bluuebunny/crossref_metadata_2025_split huggingface dataset:
Re-Evaluation of Selectivity of Malachite Green Test for Presence of Sulfite in Mechanically Deboned Poultry
Authors: Mallinson Edward T , Curry Kevin A , Corrao Paul A 
Published: February 2020

Abstract
A study was undertaken to determine whether free chlorine or sulfide anions could yield positive results for the malachite green test in meat samples when sulfite was not present. Malachite green solution was added to a mechanically deboned poultry (MDP) sample spiked with either chlorine or sulfide ions. The presence of chlorine in MDP samples at any concentration tested did not yield a positive reaction for the malachite green test. When sulfide ions were introduced into MDP samples, positive results were observed at 40 μg sulfide ion/g MDP and above. Because aqueous solutions of sulfide at the levels mentioned have a relatively high pH, it was necessary to determine whether the pH or the presence of the sulfide ions had caused this positive reaction to the malachite green test. After a comparison of a solution of sulfide, and a solution of a matching pH, it was observed that the sulfide present caused the positive reaction to the malachite green test.
Liquid Chromatographic Method for Perphenazine and Its Sulfoxide in Pharmaceutical Dosage Forms for Determination of Stability
Authors: Beaulieu Normand , Lovering Edward G 
Published: February 2020

Abstract
A liquid chromatographic method is described for determination of perphenazine and perphenazine sulfoxide in representative dosage forms. Sulfoxide levels were nondetectable or less than 1% in tablets and in an injectable product. Sulfoxide levels increase with time in some syrup formulations and may be as high as 11% in syrup formulations before their expiration date.
Liquid Chromatographic Determination of Levodopa, Levodopa-Carbidopa, and Related Impurities in Solid Dosage Forms
Authors: Ting Susan 
Published: February 2020

Abstract
A rapid reverse phase liquid chromatographic method was developed for the determination of levodopa and levodopa-carbidopa in tablets and capsules. The method also separates these drugs from 3-(3,4,6- trihydroxyphenyl)alanine and methoxytyrosine, impurities of levodopa, and from methyldopa and 3-O-methylcarbidopa, impurities of carbidopa. The mobile phase was 3% acetic acid and the detection wavelength was 280 nm. The method was linear over the concentration range 0.05-0.40 mg levodopa/mL, 0.01-0.06 mg carbidopa/mL, 0.9- 12.8 μg 3-(3,4,6-trihydroxyphenyl)alanine/mL, 0.7-3.1 μg methyldopa/ mL, 5-20 μg methoxytyrosine/mL, and 0.5-3.3 μg 3-O-methylcarbidopa/ mL. Mean recoveries (%) for spiked commercial tablets were: levodopa 100.3, carbidopa 100.4, 3-(3,4,6-trihydroxyphenyl) alanine 99.1, methoxytyrosine 100.0, methyldopa 100.0, and 3-O-methylcarbidopa 99.4.
Analysis of Pharmaceutical Dosage Forms for Oxfendazole: I. Reverse Phase Liquid Chromatographic Determination of Oxfendazole in Swine Premix
Authors: Fleitman Jeffrey , Neu Daniel , Visor Gary 
Published: February 2020

Abstract
A reverse phase liquid chromatographic (LC) procedure is described for quantitating oxfendazole (2-(methoxycarbonylamino)-5-phenyIsuIfinylbenzimidazole)) in swine premix. Sample preparation consists of extracting oxfendazole with an acetone-methanol mixture. An aliquot of the extract is then centrifuged to separate undissolved premix excipients. Internal standard is added to the supernate and the sample is further diluted with water-acetonitrile-phosphoric acid (80 + 20 + 1). Oxfendazole is quantitatively determined using a Partisil-5-ODS-3 column with acetonitrile-O.OlM phosphate buffer (pH 6.0) as the mobile phase. The method is stability specific and yields a mean recovery of 101.1 ± 0.4% for the 1.35% premix formulation. The dependence of chromatographic performance characteristics on mobile phase organic content, pH, and buffer concentration is also reported.
Simultaneous Determination of Vitamins B2 (Riboflavin) and B6 (Pyridoxine) in Infant Formula Products by Reverse Phase Liquid Chromatography
Authors: Ayi Benjamin K , Yuhas David A , Deangelis Nicholas J 
Published: February 2020

