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https://www.readbyqxmd.com/read/28937880/detection-of-free-microcystins-in-the-liver-and-muscle-of-freshwater-fish-by-liquid-chromatography-tandem-mass-spectrometry
#1
Xiaobin Hu, Jinyun Ye, Rongfei Zhang, Xiang Wu, Yixiang Zhang, Chenglong Wu
MC analysis of biological tissue is considered to be very difficult due to the lack of validated methods. This is the primary limiting factor for monitoring potential risks in both the flesh of aquatic organisms and the aquatic ecosystem. In this study, an effective method to determine free MCs (MC-LR and MC-RR) in the muscle and liver tissues of freshwater cultured fish was developed using solid-phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC/MS-MS). The extraction solvent, time of extraction, eluent and purification of the extract were optimized...
September 22, 2017: Journal of Environmental Science and Health. Part. B, Pesticides, Food Contaminants, and Agricultural Wastes
https://www.readbyqxmd.com/read/28936842/-rapid-analysis-on-chemical-constituents-in-yinyanghuo-zonghuangtong-capsule-by-uplc-q-tof-ms-ms
#2
Xue-E Yu, Jian-Ping Qin, Jia-Chun Li, Wen-Zhe Huang, Zhen-Zhong Wang, Wei Xiao
To analyze and identify the chemical constituents from Yinyanghuo Zonghuangtong capsule by using UPLC/Q-TOF-MS/MS. Chromatographic separation was carried out on an Agilent SB-C₁₈ column (2.1 mm×100 mm, 1.8 μm) at the temperature of 30 ℃. The mobile phase was 0.1% formic acid and acetonitrile by gradient elution, with a flow rate at 0.30 mL•min⁻¹, and the injection volume of 2 μL. The MS spectrum was acquired in both negative and positive ion modes using ESI ion source. Based on relative accurate molecular weight, secondary mass spectrometry pyrolysis fragments and chromatographic peak retention time, as well as fragmentation regularity summarized from reference substance and the literature, we could effectively identify the chemical structure of the components under test...
December 2016: Zhongguo Zhong Yao za Zhi, Zhongguo Zhongyao Zazhi, China Journal of Chinese Materia Medica
https://www.readbyqxmd.com/read/28934681/simultaneous-determination-of-gentiopicroside-and-its-two-active-metabolites-in-rat-plasma-by-lc-ms-ms-and-its-application-in-pharmacokinetic-studies
#3
Kai Xiong, Tingting Gao, Tong Zhang, Zhengtao Wang, Han Han
Gentiopicroside is a natural secoiridoid glycoside that may require metabolic activation to exert pharmacological effects. In this study, two active metabolites of gentiopicroside (M1 and M2) were isolated from rat urines and identified with our previous method. Most importantly, a fast, sensitive and selective ultra high-performance liquid chromatography-tandem mass spectrometry method was developed to simultaneously determine gentiopicroside and its two metabolites in rat plasma. The analytes and internal standard (swertiamarin) were separated on an ACQUITY UPLC(®) BEH C18 column (2...
September 14, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/28934012/liquid-chromatography-tandem-mass-spectrometry-method-for-simultaneous-quantification-of-azoxystrobin-and-its-metabolites-azoxystrobin-free-acid-and-2-hydroxybenzonitrile-in-greenhouse-grown-lettuce
#4
Maheswor Gautam, Inge S Fomsgaard
Lettuce is an important part of the diet in Europe. The permitted levels of pesticides in lettuce are strictly regulated and there is growing urge among food safety authorities to analyse pesticide metabolites as well. Azoxystrobin is one of pesticides that is frequently detected in lettuce. Although there are several analytical methods for the determination of azoxystrobin in lettuce, a sensitive method for the determination of its metabolites in lettuce is lacking. This study aimed at developing an extraction and LC-MS/MS method for the simultaneous determination of azoxystrobin, and its metabolites azoxystrobin free acid and 2-hydroxybenzonitrile in lettuce...
September 21, 2017: Food Additives & Contaminants. Part A, Chemistry, Analysis, Control, Exposure & Risk Assessment
https://www.readbyqxmd.com/read/28929685/-simultaneous-determination-of-8-main-compounds-in-eclipta-herba-by-uplc
#5
Xue-Feng Hou, Shuai Sun, Gang Wang, Hui-Hui Qiu, Shu-Min Ding, Ying Liu, Dan Liu, Liang Feng, Xiao-Bin Jia
To establish an UPLC method for the simultaneous determination of 8 compounds in Eclipta Herba, such as isoquercitrin, luteoloside, demethylwedelolactone, isochlorogenic acid A, isochlorogenic acid C, luteolin, wedelolactone and apigenin. The experiment was performed with a Waters Acquity UPLC BEH C₁₈ (2.1 mm×100 mm, 1.7 μm) column by gradient elution of 0.1% formic acid in water and acetonitrile: 0-4 min,10%-13% A; 4-10 min, 13%-16% A; 10-13 min, 16%-25% A; 13-17 min, 25%-28% A; 17-20 min,28%-40% A;20-25 min,40%-95% A...
