bluuebunny/crossref_metadata_2025_split huggingface dataset:
LC/MS/MS Study for Identification of Entacapone Degradation Product Obtained by Photodegradation Kinetics
Authors: Paim Clés S , Palma Eduardo C , Malesuik Marcelo D , Steppe Martin 
Published: February 2020

Abstract
Entacapone is indicated for clinical use as an adjunct to levodopa/carbidopa to treat patients with idiopathic Parkinson's Disease who experience the signs and symptoms of end-of-dose wearing-off. The aim of this study was to determine the photodegradation kinetics and to elucidate the structure of the main degradation product. The stability of entacapone was studied in order to investigate the degradation kinetics of this drug using LC as a stability indicator. Entacapone was subjected to accelerated photodegradation. This study was carried out with methanolic solutions, prepared from coated tablets, in quartz cells under UV light at 254 nm. The degradation process of entacapone in solutions can be described by second-order kinetics under the experimental conditions used in this study. The LC/MS/MS determinations revealed that in the above conditions the photodegraded product formed the geometric isomer of entacapone (Z-entacapone). The obtained results show the importance of appropriate light protection during the drug development process, storage, and handling.
Classification of Wines from Five Spanish Origin Denominations by Aromatic Compound Analysis
Authors: Sáenz Cecilia , Cedráenzn Trinidad , Cabredo Susana 
Published: February 2020

Abstract
Wine is a complex matrix in which aroma compounds play an important role in the characterization of the flavor pattern of a given wine. Twelve volatile compounds were determined in 244 samples of Spanish red wines from different denominations of origin: Rioja, Navarra, Valdepeas, La Mancha, and Cariena. The samples were analyzed by GC using headspace solid-phase microextraction. The concentration (mg/mL) intervals obtained were 3-methyl-butyl acetate (3.9 to 116), 3-methyl-1-butanol (93 to 724), ethyl hexanoate (0.8 to 39), 1-hexanol (0.3 to 6.7), ethyl octanoate (1.4 to 41), diethyl succinate (0.2 to 13), 2-phenyl ethyl acetate (0 to 5.3), hexanoic acid (0 to 8.3), geraniol (0 to 3.0), 2-phenylethanol (1.5 to 56), octanoic acid (0 to 20), and decanoic acid (0 to 3.3). Wines were classified by multivariate statistical methods: principal component analysis, and lineal discriminant analysis. A correct differentiation among wines according to their origin was obtained by lineal discriminant analysis.
Theoretical and Experimental Aspects of Microbicidal Activities of Hard Surface Disinfectants: Are Their Label Claims Based on Testing Under Field Conditions?
Authors: Omidbakhsh Navid 
Published: February 2020

Abstract
High-touch environmental surfaces are important in the spread of many nosocomial pathogens. Although such surfaces are routinely disinfected, the testing and label claims of many common disinfectants do not reflect the realities of field use. A study was conducted to determine the influence of several crucial factors on the action of disinfectants in general, and to assess the killing efficiency of selected chemistries against Staphylococcus aureus and Pseudomonas aeruginosa, related to their drying times (i.e., after one application) and label-specified contact times using a quantitative carrier test. The products were also tested for their ability to wet a hydrophobic (epoxy resin) surface. The hard-surface disinfectants (in-use concentration in ppm) tested were: (a) chlorine bleach (500); (b) quaternary ammonium compounds (quat; 600) alone; (c) quat (3000) with 17 isopropanol (v/v); (d) quat (3000) with 60 ethanol (v/v); (e) phenolic (800) alone; (f) quat (2000), phenolic (3000) with 70 ethanol (v/v); and (g) accelerated hydrogen peroxide (AHP; 5000 of H2O2). The arbitrarily set criterion of bactericidal activity was 6 log10 reduction in the viability of both species tested. All surfaces tested with all products dried in &lt;5 min, with alcohol-based surfaces drying significantly faster. Even though the alcohol-free quat and phenolic claim a contact time of 10 min, they dried in &lt;4 min after a single application and failed to meet the performance criterion. Bleach (500 ppm) dried in about 3 min and was effective. AHP also dried in about 3 min and met its label claim even at 1 min of contact. Quat (3000) with 17 isopropanol dried at 1 min and was effective. Quat (3000) with 60 ethanol and quat (2000), phenolic (3000) with 70 ethanol dried in &lt;1 min, and were ineffective. AHP, alcohol-containing quats, and quat-phenolic-alcohol gave acceptable wettability, while quat and phenolic alone, as well as bleach, covered the treated surface unevenly. The findings show that label claims, especially those for contact times, fail to reflect the way many hard-surface disinfectants are used in the field.
Studies on Phytoestrogenic and Nonphytoestrogenic Compounds in Trifolium incarnatum L. and Other Clover Species Using Pressurized Liquid Extraction and High Performance Column Liquid Chromatography with Photodiode-Array and Fluorescence Detection
Authors: Zgórka Grażyna 
Published: February 2020

