bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of Rosuvastatin in the Presence of Its Degradation Products by a Stability-Indicating LC Method
Authors: Mehta Tushar N , Patel Atul K , Kulkarni Gopal M , Suubbaiah Gunta 
Published: February 2020

Abstract
A forced degradation study was successfully applied for the development of a stability-indicating assay method for determination of rosuvastatin Ca in the presence of its degradation products. The method was developed and optimized by analyzing the forcefully degraded samples. Degradation of the drug was done at various pH values. Moreover, the drug was degraded under oxidative, photolytic, and thermal stress conditions. Mass balance between assay values of degraded samples and generated impurities was found to be satisfactory. The proposed method was able to resolve all of the possible degradation products formed during the stress study. The developed method was successfully applied for an accelerated stability study of the tablet formulation. The major impurities generated during the accelerated stability study of the tablet formulation were matches with those of the forced degradation study. The developed method was validated for determination of rosuvastatin Ca, and the method was found to be equally applicable to study the impurities formed during routine and forced degradation of rosuvastatin Ca.
Simultaneous Determination of N-Butylscopolamine and Oxazepam in Pharmaceutical Formulations by First-Order Digital Derivative Spectrophotometry
Authors: Toral Maria Inés , Muñoz Marcelo A , Orellana Sandra L 
Published: February 2020

Abstract
A simple method has been developed for the simultaneous determination of N-butylscopolamine bromide and oxazepam in pharmaceutical formulations using first-order digital derivative spectrophotometry. Acetonitrile was selected as the solvent in which both compounds showed well-defined bands. Both analytes showed good stability in this solvent when solutions of the analytes were exposed to light and temperatures between 20° and 80°C. The simultaneous determination of both drugs was performed by the zero-crossing method at 226.0 and 257.0 nm for N-butylscopolamine and oxazepam, respectively. The linear range of determination was found to be 2.5 × 10−7 to 8.0 × 10−5 mol/L for N-butylscopolamine and 7.1 × 10−8 to 8.0 × 10−5 mol/L for oxazepam. A very good level of repeatability (relative standard deviation) of 0.2% was observed for N-butylscopolamine and oxazepam. The ingredients commonly found in pharmaceutical formulations do not interfere. The proposed method was applied to the determination of these drugs in pharmaceutical formulations (capsules).
Comparative Validation Study to Demonstrate the Equivalence of a Minor Modification to AOAC Methods 996.09, VIP® for EHEC and 996.10, Assurance EIA® EHEC with the Reference Culture Method for the Detection of Escherichia coli O157:H7 in Beef
Authors: Feldsine Philip T , Green Shannon T , Lienau Andrew H , Kerr David E 
Published: February 2020

Abstract
The Visual Immunoprecipitate Assay (VIP®) method for the detection of enterohemorrhagic Escherichia coli O157:H7 (VIP for EHEC) and Assurance® Enzyme Immunoassay (EIA) method for the detection of EHEC (EHEC EIA) are AOAC INTERNATIONAL Official Methods 996.09 and 996.10, respectively. A minor modification to the enrichment medium used in both methods has been developed. This modification, the BioControl modified EHEC medium™ (BioControl mEHEC™) provides a more cost-effective procedure with performance equivalent to that of the cultural method for detection of E. coli O157:H7 in beef.
Determination of Sodium in Foods by Flame Atomic Absorption Spectrometry after Microwave Digestion: NMKL Interlaboratory Study
Authors: Julshamn Kaare , Lea Per , Norli Hilde Skaar ,   Collaborators:, Floren S , Furnes T , Grønningen D , Haugsnes J , Jensen A , Jensen A H , Jiang L , Karjalainen S , Kildahl B T , Kivikari R , Lathi J , Løvhøyden F , Palmadottir H , Rasmussen L , Riebe M , Sloth J J , Wang-Andersen J 
Published: February 2020