November 2016: Zhongguo Zhong Yao za Zhi, Zhongguo Zhongyao Zazhi, China Journal of Chinese Materia Medica
https://www.readbyqxmd.com/read/28929664/-metabolism-of-paeoniflorin-by-rat-intestinal-flora-in-vitro
#6
Zhong-Cheng Ke, Nan Yang, Xue-Feng Hou, Ai-Dong Wang, Liang Feng, Xiao-Bin Jia
In order to clarify the effect of intestinal flora on the absorption and metabolism of paeoniflorin in vivo, the metabolism of paeoniflorin by rat intestinal flora was studied under the in vitro anaerobic condition. Paeoniflorin was incubated with rat anaerobic intestinal flora for 48 h, and UPLC was used to detect the changes of paeoniflorin at different incubation time points under the following chromatographic conditions:WelchromTM C₁₈ chromatographic column (4.6 mm×100 mm, 5 μm), with 0.1% formic acid(A)-acetonitrile(B) as the mobile phase for gradient elution...
October 2016: Zhongguo Zhong Yao za Zhi, Zhongguo Zhongyao Zazhi, China Journal of Chinese Materia Medica
https://www.readbyqxmd.com/read/28927165/air-and-surface-sampling-method-for-assessing-exposures-to-quaternary-ammonium-compounds-using-liquid-chromatography-tandem-mass-spectrometry
#7
Ryan F LeBouf, Mohammed Abbas Virji, Anand Ranpara, Aleksandr B Stefaniak
This method was designed for sampling select quaternary ammonium (quat) compounds in air or on surfaces followed by analysis using ultraperformance liquid chromatography tandem mass spectrometry. Target quats were benzethonium chloride, didecyldimethylammonium bromide, benzyldimethyldodecylammonium chloride, benzyldimethyltetradecylammonium chloride, and benzyldimethylhexadecylammonium chloride. For air sampling, polytetrafluoroethylene (PTFE) filters are recommended for 15-min to 24-hour sampling. For surface sampling, Pro-wipe® 880 (PW) media was chosen...
July 1, 2017: Annals of Work Exposures and Health
https://www.readbyqxmd.com/read/28926680/formic-acid-as-a-secondary-substrate-for-succinic-acid-production-by-metabolically-engineered-mannheimia-succiniciproducens
#8
Jung Ho Ahn, Junho Bang, Won Jun Kim, Sang Yup Lee
There has been much effort exerted to reduce one carbon (C1) gas emission to address climate change. As one promising way to more conveniently utilize C1 gas, several technologies have been developed to convert C1 gas into useful chemicals such as formic acid (FA). In this study, systems metabolic engineering was utilized to engineer Mannheimia succiniciproducens to efficiently utilize FA. (13) C isotope analysis of M. succiniciproducens showed that FA could be utilized through formate dehydrogenase (FDH) reaction and/or the reverse reaction of pyruvate formate lyase (PFL)...
September 19, 2017: Biotechnology and Bioengineering
https://www.readbyqxmd.com/read/28922649/determination-of-74-new-psychoactive-substances-in-serum-using-automated-in-line-solid-phase-extraction-liquid-chromatography-tandem-mass-spectrometry
#9
Sabrina Lehmann, Tobias Kieliba, Justus Beike, Mario Thevis, Katja Mercer-Chalmers-Bender
A detailed description is given of the development and validation of a fully automated in-line solid-phase extraction-liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) method capable of detecting 90 central-stimulating new psychoactive substances (NPS) and 5 conventional amphetamine-type stimulants (amphetamine, 3,4-methylenedioxy-methamphetamine (MDMA), 3,4-methylenedioxy-amphetamine (MDA), 3,4-methylenedioxy-N-ethyl-amphetamine (MDEA), methamphetamine) in serum. The aim was to apply the validated method to forensic samples...
September 7, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/28921991/direct-palladium-catalyzed-carbonylative-transformation-of-allylic-alcohols-and-related-derivatives
#10
Fu-Peng Wu, Jin-Bao Peng, Lu-Yang Fu, Xinxin Qi, Xiao-Feng Wu
A direct, palladium-catalyzed, carbonylative transformation of allylic alcohols for the synthesis of β,γ-unsaturated carboxylic acids has been developed. With formic acid as the CO source, various allylic alcohols were conveniently transformed into the corresponding β,γ-unsaturated carboxylic acids with excellent linear and (E)-selectivity. The reaction was performed under mild conditions; toxic CO gas manipulation and high-pressure equipment were avoided in this procedure.