Abstract
An ion pair liquid chromatographic (LC) method is described for the simultaneous determination of vitamins B2 and B6 in infant formula products. The method eliminates many of the UV absorbing ingredients present in the infant formulations. The method involves extraction of the vitamins with distilled water followed by a filtration step and the subsequent analysis of the filtrate by LC. Vitamins B2 and B6 and their vitamers are separated from each other as well as from ingredients in the sample matrix on a 5 µm Spherisorb ODS column. The mobile phase consists of 85% 0.04M triethylammonium phosphate (pH 3.0), 10% methanol, 5% acetonitrile, and the counter ion, octane sulfonic acid sodium salt. The method is reproducible for both vitamins with relative standard deviations (RSD) ranging from ± 0.3 to ± 2.6% depending on the infant formula product. The recoveries of the vitamins from various infant formula products are greater than 97%. The analysis for vitamins B2 and B6 in various lots of infant formula compared well with the official AOAC methods.
Liquid Chromatographic Determination of Basic Nitrogen-Containing Polynuclear Aromatic Hydrocarbons in Smoked Foods
Authors: Joe Frank L , Salemme Jean , Fazio Thomas 
Published: February 2020

Abstract
Several smoked foods were analyzed for basic nitrogen-containing polynuclear aromatic hydrocarbon (NPAH) content by a relatively rapid liquid chromatographic (LC) technique. The analyzed products included both domestic and imported market basket commodities. Nanogram quantities of NPAH standards were detected by UV and fluorescence detectors connected in series. The NPAHs were extracted from basic aqueous ethanolic solution into cyclohexane, extracted from cyclohexane into 6N HC1, and extracted back into cyclohexane after neutralization of the acid. The NPAHs were then purified by filtering the extract through deactivated basic alumina. The eluate from this step was concentrated to dryness, and the residue was dissolved in 95% ethanol and analyzed by LC, using a Vydac C-18 column and acetonitrile-water (9 + 1) as the mobile phase. Recoveries of 3 NPAHs, 5,7-dimethylbenz(a)acridine, dibenz(aj)acridine, and dibenz(a,h)acridine, each added to salmon and sausage at the 5 ppb level, ranged from 62 to 101% by fluorescence measurement and from 64 to 106% by UV measurement. None of the NPAHs used as standards were found by either fluorescence or UV detection at levels ≥5 ppb in any of the foods analyzed.
Fluoroacetate Residues in Ground Squirrel and Coyote Tissues Due to Primary or Secondary 1080 Poisoning
Authors: Casper Howard H , Mount Michael E , Marsh Rex E , Schmidt Robert H 
Published: February 2020

Abstract
Fluoroacetate residues in various tissues of 1080-poisoned ground squirrels and coyotes are listed. The tissues (excluding the stomach) of squirrels poisoned with an average of 0.8 mg 1080/kg (low dose) contained from 182 to 1309 ppb fluoroacetate. In squirrels poisoned with an average of 4.8 mg 1080/kg (high dose), the tissue residues ranged from 535 to 9754 ppb fluoroacetate. Tissues from coyotes which died after consuming 1080-poisoned ground squirrels were also analyzed for fluoroacetate residues. Residues in these coyote kidneys and livers ranged from less than 10 ppb to 95 ppb fluoroacetate. The residue findings in this research indicate that a diagnostic assay for 1080 in tissues must be reliable at 10 ppb (or less) fluoroacetate
Determination of Ampicillin Residues in Fish Tissues by Liquid Chromatography
Authors: Nagata Tomoko , Saeki Masanobu 
Published: February 2020