Abstract
HPLC coupled with photodiode array (PDA) and fluorescence (FL) detectors has been used for the identification and determination of phytoestrogenic (isoflavones and coumestrol) and nonphytoestrogenic (flavones) compounds in hydrolyzed and nonhydrolyzed extracts obtained from aerial parts of Trifolium incarnatum L. and related clover species. The effective isolation technique of pressurized liquid extraction (PLE) was used. Various types of extraction solvents, i.e., ethanol, n-propanol, n-butanol, and water solutions (75%, v/v) of methanol or ethanol at changeable or constant temperatures were tested, taking into account the chemical character of isolated compounds. Higher PLE efficiency in relation to isoflavone aglycones was found for ethanol. Predominant isoflavone glycosides determined in clover samples were sissotrin and ononin, reaching levels above 1.4% dry weight (wt) in T. medium. The presence of flavone compounds (apigenin and luteolin) in aerial parts of T. incarnatum, occurring in amounts exceeding 0.4% dry wt, documented chemotaxonomic distinction of this species from other clovers examined. Additionally, within the group of phytoestrogenic isoflavones, only biochanin A and formononetin derivatives were identified in above-ground parts of T. incarnatum . The application of simultaneous PDA and FL detection enabled unambiguous confirmation of the lack of a strong phytoestrogen, coumestrol, in all hydrolyzed and nonhydrolyzed clover extracts.
Simultaneous Determination of Some Components in Detergent Washing Powder by Mid-Infrared Spectrometry and Artificial Neural Network
Authors: Khanmohammadi Mohammadreza , Garmarudi Amir Bagheri , Rouchi Mohammad Babaei , Khoddami Nafiseh 
Published: February 2020

Abstract
A method has been established for simultaneous determination of sodium sulfate, sodium carbonate, and sodium tripolyphosphate in detergent washing powder samples based on attenuated total reflectance Fourier transform IR spectrometry in the mid-IR spectral region (800–1550 cm−1). Genetic algorithm (GA) wavelength selection followed by feed forward back-propagation artificial neural network (BP-ANN) was the chemometric approach. Root mean square error of prediction for BP-ANN and GA-BP-ANN was 0.0051 and 0.0048, respectively. The proposed method is simple, with no tedious pretreatment step, for simultaneous determination of the above-mentioned components in commercial washing powder samples.
Determination of Operating Characteristic, Retesting, and Testing Amount Probabilities Associated with Testing for the Presence of Salmonella in Foods
Authors: McClure Foster D , Lee Jung K 
Published: February 2020

Abstract
The relatively small perceived probability associated with retesting a food for the presence of Salmonella at low levels is often considered as one of the reasons that a confirmatory or check-analysis tends to disagree in practice with the results of an original test. Given a retesting process where a retest is only performed to confirm an original positive Salmonella test, the probability that both the original and retest will test positive for Salmonella has been traditionally determined by some as the product of the probabilities of a positive Salmonella test for the original and retest samples. When examining the probabilities associated with the retesting process, we found that our results disagreed with those based on intuitions apparently held by others concerning how these probabilities should be calculated. For Salmonella testing, operating characteristic values were computed to demonstrate the protections afforded by the Salmonella sampling plans presented in the U.S. Food and Drug Administration's Bacteriological Analytical Manual and to obtain the probability of a positive Salmonella test. The geometric distribution was examined for possible utility in determining the probabilities associated with testing amounts, i.e., the number of Salmonella tests needed to obtain a positive test.
Gas Chromatographic Determination of Bifenthrin in Technical and Selected Formulated Products: Collaborative Study
Authors: Kikta Edward J ,   Collaborators:, Bennett O O , Bradbury L , Coco P , Henley K , Hernandez A , Larson R , Lew C , Pandey S Y , Podhorniak L , Rains D , Ritland C , Nelson R , Wan P 
Published: February 2020

