bluuebunny/crossref_metadata_2025_split huggingface dataset:
Trace Element Profile of a Wild Edible Mushroom (Suillus granulatus)
Authors: Arce Silvia , Cerutti Soledad , Olsina Roberto , Gomez Mara R , Martnez Luis D 
Published: February 2020

Abstract
Seventeen elements, Al, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, P, Pb, V, and Zn (macroelements and trace elements) were investigated by Atomic Spectrometries on a particular wild edible mushroom collected in the central region of Argentina during 2 different years in the same season. The metal content profile in Suillus granulatus samples is given. The found quantities of Na, K, Ca, Mg, Fe, P, V, and Al were 0.40, 10.84, 0.48, 0.30, 0.57, 4.24, 0.18, and 1.23 g/kg dry weight, respectively. The levels of Li, Cu, Zn, Cd, Co, Ni, Cr, and Mn were 0.98, 23.02, 22.30, 0.26, 0.16, 1.17, 0.90, and 28.75 mg/kg dry weight, respectively. Pb was not detected at the investigated levels. The results indicate that the levels of metals in the analyzed samples are not considered to be a health risk. In order to demonstrate the validity of our method, a recovery study was performed with acceptable results.
A Rapid and Easy Multiresidue Method for the Determination of Pesticide Residues in Vegetables, Fruits, and Cereals Using Liquid Chromatography/Tandem Mass Spectrometry
Authors: Takatori Satoshi , Okihashi Masahiro , Okamoto You , Kitagawa Yoko , Kakimoto Sachiko , Murata Hiroshi , Sumimoto Tatsuo , Tanaka Yukio 
Published: February 2020

Abstract
The applicability of a rapid and easy multiresidue method for determination of pesticide residues in agricultural products by using liquid chromatography/tandem mass spectrometry (LC/MS/MS) was examined. Pesticide residues were extracted with acetonitrile in a disposable tube using a homogenizer, followed by salting out with anhydrous magnesium sulfate and sodium chloride. The extract was purified with a double-layered cartridge column (graphite carbon black/primary-secondary amine silica gel). After removal of the solvent, the extract was resolved in methanolwater and analyzed with LC/MS/MS. Recovery tests of 99 pesticide residues from 7 agricultural products were performed at 20 and 100 ng/g. Throughout all of the agricultural products tested, 47 pesticides exhibited satisfactory recoveries (70120) and relative standard deviations (&lt;20) at both concentrations. The time for processing of 12 samples to test solutions was approximately 23 h. This method could be useful for determination of pesticide residues in agricultural products.
An Isocratic Reversed-Phase High-Performance Liquid Chromatographic Method for the Simultaneous Determination of Benzoyl Peroxide and the Related Compounds Benzoic Acid, Benzaldehyde, Ethyl Benzoate, Methylparaben, and Propylparaben in Dermal Preparations
Authors: Ali Mohammed Shahid , Rafiuddin Syed , Munir Muhammad Imran , Ghori Mohsin , Khatri Aamer Roshanali 
Published: February 2020

Abstract
A reversed-phase high-performance liquid chromatographic method was developed for the simultaneous determination of benzoyl peroxide and the related compounds benzoic acid (BA), methylparaben, benzaldehyde, propylparaben, and ethyl benzoate. The compounds are separated on a column containing octadecyl silane chemically bonded to porous silica particles. The mobile phase is acetonitrilebuffer (45 + 55, v/v). Solutions are injected into the chromatographic system under isocratic conditions at a constant flow rate of 1.5 mL/min with UV detection at 235 nm. Analysis of stability samples showed rapid accumulation of BA by thermal degradation. A rationale has been established for the acceptable limit of BA in the formulation, which already contains BA (0.2) as a preservative. The proposed method is efficient and determines the active compound and 5 related compounds in a run time of 20 min. The method was validated according to the guidelines of the International Conference on Harmonization and demonstrated good agreement with the validation requirements.
Nonextractive Procedure and Precolumn Derivatization with 7-Chloro-4-nitrobenzo-2-oxa-1,3-diazole for Trace Determination of Trimetazidine in Plasma by High-Performance Liquid Chromatography with Fluorescence Detection
Authors: Darwish Ibrahim A , Mahmoud Ashraf M , Khalil Nasr Y 
Published: February 2020