Abstract
A liquid chromatographic (LC) method is described for determination of ampicillin residues in fish tissues. The drug is extracted from tissues with methanol, and the extract is evaporated to dryness. This residue is cleaned up by Florisil cartridge chromatography. LC analysis is carried out on a Nucleosil C18 column, and ampicillin is quantitated by ultraviolet detection at 222 nm. Recoveries of ampicillin added to tissues at levels of 0.2 and 0.1 ppm were 73.2 and 61.5%, respectively. The detection limit was 3 ng for ampicillin standard, and 0.03 ppm in tissues.
Gas Chromatographic Determination of Fensulfothion in Formulations: Collaborative Study
Authors: Betker William R ,   Collaborators:, Balcer E W , Bennett O O , Coffman W R , DiPilla E J , Hodgins W E , Karr J J , Koenig D K , Korger P D , Meinen V J , Owen M E , Riggs T H , Schulz R , Tengler H , Zank T L 
Published: February 2020

Abstract
A collaborative study was conducted on a gas chromatographic method for determination of fensulfothion. Eleven laboratories analyzed 2 technical and two 6 lb/U.S. gal. spray concentrate samples. In the analysis, samples are dissolved in methylene chloride which contains 4-chlorophenyl sulfoxide as an internal standard, and solutions are injected into a gas chromatograph equipped with an OV-330 column. Withinlaboratory repeatability was 0.79% for technical product and 0.37% for the spray concentrate samples, with coefficients of variation of 0.88 and 0.58%, respectively. Among-laboratories reproducibility was 0.81% for technical product and 0.53% for the spray concentrate, with coefficients of variation of 0.91 and 0.84%, respectively. The method has been adopted official first action.
On-Line Generation of Cyanogen Chloride in Semiautomated Determination of Niacin and Niacinamide in Food Products
Authors: Ge Hoon , Oman Gary N , Ebert Frank J 
Published: February 2020

Abstract
The current AOAC procedure for semiautomated determination of niacin specifies the use of externally generated cyanogen bromide. Because of the safety concerns in handling this material, we investigated the use of an alternative system of generating cyanogen chloride in situ, using chloramine-T and potassium cyanide. Recovery studies conducted on 9 different food products yielded average recoveries of 101 %. A repeatability study resulted in a measured coefficient of variation of 2.9%. The AOAC niacin method was compared with this semiautomated method; 115 paired analyses on 8 different food types over 6 separate analytical replications indicated no significant difference by a paired t-test at the 95% confidence level.
Liquid Chromatographic Determination of Major Organic Acids in Apple Juice and Cranberry Juice Cocktail: Collaborative Study
Authors: Coppola Elia D , Starr Martin S ,   Collaborators:, Chang G H , DeVries J , Durst R , Elkins E , Frost B , Funk B , Hastings H J , Lento H G , Morawski S , Munsey J , Post S , Reese B L , Rovella M A , Schmoeger D R , Schwartz H , Smith W , Thomas L V , Thornburg W H , Virkler W , Wrolstad R E , Wu A , Zurawski J W 
Published: February 2020

Abstract
Twelve laboratories collaboratively studied a liquid chromatographic method for determination of quinic, malic, and citric acids in cranberry juice cocktail and apple juice. Samples are passed through a disposable silica cartridge, filtered, and directly injected into the chromatograph. The mobile phase is 0.2M KH2PO4 (pH 2.4). Two reverse phase columns are used, with UV detection at 214 nm. Six samples of cranberry juice cocktail and 6 samples of apple juice were sent to each collaborator. Repeatability and reproducibility coefficients of variation ranged from 1.2 to 7.6% and from 2.9 to 14.7%, respectively, for quinic, malic, and citric acid levels above 0.10%. The precision of the method is satisfactory. The method has been adopted official first action.
Development of Machine Smoking Parameters for Measurement of Cigarette Tar Yield in the United Kingdom
Authors: Johnson Joseph C 
Published: February 2020