Abstract
A GC method for the analysis of technical and formulated bifenthrin samples was evaluated in a collaborative study. Bifenthrin is determined by using a 50 (trifluoropropyl)-methylpolysiloxane wide-bore capillary column and flame ionization detector. Ten samples, consisting of four formulations and a technical material were analyzed by 12 collaborators using Youden pairs. The four formulation types included in this study were microemulsion (ME), wettable powder (WP), suspension concentrate (SC), and emulsifiable concentrate (EC). Variability in the analysis of two of the formulation types, SC and EC, was later found to be due to the noncommercial containers used to hold the test samples. Because of this, valid data could not be obtained for the EC and SC. For the two formulations for which valid data could be obtained, ME and WP, and the technical chemical, accuracy and variability results are typical of large data sets. For the technical chemical and the two formulations for which valid data were obtained, Official First Action is recommended.
Determination of Anthocyanins in Cranberry Fruit and Cranberry Fruit Products by High-Performance Liquid Chromatography with Ultraviolet Detection: Single-Laboratory Validation
Authors: Brown Paula N , Shipley Paul R 
Published: February 2020

Abstract
A single-laboratory validation study was conducted on an HPLC method for the detection and quantification of cyanidin-3-O-galactoside (C3Ga), cyanidin-3-O-glucoside (C3Gl), cyanidin-3-O-arabinoside (C3Ar), peonidin-3-O-galactoside (P3Ga), and peonidin-3-O-arabinoside (P3Ar) in cranberry fruit (Vaccinium macrocarpon Aiton) raw material and finished products. An extraction procedure using a combination of sonication and shaking with acidified methanol was optimized for all five anthocyanins in freeze-dried cranberry fruit and finished products (commercial extract powder, juice, and juice cocktail). Final extract solutions were analyzed by HPLC using a C18 RP column. Calibration curves for all anthocyanin concentrations had correlation coefficients (r2) of 99.8. The method detection limits for C3Ga, C3Gl, C3Ar, P3Ga, and P3Ar were estimated to be 0.018, 0.016, 0.006, 0.013, and 0.011 g/mL, respectively. Separation was achieved with a chromatographic run time of 35 min using a binary mobile phase with gradient elution. Quantitative determination performed in triplicate on four test materials on each of 3 days (n 12) resulted in RSDr from 1.77 to 3.31. Analytical range, as defined by the calibration curves, was 0.5736.53 0000000g/mL for C3Ga, 0.159.83 g/mL for C3Gl, 0.2817.67 g/mL for C3Ar, 1.0164.71 g/mL for P3Ga, and 0.4227.14 g/mL for P3Ar. For solid materials prepared by the described method, this translates to 0.063.65 mg/g for C3Ga, 0.020.98 mg/g for C3Gl, 0.031.77 mg/g for C3Ar, 0.106.47 mg/g for P3Ga, and 0.042.71 mg/g for P3Ar.
Monitoring Disopyramide, Lidocaine, and Quinidine by Micellar Liquid Chromatography
Authors: Ochoa-Aranda Enrique , Esteve-Romero Josep , Rambla-Alegre Maria , Martinavarro-Domnguez Adri , Marcos-Toms Jos V , Bose Devasish 
Published: February 2020

Abstract
A micellar liquid chromatography (MLC) method using a C18 column was developed to determine three antiarrhythmic drugsdisopyramide, lidocaine, and quinidinethat are most usually monitored in serum samples. After the application of an interpretative strategy for optimization of sodium dodecyl sulfate (SDS) and modifier concentrations in order to ensure the minimum analysis time, maximum sensitivity, and good resolution, the optimum chromatographic conditions for the determination of the three antiarrhythmics were flow rate, 1 mL/min; injection volume, 20 L; separation temperature, 25C; mobile phase, 150 mmol/L SDS-7 (v/v) butanolphosphate buffer, 10 mmol/L, pH 70.9 (w/v) NaCl; and detection at 214 nm. The calibration curves for the drugs were linear (r2 &gt; 0.999). The intraday and interday precisions were lower than 3.9 (CV). Recoveries were 100 0.6 when the method was applied to both serum samples spiked with the antiarrhythmics (n 10) and real serum samples. In all cases, the results were similar to those obtained using the reference method (fluorescence polarization immunoassay) usually used in the Spanish hospital. The proposed method is useful for hospital monitoring of the antiarrhythmics by direct injection into the chromatograph.
Validated Stability-Indicating HPLC Method for Paricalcitol in Pharmaceutical Dosage Form According to ICH Guidelines: Application to Stability Studies
Authors: Ortega Raquel , Navas Natalia , Salmerón Antonio , Cabeza José , Capitán-Vallvey Luís F 
Published: February 2020