Abstract
Nine laboratories participated in an interlaboratory method performance (collaborative) study of a method for the determination of sodium in foods by flame atomic absorption spectrometry after wet digestion, using a microwave oven technique. Before the study, the laboratories were able to practice on samples with defined sodium levels (pretrial test). The method was tested on a total of 6 foods (broccoli, carrot, bread, saithe fillet, pork, and cheese) with sodium concentrations of 1480–8260 mg/kg. The materials were presented to the participants in the study as blind duplicates, and the participants were asked to perform single determinations for each sample. The repeatability relative standard deviations (RSDr) for sodium ranged from 1.9 to 6.5%. The reproducibility relative standard deviations (RSDR) ranged from 4.2 to 6.9%. The HorRat values ranged from 0.9 to 1.6.
Quantitative Determination of Saccharides in Dietary Glyconutritional Products by Anion-Exchange Liquid Chromatography with Integrated Pulsed Amperometric Detection
Authors: Eberendu Alexis R , Booth Christy , Luta Gabriela , Edwards Joshua A , McAnalley Bill H 
Published: February 2020

Abstract
A new technique for the assay of carbohydrates is described in which separation and quantification of neutral saccharides, aminosaccharides, glycuronic acids, and disaccharides may be accomplished in less than 50 min of total run time. This method involves optimized anion-exchange liquid chromatography coupled with integrated pulse amperometric detection. Complex carbohydrates from various sources, including dietary supplements, were hydrolyzed in a dilute solution of trifluoroacetic acid, freeze-dried, and reconstituted in water containing 2-deoxygalactose as the internal standard. The solution was filtered and separated on CarboPac PA20 column. The eluted saccharides were detected by oxidation on a gold electrode with quadruple-pulsed integrated amperometry. The calibration plots for the saccharides were linear with an average correlation coefficient of 0.999. Method precisionc regarding peak retention time and resolution used in the peak identifications was verified. With this method, previously difficult-to-separate saccharides, such as galactosamine, glucosamine, and N-acetylglucosamine, were successfully resolved from the neutral saccharides rhamnose, arabinose, and galactose. Mannose was also resolved from xylose, and de-acetylation of aminosaccharides prior to separation was not necessary. This technique provides an accurate and efficient means to assay carbohydrates in dietary supplements, which new federal regulations will soon mandate.
Determination of Total Monomeric Anthocyanin Pigment Content of Fruit Juices, Beverages, Natural Colorants, and Wines by the pH Differential Method: Collaborative Study
Authors: Lee Jungmin , Durst Robert W , Wrolstad Ronald E ,   Collaborators:, Eisele T , Giusti M M , Hach� J , Hofsommer H , Koswig S , Krueger D A , Kupina; S , Martin S K , Martinsen B K , Miller T C , Paquette F , Ryabkova A , Skrede G , Trenn U , Wightman J D 
Published: February 2020

Abstract
This collaborative study was conducted to determine the total monomeric anthocyanin concentration by the pH differential method, which is a rapid and simple spectrophotometric method based on the anthocyanin structural transformation that occurs with a change in pH (colored at pH 1.0 and colorless at pH 4.5). Eleven collaborators representing commercial laboratories, academic institutions, and government laboratories participated. Seven Youden pair materials representing fruit juices, beverages, natural colorants, and wines were tested. The repeatability relative standard deviation (RSDr) varied from 1.06 to 4.16%. The reproducibility relative standard deviation (RSDR) ranged from 2.69 to 10.12%. The HorRat values were ≤1.33 for all materials. The Study Director recommends that the method be adopted Official First Action.
Evaluation of the Assurance GDS™ for E. coli O157:H7 Method and Assurance GDS for Shigatoxin Genes Method in Selected Foods: Collaborative Study
Authors: Feldsine Philip T , Green Shannon T , Lienau Andrew H , Stephens James , Jucker Markus T , Kerr David E ,   Collaborators:, Bark D , Belousov Y S , Benish B , Brillhart D E , Camacho A , Deans A , Douangmala A , Forgey; R , Grant M , Gringer G , Hunsucker J C , Hyunh P , Johnson K , Lockhart L D , Luebbert B , Metcalf M , Moser R , Norris C , Oostra K , Pickett J L , Potter L , Roa N , Solano S , Tuncan E , Vrana D , Wilson J 
Published: February 2020