Abstract
The smoking and analytical methods used by government and tobacco industry laboratories are the result of many years of collaborative work within the industry and through international bodies such as the International Standards Organization. Recently, some publications have criticized the validity and scientific soundness of these procedures. It is shown that such criticisms are totally unfounded by reviewing the work that led to the adoption of the current technique. Tar tables, published by the UK Health Departments are valid in ranking brands in order of their yields, while not necessarily reflecting the absolute tar delivery to the smoker. These tables are intended to and do provide a relevant guide for smokers about the proportional tar yields of UK cigarettes.
Gas Chromatographic Determination of Histapyrrodine Hydrochloride in Pharmaceutical Preparations
Authors: Sane Ramesh T , Doshi Vipul J , Joshi Sanjay K , Shastri Vijay K , Sapre Dhananjay S , Jukar Swati , Sawant Satish V 
Published: February 2020

Abstract
A simple gas chromatographic method is described for the determination of histapyrrodine HC1 in marketed formulations. Chlorpheniramine maleate is used as the internal standard. The amount of histapyrrodine HC1 found by the proposed method averaged 19.91 mg/tablet, compared with the label claim of 20 mg/tablet. The method was statistically evaluated for accuracy and precision.
Liquid Chromatographic and Spectroscopic Characterization of Pentamidine Isethionate and Impurities in Bulk Drug and Injectables
Authors: Mount Dwight L , Miles James W , Churchill Frederick C 
Published: February 2020

Abstract
A liquid chromatographic (LC) method is described for evaluating purity of pentamidine isethionate (PI), a life-saving drug used in the treatment of Pneumocystis carinii pneumonia, which is a leading cause of death in persons with acquired immunodeficiency syndrome (AIDS). Six potential impurity compounds were synthesized to test the selectivity of the chromatographic system and to permit quantitation of impurities in various lots of PI products. The drug and impurities were separated with gradient elution on a cyano-bonded LC column. The analytic system provided information on the identities and levels of impurities in early experimental lots of PI. These results assisted the manufacturer in altering reaction conditions and purification procedures to ensure that succeeding lots were within the specification limits, i.e., no more than 0.4% of any single impurity or 0.7% of total impurities found in the final product.
Liquid Chromatographic Determination of Multiresidue Fluorescent Derivatives of Lonophore 1 Compounds, Monensin, Salinomycin, Narasin, and Lasalocid, in Beef Liver Tissue
Authors: Martinez Elizabeth E , Shimoda Wilbert 
Published: February 2020

Abstract
A liquid chromatographic (LC) method with fluorometric detection was developed to quantitatively determine residue levels of monensin, salinomycin, narasin, and lasalocid in beef liver tissue. The ionophores are extracted from the tissue, purified by both alumina and Sephadex LH-20 column chromatography, and then derivatized. Lasalocid was directly esterified with 9-anthryIdiazomethane (ADAM), but monensin, salinomycin, and narasin were first acetylated with acetic anhydride and then esterified with ADAM. The ADAM derivatives were purified on a silica gel column and separated by LC using an RP C-8 5 μm column. A fluorescence detector set at 365 nm (excitation) and 418 nm (emission) was used to monitor the column effluent. The detection limits were 0.15 ppm, and the calibration curves were linear between 0.5 and 5.0 ppm for all 4 ionophores. Mean recoveries were 57, 70, 75, and 90% for lasalocid (5 ppm), monensin (2.5 ppm), salinomycin (2.5 ppm), and narasin (2.5 ppm), respectively. The ionophores were also separated and semiquantitated by using bioautography and thin layer chromatography with a vanillin spray.
Determination of Trace Metals in Low Ionic Strength Waters Using Zeeman and Deuterium Background Correction for Graphite Furnace Atomic Absorption Spectrometry
Authors: Fishman Marvin J , Perryman Gary R , Schroder LeRoy J , Matthews Edward W 
Published: February 2020