Abstract
A highly sensitive high-performance liquid chromatographic method with fluorescence detection has been developed and validated in a single laboratory for the trace determination of trimetazidine (TMZ) in human plasma. Fluoxetine (FLX) was used as the internal standard. TMZ and FLX were isolated from plasma by protein precipitation with acetonitrile and derivatized by heating with 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole in pH 8 borate buffer at 70C for 30 min. Separations were performed in the isocratic mode on a Nucleosil CN column with the mobile phase acetonitrile10 mM sodium acetate buffer (pH 3.5)methanol (47 + 47 + 6, v/v/v) at a flow rate of 1.0 mL/min. The derivatized samples were excited at 470 nm and monitored at an emission wavelength of 530 nm. Under the optimum chromatographic conditions, a linear relationship with a good correlation coefficient (r 0.9997, n 5) was obtained for the peak area ratio of TMZ to FLX and for TMZ concentrations of 1120 ng/mL. The proposed method has the lowest limits of detection and quantitation reported to date for the determination of TMZ in plasma with values of 0.3 and 0.95 ng/mL, respectively. The values for intra- and interassay precision were satisfactory; the relative standard deviations were 4.04. The accuracy of the method was demonstrated; the recoveries of TMZ from spiked human plasma were 98.13102.83 0.24.04. The method has high throughput because of its simple sample preparation procedure and short run time (&lt;10 min). The results demonstrated that the proposed method would have great value when applied in pharmacokinetic studies for TMZ.
Development and Validation of Reversed-Phase Column High-Performance Liquid Chromatographic and First-Derivative UV Spectrophotometric Methods for Estimation of Voriconazole in Oral Suspension Powder
Authors: Prajapati Arun M , Patel Satish A , Patel Natvarlal J , Patel Dipti B , Patel Sejal K 
Published: February 2020

Abstract
This research paper describes validated reversed-phase high-performance column liquid chromatographic (RP-HPLC) and first-derivative UV spectrophotometric methods for the estimation of voriconazole (VOR) in oral suspension powder. The RP-HPLC separation was achieved on Phenomenex C18 column (250 4.6 mm id, 5 m particle size) using wateracetonitrile (40 + 60, v/v; pH adjusted to 4.5 0.02 with acetic acid) as the mobile phase at a flow rate of 1.4 mL/min and ambient temperature. Quantification was achieved with photodiode array detection at 255 nm over the concentration range of 0.11 g/mL with mean recovery of 99.49 0.83 for VOR by the RP-HPLC method. Quantification was achieved with UV detection at 266 nm over the concentration range of 820 g/mL with mean recovery of 99.74 0.664 for VOR by the first-derivative UV spectrophotometric method. These methods are simple, precise, and sensitive, and they are applicable for the determination of VOR in oral suspension powder.
Determination of Pesticides in Water Samples from the Wieprz-Krzna Canal in the czysko-Wodawskie Lake District of Southeastern Poland by Thin-Layer Chromatography with Diode Array Scanning and High-Performance Column Liquid Chromatography with Diode Array Detection
Authors: Tuzimski Tomasz 
Published: February 2020

Abstract
High-performance thin-layer chromatography with diode array scanning (TLC-DAD) and high-performance column liquid chromatography with a diode array detector (HPLC-DAD) were used to screen water samples for pesticides. Atrazine, clofentezine, chlorfenvinphos, hexaflumuron, terbuthylazine, lenacyl, neburon, bitertanol, and metamitron were enriched from canal water samples by solid-phase extraction (SPE) on octadecyl silane (C18)/styrene-divinylbenzene-1, C18, C18 Polar Plus, and cyanopropyl (CN) cartridges. Recovery rates were high for all extraction materials except CN, for which values for all pesticides were lower. SPE was used for both preconcentration and fractionation of the analytes. Analytes were eluted by means of methanol and dichloromethane. Methanol eluates were analyzed by HPLC-DAD and dichloromethane eluates by TLC-DAD. The method was validated for precision, repeatability, and accuracy. Calibration graphs were linear between 0.1 and 50.0 g/mL for all pesticides, and correlation coefficient (r) values were between 0.9994 and 1.000 as determined by HPLC-DAD. Calibration graphs were linear between 0.1 and 1.5 g/spot for all pesticides, and r values were between 0.9899 and 0.9987 as determined by TLC-DAD. The limit of detection was between 0.04 and 0.23 g/spot for TLC-DAD and 0.02 and 0.45 g/mL for HPLC-DAD.
Analysis of Brain Lipids by Directly Coupled Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry and High-Performance Thin-Layer Chromatography
Authors: Fuchs Beate , Nimptsch Ariane , Süß, Rosmarie , Schiller Jürgen 
Published: February 2020