September 18, 2017: Organic Letters
https://www.readbyqxmd.com/read/28920666/a-softoxometalate-k6-5cu-oh-8-5-h2o-7-5-0-5-k3pw12o40-n-n-1348-2024-as-an-efficient-inorganic-material-for-co2-reduction-with-concomitant-water-oxidation
#11
Santu Das, Saurabh Kumar, Somenath Garai, Ramudu Pochamoni, Shounik Paul, Soumyajit Roy
An immediate challenge for chemists is to devise different methods to trap chemical energy using light by reduction of carbon dioxide to a transportable fuel. To reach this goal the major obstacle lies in finding a suitable material that is abundant and possesses catalytic power to effect such reduction reaction and perform this reduction reaction without using any external photosensitizer. Here we report first time a softoxometalate, based on {[K6.5Cu(OH)8.5(H2O)7.5]0.5[K3PW12O40]} metal oxide framework which is stable in reaction condition that effectively performs photochemical CO2 reduction reaction in water with a very high turnover number of 613 and TOF of 47...
September 18, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28918324/simultaneous-determination-and-pharmacokinetic-study-of-twelve-bioactive-compounds-in-rat-plasma-after-intravenous-administration-of-xuebijing-injection-by-uhplc-q-orbitrap-hrms
#12
Lihua Zuo, Qiuyue Zhong, Zhenhui Wang, Zhi Sun, Lin Zhou, Zhuolun Li, Tanye Xu, Yingying Shi, Jinfa Tang, Shuzhang Du, Xiaojian Zhang
Xuebijing injection (XBJ) is a traditional Chinese herbal prescription widely used in the treatment of sepsis. Extensive studies revealed that the major bioactive constituents of XBJ injection, including phenolic acids, flavonoids, monoterpene glycosides, lactones and organic acids, play an important role in the treatment. In this study, a rapid, sensitive and accurate ultra high performance liquid chromatography - Q Exactive hybrid quadrupole - orbitrap high-resolution accurate mass spectrometry (UHPLC-Q-Orbitrap HRMS) method was developed for simultaneous determination of twelve bioactive compounds in rat plasma after intravenous administration of XBJ injection...
September 8, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28918323/quantitative-determination-of-carfilzomib-in-mouse-plasma-by-liquid-chromatography-tandem-mass-spectrometry-and-its-application-to-a-pharmacokinetic-study
#13
Jee Sun Min, Jiseon Kim, Jung Ho Kim, Doyun Kim, Yu Fen Zheng, Ji Eun Park, Wooin Lee, Soo Kyung Bae
A highly sensitive and rapid LC-MS/MS method was developed and validated to determine the levels of carfilzomib in mice plasma by using chlorpropamide as an internal standard. Carfilzomib and chlorpropamide were extracted from 5 μL of plasma after protein precipitation with acetonitrile. Chromatographic separation was performed on Phenomenex Luna C18 column (50×2.0mm id, 3μm). The mobile phase consisted of 0.1% formic acid in acetonitrile -0.1% formic acid in water (1:1v/v) and the flow rate was 0.3mL/min...
September 1, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28918317/bithionol-residue-analysis-in-animal-derived-food-products-by-an-effective-and-rugged-extraction-method-coupled-with-liquid-chromatography-tandem-mass-spectrometry
#14
Weijia Zheng, Jin-A Park, A M Abd El-Aty, Seong-Kwan Kim, Sang-Hyun Cho, Jeong-Min Choi, Hee Yi, Soo-Min Cho, H A El-Banna, Jae-Han Shim, Byung-Joon Chang, Jing Wang, Jin-Suk Kim, Ho-Chul Shin
Herein, we developed a simple analytical procedure for the quantitation of bithionol residues in animal-derived food products such as porcine muscle, eggs, milk, eel, flatfish, and shrimp using a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction method coupled with liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI(+)/MS-MS). Samples were extracted with 0.1% solution of formic acid in acetonitrile and the extract was purified using a C18 sorbent. Separation was performed on a Waters XBridge™ C18 reversed-phase analytical column using 0...