Abstract
Each U.S. Geological Survey water quality laboratory evaluated one of 2 background correction techniques: Zeeman and deuterium. A L’vov-type platform was used to determine cadmium, chromium, cobalt, copper, lead, manganese, nickel, and zinc in low ionic strength waters, submitted as blind samples. Matrix modifers were used to determine cadmium, chromium, lead, manganese, and zinc. Results were comparable for all metals, except cadmium and nickel, at the μg/L range. Analytical ranges for a 20 μL sample volume are presented. Detection limits can be changed by varying the volume of sample injected, by using multiple injections, or by changing the analytical wavelength.
Gas Chromatographic Determination of Butachlor in Formulations: Collaborative Study
Authors: Tomkins David F ,   Collaborators:, Baird J , Bowermaster J , Brunhouse E , Caparoon W C , Chenery L T , Galoux I M , Gentry G M , Hodgins W E , Jurgens D , Koenig D K , Law M W , Lee B , Liu J , McAfee S E , Spencer D A , Torma L 
Published: February 2020

Abstract
An isothermal gas chromatographic (GC) method for measuring butachlor in formulations was tested by 15 laboratories. Samples were prepared in acetone and determined using a GC column of 10% SP-2250 on 100-120 mesh Supelcoport, and triphenyl phosphate as internal standard. Collaborators made single determinations on each of 2 similar materials (matched pairs) on 2 days for 2 pairs of samples. The study generated 56 matched pairs which were used in Youden’s matched pair calculations. Coefficients of variation (CV,) for liquid formulations were 1.06 and 0.98%. The method was simple to use and did not reveal any interferences in the samples tested. The method has been adopted official first action as an AOAC-CIPAC method.
Simultaneous Liquid Chromatographic Determination of Some Tetracyclines in Serum
Authors: Tyczkowska Krystyna , Aronson Arthur L 
Published: February 2020

Abstract
A sensitive liquid chromatographic method has been developed for the simultaneous determination of oxytetracycline, minocycline, tetracycline, and doxycycline in serum. A serum sample is vortex-mixed with a solution of mobile phase for tetracyclines and 2% (v/v) phosphoric acid. The mixture is filtered using a 30 000 molecular weight cutoff microseparation tube which separates high-molecular-weight solutes following low-speed centrifugation. Tetracyclines are separated from other serum components by reverse phase liquid chromatography (LC) with buffered methanol mobile phase. Ultraviolet absorbance of the column effluent is monitored at 267 nm. Concentrations as low as 0.2 μg/mL of tetracyclines in serum are quantitatable, with recoveries from 76.2 to 102.6% and coefficients of variation from 2.69 to 5.36%. The method has been tested in bovine, porcine, equine, caprine, ovine, canine, feline, and avian (turkey) serum.
Interlaboratory Comparison of Analyses for Heavy Metals in Clam Tissue
Authors: Hendzel Marilyn R , Fallis Bruce W , Demarch Brigitte G E 
Published: February 2020

Abstract
Results are reported for an interlaboratory study conducted to assess the reproducibility of analyses for lead, copper, cadmium, and zinc. The 10 participating laboratories analyzed 2 samples of freeze-dried clam tissue and 1 disguised sample of NBS Oyster Tissue. Interlaboratory variations were observed for all metals, although the methods yielded reproducible data for Cu and Zn with average interlaboratory coefficients of variation of 15 and 11%, respectively. The performance of methods used for Cd and, more so, for Pb was less than satisfactory. Cadmium levels in the 3 samples ranged from about 0.7 to 3.7 ppm with an average interlaboratory coefficient of variation (CV) of 24%. Lead levels in the 3 samples were about 0.5 ppm with an interlaboratory CVof 68%. Some laboratories' results were consistently high or low but data were insufficient to relate these trends to one particular variable. Results from this study were compared with 5 other studies reported in the literature since 1980. Coefficients of variation from all studies were comparable for samples with similar metal concentrations
Liquid Chromatographic Determination of Bendiocarb in Technical Materials and Wettable Powder Formulations: Collaborative Study
Authors: Carter Peter L , Overton Keith C ,   Collaborators:, Baker P G , Bennett O O , Brown M , Carlstrom A A , Claussen K , Dobrat W , Freedlander R S , Hamilton D G N , Hitos P , Hodgins E , Kaiser L , McDermott W H , Minyard J P , Noel R J , Montgomery W A , Pauling K O , Pavel K , Tyler J F , Vinson D W 
Published: February 2020