Abstract
A multilaboratory collaborative study was conducted to compare the Assurance GDS™ for E. coli O157:H7 method and the reference culture methods for the detection of E. coli O157:H7 in orange juice, raw ground beef, and fresh lettuce. A separate companion assay, the Assurance GDS for Shigatoxin Genes method was also evaluated with the same test portions. Fifteen laboratories participated in the study. A Chi square analysis of each of the 3 food types at the high, low, and uninoculated control levels was performed. For all foods, the Assurance GDS for E. coli O157:H7 method and the Assurance GDS for Shigatoxin Genes method were equivalent to or better than the reference methods.
Determination of 1,3-Dichloropropanol in Soy Sauce and Related Products by Headspace Gas Chromatography with Mass Spectrometric Detection: Interlaboratory Study
Authors: Hasnip Sarah , Crews Colin , Potter Nicholas , Brereton Paul , Diserens Henri , Oberson Jean-Marie ,   Collaborators:, Baigrie B , Byrd N , Campbell D J , Diserens H , Hageman L , Hollywood F , Noro Y , Nyman P , Wehage H 
Published: February 2020

Abstract
An interlaboratory study was performed to evaluate the effectiveness of a headspace gas chromatography (GC) method for the determination of 1,3-dichloro-propan-2-ol (1,3-DCP) in soy sauce and related products at levels above 5 ng/g. The test portion is mixed with an internal standard (d5-1,3-DCP) and ammonium sulfate in a sealed headspace vial. After achieving equilibrium, the headspace is sampled either by gas-tight syringe or solid-phase microextraction (SPME) and analyzed by GC with mass spectrometric detection. 1,3-DCP is detected in the selected-ion mode (monitoring m/z 79 and 81 for 1,3-DCP and m/z 82 for the deuterated internal standard) and quantified by measurement against standards. Test materials comprising soy, dark soy, mushroom soy, and teriyaki sauces, both spiked and naturally contaminated, were sent to 9 laboratories in Europe, Japan, and the United States; of these, 5 used SPME and 4 used syringe headspace analysis. Test portions were spiked at 5.0, 10.0, 20.0, 100.0, and 500.0 ng/g. The average recovery for spiked blank samples was 108% (ranging from 96–130%). Based on results for spiked samples (blind pairs at 5, 10, 20, 100, and 500 ng/g) as well as a naturally contaminated sample (split-level pair at 27 and 29 ng/g), the relative standard deviation for repeatability (RSDr) ranged from 2.9–23.2%. The relative standard deviation for reproducibility (RSDR) ranged from 20.9–35.3%, and HorRat values of between 1.0 and 1.6 were obtained.
Liquid Chromatographic Determination of Flumetsulam in Soybeans
Authors: Moawad Michael , Khoo Cheang S 
Published: February 2020

Abstract
A liquid chromatography (LC) method with UV detection is reported for the determination of the sulfonamide herbicide flumetsulam in soybeans. The ground soybean sample was partitioned between methanol and hexane. The hexane removed the lipids, and the methanol layer containing the analyte was further partitioned between dichloromethane and aqueous phosphate buffer at pH 7.0. The aqueous layer, containing the analyte, was acidified to pH 2.2 and partitioned with fresh dichloromethane. The dichloromethane layer containing the analyte was evaporated, and the residue was dissolved in the LC mobile phase for analysis. A polar embedded C18 column was used with a mobile phase of pH 2.2 aqueous phosphate buffer–acetonitrile (68 + 32), run isocratically with detection at 225 nm. The average recovery was 82% with a relative standard deviation (RSD) of 10%. A coefficient of determination of R2 = 0.9992 was achieved for the analyte calibration curve, from 0.005 to 1 μg/mL. The limit of detection, determined from 3 times the standard deviation of 7 replicate extractions of the lowest fortification level (0.01 μg/g, was 0.005 μg/g with an RSD of 22%. LC/electrospray ionization/mass spectrometry in the positive-ion mode was used for identity confirmation of flumetsulam in the fortified soybean extract. The ions at m/z 326, 348, and 129 were observed.
Determination of 22 Triazole Compounds Including Parent Fungicides and Metabolites in Apples, Peaches, Flour, and Water by Liquid Chromatography/TandemMass Spectrometry
Authors: Schermerhorn Patricia G , Golden Paul E , Krynitsky Alexander J , Leimkuehler William M 
Published: February 2020