Abstract
Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) is a soft ionization MS technique providing only minor fragmentation of the analyte. Therefore, the method is basically suitable for mixture analysis, although the ion yields strongly depend on the basicity/acidity of the analyte in relation to the applied matrix. Accordingly, less sensitively detectable compounds may be suppressed by more sensitively detectable compounds. Thus, separation of the mixture into the individual compounds is normally indispensable. This paper demonstrates the capabilities and limitations of a direct, simple, and inexpensive MALDI-high-performance thin-layer chromatography (HPTLC) coupling for the analysis of a crude lipid extract from porcine brain. Brain lipids were chosen because they represent a rather complex mixture and are of currently significant research interest. It was found that normal-phase HPTLC-separated lipids can be easily characterized by direct MALDI-TOF-MS analysis with sufficient resolution to allow the assignment of virtually all lipid classes, even rather minor species such as phosphorylated phosphoinositides or complex glycolipids as gangliosides. Advantages and disadvantages of this approach are discussed.
Determination of Plant Hormones in Fertilizers by High-Performance Liquid Chromatography with Photodiode Array Detection: Method Development and Single-Laboratory Validation
Authors: Gambino Grazia Laura , Pagano Pietro , Scordino Monica , Sabatino Leonardo , Scollo Emanuele , Traulo Pasqualino , Gagliano Giacomo 
Published: February 2020

Abstract
A simple and reliable high-performance liquid chromatographic method that uses photodiode array detection was developed for the simultaneous determination of 12 native and synthetic plant hormones, i.e., plant growth regulators (PGRs), in fertilizers, such as 1-naphthol, 2,4-dichlorophenoxyacetic acid, 4-(2,4-dichlorophenoxy)butyric acid, 4-chlorophenoxyacetic acid, indole-3-acetic acid, 4-(3-indolyl)butyric acid, dichlorprop, (4-chloro-2-methylphenoxy)acetic acid, -naphthaleneacetic acid, 1-naphthaleneacetamide, -naphthoxyacetic acid, and thidiazuron. The method was experimentally validated for routine regulatory application, and the following analytical parameters were assessed for all PGRs studied: linearity; specificity; precision (relative standard deviation) and accuracy, both measured at 3 concentration levels (0.1, 0.05, and 0.01, w/w); ruggedness; limit of detection; and limit of quantification. Results were satisfactory for all method validation parameters tested and for all PGRs studied, demonstrating the suitability of the method for the determination of PGRs in fertilizers. The uncertainty of measurement was also estimated at 3 concentration levels for all PGRs by using the approach of the International Organization for Standardization, described in its Guide to the Expression of Uncertainty in Measurement. The method was applied to 20 samples of liquid fertilizer with declared biostimulant properties.
Comparison of Refluxing, Ultrasonic- and Microwave-Assisted Extraction of Dihydromyricetin from Ampelopsis grossedentata
Authors: Li Hui , Li Yanan , Zhang Yongkang , Shi Hui , Hu Wenbin , Zhang Zhaohui 
Published: February 2020

Abstract
Three techniquesrefluxing extraction (RE), ultrasonic-assisted extraction (UAE), microwave-assisted extraction (MAE)for extraction of dihydromyricetin from Ampelopsis grossedentata, family Vitaceae, were evaluated. A 70 methanolwater solution was used as extraction solvent, and extracts obtained were analyzed by high-performance liquid chromatography (HPLC). Results showed that the MAE method was the most efficient in the shortest time, followed by RE and UAE. Maximum extraction efficiency of dihydromyricetin was obtained by using the MAE technique, which needs only 10 min, whereas UAE and RE require 40 and 300 min, respectively, to gain higher extraction efficiency of dihydromyricetin. The time needed for MAE was 30 times less than that needed for RE. Extracts obtained by using different methods were shown by HPLC analysis to possess similar chemical constituents, and extraction reproducibility was satisfactory for these techniques. Compared with UAE and RE, the MAE is a better alternative extraction technique for large-scale speedy extraction of dihydromyricetin from this plant.
Simultaneous Determination of Some Phenothiazine Derivatives in Human Blood by Headspace Solid-Phase Microextraction and Gas Chromatography with Nitrogen-Phosphorus Detection
Authors: Shinmen Natsuko , Lee Xiao-Pen , Kumazawa Takeshi , Hasegawa Chika , Ishiwata Yasuhiro , Sato Keizo , Seno Hiroshi , Suzuki Osamu 
Published: February 2020