Abstract
A stability-indicating HPLC method with diode array detection for the determination of paricalcitol, a synthetic vitamin D2 analog, was developed. Analytical parameters were studied according to International Conference on Harmonization guidelines. A C18 column (250 4.6 mm, 5 m particle size) maintained at 25C was used as the stationary phase, and acetonitrilewater (70 30, v/v) as the mobile phase. Chromatograms were recorded at 250 nm. In forced degradation studies, the effects of acid, base, oxidation, temperature, and UV light were investigated and showed no interference with the drug peak. The method was found to be linear (r 0.9989) at concentrations ranging from 0.6 to 10.0 mg/L paricalcitol, precise (repeatability and intermediate precision estimated as RSD less than 3.5), accurate (recoveries higher than 95), specific, and robust. The LOD and LOQ were 0.6 and 0.2 mg/L, respectively. The validated method was used for paricalcitol determination in a formal stability study of its pharmaceutical dosage form in preloaded syringes. The stability of a diluted solution of its pharmaceutical form in Viaflo bags was also tested. The results showed that paricalcitol was stable in preloaded syringes during a period of 30 days from preparation in the different storage conditions tested (room temperature without protection from daylight and 4.4C with protection from daylight). On the contrary, paricalcitol was quickly lost when stored in Viaflo bags by adsorption onto the walls of the container.
Determination of Pesticide Residues in Honey by Single-Drop Microextraction and Gas Chromatography
Authors: Tsiropoulos Nikolaos G , Amvrazi Elpiniki G 
Published: February 2020

Abstract
A novel, simple, and rapid single-drop microextraction (SDME) procedure combined with GC has been developed, validated, and applied for the determination of multiclass pesticide residues in honey samples. The SDME was optimized using a Plackett-Burman screening design considering all parameters that may influence an SDME procedure and a consequent central composite design to control the parameters that were found to significantly influence the pesticide determination. The developed analytical method required minimal volumes of organic solvents and exhibited good analytical characteristics with enrichment factors ranging from 3 for -endosulfan to 10 for lindane, procymidone, and captan and method quantification limits ranging from 0.03 g/kg for phosalone to 10.6 g/kg for diazinon. The relative recoveries obtained ranged from 70.8 for captan to 120 for fenarimol, and the precision (RSD) ranged from 3 to 15. The proposed SDME procedure followed by GC with an electron capture detector for quantification and GC/MS for identification was applied with success to the analysis of 17 honey samples. Monitoring results indicated a low level of honey contamination by diazinon, chlorpyrifosethyl, procymidone, bromopropylate, and endosulfan (-, -, and endosulfan sulfate) residues that were far below the maximum residue limit values specified by the European Union for endosulfan (10 g/kg) and bromopropylate (100 g/kg) in honey samples.
Determination of Lead and Manganese in Biological Samples and Sediment Using Slurry Sampling and Flame Atomic Absorption Spectrometry
Authors: Vieira Daniel Rodrigues , Castro Jacira Teixeira , Lemos Valfredo Azevedo 
Published: February 2020

Abstract
A procedure was developed for the determination of lead (Pb) and manganese (Mn) using slurry sampling. The two elements were detected using flame atomic absorption spectrometry with a slotted tube atom trap. Slurries were prepared by adding nitric acid solution (0.30, w/v) to a powdered sample (0.10 g). After homogenization by ultrasonic bath for 15 min, the slurries were introduced directly into the detection equipment. Some conditions of the procedure were evaluated, such as acid concentration, presence of surfactants, and sonication time. Under optimized conditions, the LODs and LOQs achieved were 0.8 and 2.6 g/g for Pb and 0.5 and 1.6 g/g for Mn, respectively. The precision obtained varied between 3.1 and 5.8 (Mn), and 2.6 and 5.4 (Pb) for slurries of shrimp and sediment. The analytical curves were established using aqueous standards in nitric acid solutions. The accuracy of the method was assessed through the determination of Pb and Mn in the following certified reference materials: ERM-CE 278 (mussel tissue), CRM 397 (human hair), and SRM 1646a (estuarine sediment). The proposed procedure was successfully applied to the determination of Pb and Mn in six samples of shrimp powder, seasoning, and river sediment. The levels of Mn detected varied from 2.2 to 71.3 g/g; Pb was detected in only one sediment sample (4.3 g/g).
Study and Development of Reversed-Phase HPLC Systems for the Determination of 2-Imidazolines in the Presence of Preservatives in Pharmaceutical Preparations
Authors: Antoniou Constantinos G , Markopoulou Catherine K , Kouskoura Maria G , Koundourellis John E 
Published: February 2020