Abstract
A liquid chromatographic method for determination of bendiocarb in technical materials and wettable powders was tested by 12 collaborators. Bendiocarb is dissolved in acetonitrile containing 0.1% propiophenone as internal standard. This solution is analyzed on a liquid chromatograph utilizing a reverse phase (C18) column. The compound is detected at 254 nm and peak area is used for quantitation. The 3 different materials studied contained 20, 80, and nominally 100% bendiocarb. Each was examined in duplicate to provide the necessary matched pairs. Collaborators approved of the ease and simplicity of the method and, in particular, the way the method can be applied to automatic injection assemblies. The statistical data show acceptable precision of the method: Reproducibility coefficients of variation were 20% material, 2.04%; 80% material, 1.02%; and nominal 100% material (technical product), 0.64%. The method has been adopted official first action.
Evaluation of Asparagine in the AOAC Use-Dilution Method
Authors: Cole Eugene C , Rutala William A 
Published: February 2020

Abstract
An asparagine solution (0.1%) is required in the AOAC use-dilution method to cover stainless steel carriers during sterilization and storage. The rationale for using an asparagine soak is unclear. It has been proposed that asparagine enhances bacterial adherence to carriers or inhibits corrosion of the metal carriers or both. The former theory was assessed in this study by comparing bacterial adherence on seeded carriers stored in 0.1 and 1% asparagine solution to those stored dry or in water. The anticorrosive properties of asparagine on stainless steel carriers were microscopically evaluated after 9 months. The results demonstrate that asparagine neither enhances bacterial adherence to carriers nor is necessary to prevent corrosion.
Validation of Liquid Chromatographic Method for Assay of Calcitriol and Alfacalcidol in Capsule Formulations
Authors: Flann Bruce C , Lodge Bruce A 
Published: February 2020

Abstract
The validation of a liquid chromatographic procedure suitable for the determination of calcitriol and alfacalcidol in their respective formulations labeled to contain at least 0.25 μ.g drug per unit is described. The capsule content is diluted and chromatographed in 15-20 min on silica columns (5 μm) with a mobile phase of hexane-tetrahydrofuranmethylene dichloride-isopropanol (72 + 12 + 12 + 4, v/v) with detection at 254 nm. The calibration curve is linear. Recoveries of “spikes” averaged 101% with a standard deviation of 2%. Precision was better than 1.5%.
Bioautographic Method for Evaluation of Glycopeptide Actaplanin in Milk
Authors: Bories Georges F , Baradat Maryse M , Corpet Denis E 
Published: February 2020

Abstract
A bioautographic method is described that allows the identification and semiquantitation of residues of the glycopeptide antibiotic actaplanin in cow’s milk at 0.01 ppm. The milk sample is precipitated with acetonitrile and the resultant pellet is extracted by a buffer. This extract is defatted, then chromatographed on an Amberlite resin column. Actaplanin is eluted with methanol-HCI. Purified extract is then chromatographed on a cellulose thin layer, developed in a methanol-chloroform- ammonium hydroxide mixture. This thin layer chromatography increased the sensitivity of the determination by concentrating the actaplanin components in a single spot. The antibiotic was then detected by bioautography, using Bacillus subtilis as a test organism. Parameters influencing the diffusion of the antibiotic (namely, the nature and concentration of the agar-agar), and the sensitivity of the test strain (namely, the nutritional value of the medium, and the addition of a synergistic inhibitor) have been optimized.