differences (p &gt; 0.05) were observed for the pairwise comparison of the proportion of positive samples forthe TECRA method with that for the reference method. The new enrichment procedure for the TECRA method has been adopted First Action by AOAC INTERNATIONAL.
Analysis of β-Carotene in Medical Food by Liquid Chromatography with Matrix Solid-Phase Dispersion
Authors: Chase G William , Eitenmiller Ronald R , Long Austin R 
Published: February 2020

Abstract
A liquid chromatographic method is described for analysis of β-carotene in medical food. The nutrient is extracted from medical food without saponification by matrix solid-phase dispersion and quantitated by isocratic normal-phase chromatography with a Si 60 column and a mobile phase of hexane containing 0.125% (v/v) isopropyl alcohol. The limit of quantitation is 0.02 μg/mL at 436 nm. Standard response was linear over the concentration range of 0.02μ1.0 μg/ml(r2 = 0.99998). Recoveries were determined on a zero control reference material containing added β-carotene at various levels. Recoveries averaged 91.2% (n = 25) with coefficients of variation from 0.50 to 3.10%. The method provides a rapid, specific, sensitive, and easily controlled assay for analysis of β-carotene in fortified medical food. In addition, retinyl palmitate can be assayed simultaneously with an in-line fluorescence detector.
Determination of Fat, Protein, and Total Solids in Ovine Milk by Near-Infrared Spectroscopy
Authors: Albanell Elena , Cáceres Paloma , Caja Gerardo , Molina Ester , Gargouri Ahmed 
Published: February 2020

Abstract
Analysis by near-infrared spectroscopy (NIRS) was investigated as a means of predicting quality parameters of ovine milk. Calibration equations were developed with samples of ovine milk obtained from a flock of Manchega and Lacaune dairy ewes at different stages of lactation for a wide variation in milk composition. Prediction equations for milk protein, fat, and total solids content were developed by use of reflection or transflection methods to measure absorbance values. Accuracies of measurements were compared. R2 (squared multiple correlation coefficient) values were satisfactory in most cases. The highest R2 value for milk protein content (0.92) was obtained in transflectancemode with unhomogenized milk. The highest R2 values for fat (0.99) and total solids (0.98–0.96) content were obtained in both a transflectance mode without sample conditioning and in a transflec tance mode with milk homogenized at 40°C. To validate the calibration, an independent set of 40 milk samples was used. The best r2 (simple correlation coefficient) values for protein, fat, and total solids were 0.92, 0.97, and 0.92, respectively. The study showed that NIRS is a potentially useful technique for evaluating the composition of unhomogenized ovine milk.
Validation of a Gas Chromatographic Method for Determining Fatty Alcohols that Compose Policosanol in Five-Milligram Film-Coated Tablets
Authors: Canavaciolo Victor L González , Hernández Juan Magraner 
Published: February 2020

Abstract
A gas chromatographic method using a packed column and 1-eicosanol as an internal standard was developed and validated for determination of the aliphatic fatty alcohols that compose policosanol in 5 mg film-coated tablets. The alcohols were analyzed as trimethylsilyl (TMS) derivatives, prepared with N-methyl-N-trimethylsilyltrifluoroacetamide. The method can detect degradation products with high retention times without interfering with the peaks of the active principle. Good linearity (correlation coefficient = 0.9996) and accuracy (recovery = 100.44%) were proven over a range of 50-150% of the nominal concentration. Within-day and between-day precisions at the nominal 100% value met the acceptance criteria (&lt;2%). Ruggedness was examined through an intralaboratory experimental study in which 7 operational changes were made and the observed results were quantitation, repeatability, resolution, and relative retention time. Among these results, only the relative retention time (tC28,C20) was significantly affected when the column used was 2.1 m instead of 3.1 m. Repeatability and reproducibility (r = 0.1506 and R = 0.2450, respectively) were obtained from a uniform-level interlaboratory test. The method is suitable for quality control and stability studies of these tablets.
Routine Detection of Salmonella Species in Water: Comparative Evaluation of the ISO and PROBELIA™ Polymerase Chain Reaction Methods
Authors: Coquard Dominique , Exinger Alfred , Jeltsch Jean-Marc 
Published: February 2020