Abstract
Different HPLC chromatographic systems were investigated on a C18ACE 5 μm, 150 × 4.6 mm id column for the determination of tymazoline, tramazoline, and antazoline, with either naphazoline or xylometazoline, in commercial preparations. For the development and optimization of the systems, a Response Surface Method (r = 0.925–0.980) was used to illustrate the changes in k as a function of pH values and different salt concentrations. The simultaneous separation of 2-imidazolines was accomplished at 40°C with 0.01 M ammonium acetate–methanol (50 + 50, v/v, pH 6.0) mobile phase at a flow rate of 1.2 mL/min. In order to deal with the usual coexistence of 2-imidazolines with benzethonium and benzalkonium chloride preservatives, it was necessary to use another chromatographic system, 0.01 M ammonium acetate–methanol (50 + 50, v/v) mobile phase on a cyano ACE 5 μm, 150 × 4.6 mm id column. As part of a more thorough theoretical investigation, a partial least-squares (PLS) technique was used for modeling the RP-HPLC retention data. The model was based on molecular structure descriptors of the analytes' X variables and on their retention time (Log K) Y. The goodness of fit was estimated by the PLS correlation coefficient (r2) and root mean square error of estimation values, which were 0.994 and 0.0479, respectively.
Liquid Chromatographic Method for the Simultaneous Determination of Eprosartan and Hydrochlorothiazide in Tablets and Human Plasma
Authors: Belal Fathalla , El-Brashy Amina M , El-Enany Nahed , Tolba Manar M 
Published: February 2020

Abstract
A new, specific, and sensitive RP-HPLC method was developed for the simultaneous determination of eprosartan (EPR) and hydrochlorothiazide (HCT). Good chromatographic separation was achieved using a 250 × 4.6 mm id, 5 μm particle size Symmetry® C18 column. The mobile phase acetonitrile–0.1 M phosphate buffer (35 + 65, v/v), pH 4.5, was pumped at a flow rate of 1 mL/min, with UV detection at 275 nm. The method showed good linearity in the ranges of 0.5–50 and 0.1–10 μg/mL, with LOD of 0.06 and 0.02 μg/mL and LOQ of 0.20 and 0.08 μg/mL for EPR and HCT, respectively. The proposed method was successfully applied for the analysis of the studied drugs in their synthetic mixture and co-formulated tablets. The method was further extended to the in vitro and in vivo determination of the two drugs in spiked and real human plasma. Interference likely to be encountered from the co-administered drugs was studied.
DuPont Qualicon BAX® System Assay for Genus Listeria 24E
Authors: Wallace F Morgan , Fallon Dawn , DeMarco Daniel , Varkey Stephen 
Published: February 2020

Abstract
The new BAX® System PCR Assay for Genus Listeria 24E was evaluated for detecting Listeria spp. in frankfurters, spinach, cooked shrimp, queso fresco cheese, and on stainless steel surfaces with a single-stage enrichment in BAX System 24 Listeria Enrichment Broth (24 LEB). Method comparison studies performed on samples with low-level inoculates showed that the BAX System demonstrates a sensitivity equivalent or superior to the U.S. Food and Drug Administration's Bacteriological Analytical Manual and the U.S. Department of Agriculture-Food Safety and Inspection Service culture methods, but with a significantly shorter time to result. Tests to evaluate inclusivity and exclusivity returned no false-negative and no false-positive results on a diverse panel of isolates, and tests for lot-to-lot variability and tablet stability demonstrated consistent performance. Ruggedness studies determined that none of the factors examined, within the range of deviations from specified parameters examined, affect the performance of the assay.
Flame Atomic Absorption Determination of Trace Amounts of Cadmium After Preconcentration Using a Thiol-Containing Task-Specific Ionic Liquid
Authors: Mohamadi Maryam , Mostafavi Ali 
Published: February 2020

Abstract
Dispersive liquid–liquid microextraction (DLLME) based on a task-specific ionic liquid (TSIL) was developed for the extraction and preconcentration of trace amounts of cadmium from aqueous samples, followed by flame atomic absorption spectrometry (FAAS) determination. In the proposed approach, cadmium ions are extracted from aqueous samples using small volumes of trioctylmethylammonium thiosalicylate (TOMATS) dissolved in acetone. TOMATS is a thiol-containing TSIL that can form metal thiolate complexes due to the chelating effect of the ortho-positioned carboxylate group relative to the thiol functionality. The main parameters affecting the performance of DLLME based on TSIL, such as pH, amount of TOMATS, extraction time, injection volume, salt addition, and centrifugation time, were optimized. Under optimum conditions, an LOD of 1.16 ng/mL and a good RSD of 1.8% at 60.0 ng/mL were obtained (n = 7). The proposed method was applied to tap water, wastewater, well water, and milk samples. The results showed that DLLME based on TSIL combined with FAAS is a rapid, simple, sensitive, selective, low cost, volatile organic solvent-free, and efficient analytical method for the separation and determination of trace amounts of cadmium ions.