Abstract
A liquid chromatography/tandem mass spectrometry (LC/MS/MS) method has been developed for the determination of 14 parent triazole fungicides and 8 of their metabolites found in apples, peaches, flour, raw water, and tap water. The triazole fungicides chosen for this multiresidue method development project included propiconazole, fenbuconazole and its RH-9129 and RH-9130 metabolites, cyproconazole, difenoconazole, tebuconazole and its HWG 2061 metabolite, hexaconazole, bromuconazole (both stereoisomers), epoxiconazole, tetraconazole, triticonazole and its RPA-404886 and RPA-406341 metabolites, triadimefon, triadimenol, and myclobutanil. Of special concern to the U.S. Environmental Protection Agency were the metabolites common to all triazole fungicides: free triazole, 1,2,4-triazole (T), and its 2 conjugates: triazolylalanine (TA) and triazolylacetic acid (TAA). These metabolites were the primary focus of this project. All samples we cleaned up by a combination of C18 solid-phase extraction (SPE), mixed-mode cationic SPE, and mixed-mode anionic SPE columns. A triple-stage quadrupole mass spectrometer, equipped with electrospray ionization in the positive-ion mode, was used to determine the compounds of interest. T, TA, and TAA were quantitated using isotopically labeled internal standards (IS), in which the 1,2,4-triazole ring had been synthesized by using 13C and 15N (IS_T, IS_TA, and IS_TAA). These isotopically labeled internal standards were necessary to correct for matrix effects. The T, TA, and TAA metabolites were quantitated at the 25–50 parts-per-billion (ppb) level in food commodities and at 0.50 ppb in water. Recoveries were 70–101% from apples, 60–121% from peaches, 57–118% from flour, 75–99% from raw water, and 79–99% from tap water.
Sample Sizes Needed for Specified Margins of Relative Error in the Estimates of the Repeatability and Reproducibility Standard Deviations
Authors: McClure Foster D , Lee Jung K 
Published: February 2020

Abstract
Sample size formulas are developed to estimate the repeatability and reproducibility standard deviations (sr and sR) such that the actual error in (sr and sR) relative to their respective true values, σr and σR, are at predefined levels. The statistical consequences associated with AOAC INTERNATIONAL required sample size to validate an analytical method are discussed. In addition, formulas to estimate the uncertainties of (sr and sR) were derived and are provided as supporting documentation.Formula for the Number of Replicates Required for a Specified Margin of Relative Error in the Estimate of the Repeatability Standard Deviation
Simultaneous High-Performance Thin-Layer Chromatography Densitometric Assay of Trandolapril and Verapamil in the Combination Preparation
Authors: Kowalczuk Dorota 
Published: February 2020