Abstract
Chlorpromazine, levomepromazine, promazine, triflupromazine, and trimeprazine were simultaneously determined in human whole blood and plasma by combining headspace solid-phase microextraction and gas chromatography with nitrogenphosphorus detection. Extraction efficiency for the phenothiazine derivatives was 0.0130.117 for both sample types. Regression equations were linear [correlation coefficient (r) 0.99510.9999] within the range 2.5200 ng/0.5 mL for triflupromazine and trimeprazine, and 6.3200 ng/0.5 mL for chlorpromazine, levomepromazine, and promazine. The limit of detection for each compound was 0.23.9 ng/0.5 mL whole blood and plasma. Intraday and interday coefficients of variation for all phenothiazines in both human samples were commonly &lt;15 and 20, respectively. We also report the determination of levomepromazine in human plasma after oral administration.
Solid-Phase Microextraction for the Determination of Volatile Compounds in the Spoilage of Raw Ground Beef
Authors: Pérez Rosa Ana , Rojo Maria Dolores , Gonzlez Gema , Lorenzo Cristina De 
Published: February 2020

Abstract
A method using solid-phase microextraction (SPME) and gas chromatography/mass spectrometry was developed and applied to the determination of volatile compounds generated in meat, at different times, from ground beef stored under refrigeration. Selection of the extractive fiber, extraction time, and headspace (HS) or direct extraction was optimized for the determination of volatile compounds from ground meat. Various fibers were investigated, and carboxen/polydimethylsiloxane was selected for these analyses. The HS analysis of the solid sample by HS-SPME produced a higher volatile signal than did direct-SPME. The meat samples were stored under refrigeration and analyzed after 0, 3, and 6 days of storage. These analyses at different times showed important changes in the volatile profile of the evaluated samples. The ketones 3-hydroxy-2-butanone and 2,3-butanedione, and the alcohol 3-methyl-1-butanol were the most representative compounds generated during the meat storage. In general, compounds associated with a butter off-flavor were detected during the storage of raw ground beef.
Quantitative Identification of Pesticides as Target Compounds and Unknowns by Spectral Deconvolution of Gas Chromatographic/Mass Spectrometric Data
Authors: Robbat Albert , Hoffmann Andreas , Namara Kevin Mac , Huang Yongli 
Published: February 2020

Abstract
The results of gas chromatography/mass spectrometry (MS), with Ion Signature Technology, Inc. (North Smithfield, RI) quantitative deconvolution software, are discussed for pesticides identified both as target compounds by using retention and MS data and as unknowns by using only mass spectra. Target compound analysis of 32 pesticides, surrogates, and an internal standard added to lemon oil over a wide concentration range produced precision and accuracy that are well within the acceptable criteria of 25 and 50 for complex samples. When 112 pesticides were added to orange oil and searched as unknowns, 110 of the 112 compounds were correctly identified, with an average pesticide recovery of 101 19. The injection volume of the orange oil fortified with pesticides was selected so that 4 ng per compound was injected on column. No false negatives were found, because ion signals for the 2 unidentified pesticides were not acquired by the instrument in either the standard mixture or the oil. No false positives were detected, although &gt;750 widely different compounds were included in the library search.
A New Method for Application of the Water-Soluble Dye SPADNS in a Carbon Paste Electrode for Determination of Trace Amounts of Copper
Authors: Rohani Tahereh , Taher Mohammad Ali 
Published: February 2020

Abstract
2-(P-sulfophenylazo)-1,8-dihydroxy-3,6-naphthalene disulfate (SPADNS) was adsorbed on surfactant modified zeolite type A by electrostatic interaction in the aqueous phase. The dye was strongly retained and not easily leached from the surfactant-modified zeolite matrix. This compound was incorporated into a carbon paste electrode for anodic stripping voltammetric determination of trace amounts of copper. The calibration plot was linear over the copper concentration range 2.0800 g/L. The detection limit was found to be 0.4 g/L Cu(II), and for 5 successive determinations of 50 and 150 g/L Cu(II) the relative standard deviations were 1.6 and 1.2, respectively. The modified electrode prepared in this study could be used for the determination of Cu(II) in water samples and human hair with good results.
Extraction of Aucubin from Seeds of Eucommia ulmoides Oliv. Using Supercritical Carbon Dioxide
Authors: Li Hui , Hu Jiangyu , Ouyang Hui , Li Yanan , Shi Hui , Ma Chengjin , Zhang Yongkang 
Published: February 2020