Abstract
Water is one of the main transmission routes for Salmonella spp., the causative agents of salmonellosis in humans and animals. This worldwide sanitary problem requires rapid and accurate analyses to be realized so that advisories for exposed people are timely and reliable. Because the traditional method, the ISO 6340 method, does not meet the criterion of rapidity, there was a need for a quicker method. To fulfill this need, a comparative evaluation between the ISO method and one based on polymerase chain reaction (PCR), the PROBELIA, was performed. Waters from different origins were tested either directly or after artificial contamination with selected Salmonella strains isolated from the environment. The results clearly demonstrate that the PCR-based method can advantageously replace the ISO 6340 method. It is quicker, less labor intensive, reproducible, and provides results that match perfectly to those obtained by the ISO method. Furthermore, the PROBELIA method meets the requirements for an efficient sanitary survey: high numbers of samples processed at the same time, reduced cost, and results within 2 days.
Optimization and Validation of a Minicolumn Method for Determining Aflatoxins in Copra Meal
Authors: Arim Rosario H , Aguinaldo Aida R , Tanaka Toshitsugu , Yoshizawa Takumi 
Published: February 2020

Abstract
A minicolumn (MC) method for determining aflatoxins in copra meal was optimized and validated. The method uses methanol–4% KCI solution as extractant and CuSO4 solution as clarifying agent. The chloroform extract is applied to an MC that incorporates “lahar,” an indigenous material, as substitute for silica gel. The “lahar”-containing MC produces a more distinct and intense blue fluorescence on the Florisil layer than an earlier MC. The method has a detection limit of 15 μg total aflatoxins/kg sample. Confirmatory tests using 50% H2SO4 and trifluoroacetic acid in benzene with 25% HNO3 showed that copra meal samples contained aflatoxins and no interfering agents. The MC responses of the copra meal samples were in good agreement with their behavior in thin-layer chromatography. This modified MC method is accurate, giving linearity-valid results; rapid, being done in 15 min; economical, using low-volume reagents; relatively safe, having low-exposure risk of analysts to chemicals; and simple, making its field application feasible.
Application of Polymerase Chain Reaction–Single Strand Conformational Polymorphism (PCR–SSCP) to Identification of Flatfish Species
Authors: Céspedes Ana , García Teresa , Carrera Esther , González Isabel , Carrera Esther , Fernández Alicia , Hernández Pablo E , Martín Rosario 
Published: February 2020

Abstract
A method of DNA analysis based on polymerase chain reaction–single strand conformational polymorphism (PCR–SSCP) was developed to verify the authenticity of labeled raw and frozen fillets of some flatfish species. PCR was used to amplify a short fragment (201 bp) of the mitochondrial cytochrome b gene, which was denatured and analyzed by native polyacrylamide gel electrophoresis for detection of SSCPs. Species-specific patterns of DNA bands were obtained for sole (Solea solea), European plaice (Pleuronectes platessa), flounder (Platichthys flesus), and Greenland halibut (Reinhardtius hippoglossoides).
Multiresidue Determination and Confirmation of Imidazolinone Herbicides in Soil by High-Performance Liquid Chromatography/Electrospray Ionization Mass Spectrometry
Authors: Krynitsky Alexander J , Stout Steven J , Nejad Huns , Cavalier Thomas C 
Published: February 2020

Abstract
A new multiresidue method was developed to determine 6 imidazolinone herbicides in 5 different soil types, using high-performance liquid chromatography/electrospray ionization mass spectrometry (HPLC/ESMS). Good recoveries and sensitivity were obtained for the compounds investigated at the 2.0 ppb limit of quantitation. A 50 g portion of soil was extracted with 0.5N NaOH. A portion of the extract was acidified to precipitate humic acids, and the supernatant was loaded onto a preconditioned tC-18 solid-phase extraction (SPE) cartridge and eluted with ethyl acetate. Further cleanup was achieved by using a tandem strong-anion-ex- change SPE/strong-cation-exchange (SCX) SPE. Analytes were eluted from the SCX SPE with saturated KCI in methanol. After cleanup, the sample was desalted with an RP-102 SPE cartridge. Quantitation was achieved by monitoring the [M + H]+ ions for each compound, with a time-scheduled selective-ion-monitoring program (positive mode). The extraction and cleanup procedure produced a purified extract for MS confirmation using 3 ions with “in-source” collision-induced dissociation.