August 31, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/28917880/intercalated-chitosan-hydroxyapatite-nanocomposites-promising-materials-for-bone-tissue-engineering-applications
#15
Muhammad Anwaar Nazeer, Emel Yilgör, Iskender Yilgör
Preparation and characterization of chitosan/hydroxyapatite (CS/HA) nanocomposites displaying an intercalated structure is reported. Hydroxyapatite was synthesized through sol-gel process. Formic acid was introduced as a new solvent to obtain stable dispersions of nano-sized HA particles in polymer solution. CS/HA dispersions with HA contents of 5, 10 and 20% by weight were prepared. Self-assembling of HA nanoparticles during the drying of the solvent cast films led to the formation of homogeneous CS/HA nanocomposites...
November 1, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28917128/application-of-ultra-high-performance-liquid-chromatography-coupled-with-ltq-orbitrap-mass-spectrometry-for-identification-confirmation-and-quantitation-of-illegal-adulterated-weight-loss-drugs-in-plant-dietary-supplements
#16
Qiaoyuan Cheng, Linjun Shou, Cen Chen, Shi Shi, Minghao Zhou
In this paper, an ultra-high-performance liquid chromatography coupled with linear ion trap quadrupole Orbitrap high resolution mass spectrometry (UHPLC-LTQ-Orbitrap HRMS) method was developed and validated for identification, confirmation and quantitation of illegal adulterated weight-loss drugs in plant dietary supplements. 13 wt-loss drugs were well separated by the gradient elution of 10mmol/L ammonium acetate - 0.05% formic acid H2O and acetonitrile at a flow rate of 0.2mL/min within 12min. The MS analysis was operated under the positive ion and in full MS/dd-MS(2) (data-dependent MS(2)) mode...
September 9, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/28915937/ultra-high-performance-supercritical-fluid-chromatography-mass-spectrometry-procedure-for-analysis-of-monosaccharides-from-plant-gum-binders
#17
Volodymyr Pauk, Tomáš Pluháček, Vladimír Havlíček, Karel Lemr
The ultra-high performance supercritical fluid chromatography-mass spectrometry (UHPSFC/MS) procedure for analysis of native monosaccharides was developed. Chromatographic conditions were investigated to separate a mixture of four hexoses, three pentoses, two deoxyhexoses and two uronic acids. Increasing water content in methanol modifier to 5% and formic acid to 4% improved peak shapes of neutral monosaccharides and allowed complete elution of highly polar uronic acids in a single run. An Acquity HSS C18SB column outperformed other three tested stationary phases (BEH (silica), BEH 2-ethylpyridine, CSH Fluoro-Phenyl) in terms of separation of isomers and analysis time (4...
October 9, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/28903089/simultaneous-determination-of-pentoxifylline-metabolites-m1-lisofylline-m4-and-m5-and-caffeine-in-plasma-and-dried-blood-spots-for-pharmacokinetic-studies-in-preterm-infants-and-neonates
#18
Madhu Page-Sharp, Tobias Strunk, Sam Salman, Julie Hibbert, Sanjay K Patole, Laurens Manning, Kevin T Batty
Advances in bioanalytical methods are facilitating micro-volume and dried blood spot (DBS) analysis of drugs in biological matrices for pharmacokinetic studies in children and neonates. We sought to develop a UPLC-MS/MS assay for simultaneous measurement of caffeine, pentoxifylline (PTX) and three metabolites of PTX in both plasma and DBS. Caffeine, PTX, the metabolites M1 (lisofylline), M4 and M5, and the internal standards (caffeine-d9 and PTX-d6) were separated using a Waters Aquity T3 UPLC C18 column and gradient mobile phase (water-methanol-formic acid)...
August 26, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28902956/the-first-gold-iii-formate-evidence-for-%C3%AE-hydride-elimination
#19
Roopender Kumar, Jean-Philippe Krieger, Enrique Gómez-Bengoa, Thomas Fox, Anthony Linden, Cristina Nevado
The first stable gold(III) formate and experimental evidence for its β-hydride elimination are described. A catalytic dehydrogenation of formic acid together with mechanistic studies shed light on potential pathways operating in fundamental gold-catalyzed transformations.
September 13, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28898719/a-cost-effective-lc-ms-ms-method-for-identification-and-quantification-of-%C3%AE-amanitin-in-rat-plasma-application-to-toxicokinetic-study
#20
Chunlei Li, Fen Wei, Saqib Muhammad, Guangde Yang, Sicen Wang, Xinshe Liu
α-Amanitin is the main lethal component of amanita mushrooms, and data on its toxicokinetics are few. The aim of this study was to develop a sensitive and cost-effective method to identify α-amanitin and investigate its toxicokinetic parameters using liquid chromatography-triple quadrupole tandem mass spectrometry. The colchicine was used as the internal standard (IS). The compounds were extracted from plasma samples by protein precipitation with acetonitrile (containing 1% formic acid). The analysis was performed through multiple reactions monitoring...
September 5, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
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