Abstract
Supercritical CO2 was used as solvent for the extraction of aucubin from the seeds of Eucommia ulmoides Oliv. The co-solvent composition was tested and extraction conditions were optimized. Results showed that the best co-solvent was a waterethanol mixture (1 + 3, v/v), and the highest yield was obtained when the extraction was performed under 26 MPa at extraction and separation temperatures of 55 and 30C for 120 min, using 6 mL co-solvent/g material at a CO2 flow rate of 20 L/h. In a comparison of the supercritical CO2 and Soxhlet extraction methods, the Soxhlet method needed 3 h to extract 10 g material, whereas the supercritical CO2 extraction technique needed only 2 h to extract 100 g material, thus showing a high extraction capability. The supercritical CO2 extraction produced a higher yield, with a lower cost for the extraction. Owing to the advantages of low extraction temperature, high yield, and ease of separating the product from the solvent, supercritical CO2 extraction is likely to be developed into an ideal technique for the extraction of aucubin, a compound with thermal instability, from the seeds of this plant.
Development and Validation of a Column High-Performance Liquid Chromatographic Method for Determination of Sibutramine in Capsules
Authors: Diefenbach Isabel Cristina Fração , Friedrich Milene , Santos Marcos Roberto Dos , Bittencourt Celso Figueiredo 
Published: February 2020

Abstract
The development and validation of a reversed-phase liquid chromatographic (LC) method for the determination of sibutramine hydrochloride monohydrate in capsules is described. An isocratic LC analysis was performed on a reversed-phase RP-18 column (250 4.6 mm id, 5 m particle size). The mobile phase consisted of methanolwatertriethylamine (80 + 20 + 0.5, v/v/v), with pH adjusted to 5.65 with 85 phosphoric acid, and was pumped at a constant flow rate of 1.0 mL/min. Measurements were made at a wavelength of 223 nm. The calibration curve was linear over the range of 1540 g/mL [correlation coefficient (r2) = 0.9998]. The relative standard deviation (RSD) value for intraday precision was 0.84. The RSD value for interday precision was 0.90. Recoveries ranged from 99.64 to 100.66. No interferences from the excipients were observed. Because of its simplicity and accuracy, the method is suitable for routine quality control analysis of sibutramine in capsules.
Evaluation of Modified PCR Quantitation of Genetically Modified Maize and Soybean Using Reference Molecules: Interlaboratory Study
Authors: Kodama Takashi , Kuribara Hideo , Minegishi Yasutaka , Futo Satoshi , Watai Masatoshi , Sawada Chihiro , Watanabe Takahiro , Akiyama Hiroshi , Maitani Tamio , Teshima Reiko , Furui Satoshi , Hino Akihiro , Kitta Kazumi 
Published: February 2020

Abstract
Real-time polymerase chain reaction (PCR)-based quantitative methods were previously developed and validated for genetically modified (GM) maize or soy. In this study, the quantification step of the validated methods was modified, and an interlaboratory study was conducted. The modification included the introduction of the PCR system SSIIb 3 instead of SSIIb 1 for the detection of the taxon-specific sequence of maize, as well as the adoption of colE1 as a carrier included in a reference plasmid solution as a replacement for salmon testis. The interlaboratory study was conducted with the ABI PRISM&lt;sup/&gt; 7700 and consisted of 2 separate stages: (1) the measurement of conversion factor (Cf) value, which is the ratio of recombinant DNA (r-DNA) sequence to taxon-specific sequence in each genuine GM seed, and (2) the quantification of blind samples. Additionally, Cf values of other instruments, such as the ABI PRISM 7900 and the ABI PRISM 7000, were measured in a multilaboratory trial. After outlier laboratories were eliminated, the repeatability and reproducibility for 5.0 samples were &lt;15.8 and 20.6, respectively. The quantitation limits of these methods were 0.5 for Bt11, T25, and MON810, and 0.1 for GA21, Event176, and RR soy. The quantitation limits, trueness, and precision of the current modified methods were equivalent to those of the previous methods. Therefore, it was concluded that the modified methods would be a suitable replacement for the validated methods.