Abstract
A high-performance thin-layer chromatography (TLC) method coupled with densitometric analysis has been developed for simultaneous measurement of trandolapril (TRA) and verapamil (VER) in 2-component mixtures and in their combination capsules. The active substances were extracted from capsules withmethanol (mean recovery: 103.4% for TRA, 97.13% for VER) and chromatographed on TLC plates coated with silica gel 60 F254 in horizontal chambers with ethyl acetate–ethanol–acetic acid (8 + 2 + 0.5, v/v) mobile phase. Chromatographic separation of these components was followed by ultraviolet densitometric quantification at 215 nm. The calibration graphs were constructed over the concentration range from 0.5 to 1.5 μg/μL (corresponding to 5.0–15.0 μg/spot for both drugswith good correlation (r ≥ 990). Detection and quantitation limits were found to be 1.25 and 3.75 μg/spot for TRA and 0.15 and 0.45 μg/spot for VER, respectively. The proposed method was used for determination of both drugs in TRA-VER capsules with satisfactory precision [0.97% &lt; relative standard deviation (RSD) &lt;4.50% for TRA, 0.49% &lt; RSD &lt; 3.10% for VER] and accuracy [2.16% &lt; relative error (RE) &lt; 4.90% for TRA, 1.73% &lt; RE &lt; 5.68% for VER].
Comparison of the Compact Dry TC Method with the Standard Pour Plate Method (AOAC Official Method 966.23) for Determining Aerobic Colony Counts in Food Samples: Performance-Tested MethodSM
Authors: Kodaka Hidemasa , Mizuochi Shingo , Teramura Hajime , Nirazuka Tadanobu 
Published: February 2020

Abstract
Compact Dry TC qualifies as a rapid method kit for determining aerobic colony counts in foods. The plates are presterilized and contain culture medium and a cold-soluble gelling agent. The medium is rehydrated by inoculating 1 mL diluted sample into the center of the self-diffusible medium and allowing the solution to diffuse by capillary action. The plates can then be incubated and the colonies counted without any additional steps. The Compact Dry TC method was validated with 5 different raw meats. The performance tests were conducted at 35° and 30°C. In all required performance studies, no apparent differences were observed between the Compact Dry TC method and the Standard Pour Plate method (AOAC Official Method 966.23) for the detection level of aerobic microorganisms. For the accuracy claim (n = 60), a correlation factor of r235 = 0.9977 (35°C) and r230 = 0.9932 (30°C) could be assigned, as stated in the application for “Performance Tested Method.SM” Quality consistency and storage robustness studies, showed no significant variations in plate count results with different production lots or plates of diverse storage age.
Determination of Mercury in Carbon Black by Cold Vapor Atomic Absorption Spectrometry
Authors: Hepp Nancy M 
Published: February 2020

Abstract
Recently, a new color additive, D&C Black No. 2, a high-purity furnace black in the general category of carbon blacks, was listed as a color subject to batch certification by the U.S. Food and Drug Administration. Asimple procedure was developed to determine mercury (Hg) in D&C Black No. 2, which is limited by specification to not more than 1 ppm Hg. The method uses partial acid digestion followed by cold vapor atomic absorption and was developed bymodifying a method used for other color additives. The carbon black samples are treated with amixture of nitric and hydrochloric acids and heated by microwave in sealed Teflon&lt;sup/&gt; vessels. The resulting solutions, which are stable to Hg loss for at least 1 week, are diluted and analyzed for Hg using cold vapor atomic absorption spectrometry. Validation was performed by spiking carbon black samples with inorganic Hg (HgNO3) at levels from 0.1 to 1.5 /g, and by analyzing 2 standard reference materials. At the specification level of 1 ppm Hg (1 g Hg/g), the 95% confidence interval was 0.01 ppm Hg (0.01 g Hg/g). The method developed in this study gave good results for very difficult-to-analyze materials, such as coal standard reference materials and carbon black. By eliminating volatility and adsorption factors through the formation of HgCl42 complexes, one can avoid using extremely hazardous acids such as HF and HClO4.
Liquid Chromatographic Determination of N-Methyl Carbamate Pesticide Residues at Low Parts-Per-Billion Levels in Eggs
Authors: Schenck Frank J , Podhorniak Lynda V , Hobbs James , Casanova John , Donoghue Dan 
Published: February 2020

Abstract
A reversed-phase liquid chromatographic (LC) method is presented for the analysis of N-methyl carbamate pesticide residues and piperonyl butoxide in eggs at levels as low as 2 gkg (ppb). The study was undertaken to provide data for dietary exposure estimates used in risk analysis. The method uses an acetonitrile extraction followed by liquidliquid partitioning and normal-phase aminopropyl solid-phase extraction column cleanup. Determination of residues is by reversed-phase LC with an inline postcolumn reaction followed by fluorescence detection. The average recoveries of 21 fortified (most at 2.0 and 20.0 ppb) N-methyl carbamate pesticide residues and the carbamate metabolite 1-naphthol from eggs ranged from 70 to 107%. Recoveries of the pesticide synergist piperonyl butoxide ranged from 63 to 106%. Single-comb White Leghorn hens were treated with the carbamate carbaryl, and the eggs subsequently produced were analyzed for carbaryl and 1-naphthol residues.
Determination of Coenzyme Q10 in Over-the-Counter Dietary Supplements by High-Performance Liquid Chromatography with Coulometric Detection
Authors: Tang Peter H 
Published: February 2020

Abstract
A rapid and sensitive method is described for the determination of coenzyme Q10 (Q10) in over-the-counter dietary supplements by automated high-performance liquid chromatography (HPLC) with coulometric detection. Sample solutions of powder-filled capsules, oil-based softgels, and tablets were prepared by serial dilution with 1-propanol. After dilution, a known volume of sample solution containing Q10 and the internal standard, coenzyme Q9 (Q9), was directly injected into the HPLC system. Most of electrochemically active compounds in the injection were oxidized at the precolumn conditioning cell and postcolumn guard cell. Q9 and Q10 were monitored at an analytical cell that contained 2 coulometric electrodes, where Q9 and Q10 were reduced to the corresponding ubiquinol-9 and -10 and then oxidized to produce currents. This method produced a linear detector response for peak height measurements over the concentration range of 0.058 g/mL (r &gt; 0.999). The lower limit of detection was 5 ng/mL (signal-to-noise ratio, 3). The mean recovery was 98.9 0.6%; coefficients of variation for intra- and interday precisions were 1.84.0%. The proposed method was successfully applied to the determination of Q10 in marketed products.
A Simple and Rapid High-Performance Liquid Chromatography Method for Determining Furosemide, Hydrochlorothiazide, and Phenol Red: Applicability to Intestinal Permeability Studies
Authors: Valizadeh Hadi , Zakeri-Milani Parvin , Islambulchilar Ziba , Tajerzadeh Hosniyeh 
Published: February 2020

Abstract
A simple reversed-phase high-performance liquid chromatography (HPLC) method with ultraviolet detection at 280 nm was developed for simultaneous quantitation of furosemide and hydrochlorothiazide along with phenol red as a nonabsorbable marker for in situ permeability studies in anaesthetized rats. A jejunal segment of approximately 10 cm was isolated and cannulated in both ends for inlet and outlet solution. The perfusate was collected every 10 min, and samples were analyzed using the developed method. The mobile phase was acetonitrile-watser-triethylamine-glacial acetic acid (41.5 + 57.4 + 0.1 + 0.9, adjusted to pH 5.6) at a flow rate of 1 mL/min; the run time was 9 min. The calibration graphs were linear for all 3 compounds (r &gt; 0.999) across the concentration range of 7.93-125 μg/mL for phenol red and 6.25-100 μg/mL for hydrochlorothiazide and furosemide. The limits f quantitation were 7.2, 8.9, and 6.8 μg/mL for furosemide, hydrochlorothiazide, and phenol red, respectively. The coefficients of variation for intraassay and interassay precision were less than or equal to 7.6%, and the accuracy was between 93.2103.4%. Using the single pass intestinal perfusion technique and the suggested HPLC method for sample analysis, mean values of 0.25 10-4(±0.16) cm/s and 0.22 10-4 (±0.13) cm/s were obtained for furosemide and hydrochlorothiazide, respectively.