A rapid and sensitive liquid chromatography-tandem mass spectrometric（LC-MS/MS） assay method has been developed and fully validated for the simultaneous quantification of pravastatin and aspirin in human plasma.Furo...A rapid and sensitive liquid chromatography-tandem mass spectrometric（LC-MS/MS） assay method has been developed and fully validated for the simultaneous quantification of pravastatin and aspirin in human plasma.Furosemide was used as an internal standard.Analytes and the internal standard were extracted from human plasma by liquid-liquid extraction technique using methyl tertiary butyl ether.The reconstituted samples were chromatographed on a Zorbax SB-C;8 column by using a mixture of 5 mM ammonium acetate buffer and acetonitrile（20:80,v/v） as the mobile phase at a flow rate of 0.8 mL/min.The calibration curve obtained was linear（r≥0.99） over the concentration range of 0.50-600.29 ng/mL for pravastatin and 20.07-2012.00 ng/mL for aspirin.Method validation was performed as per FDA guidelines and the results met the acceptance criteria.A run time of 2.0 min for each sample made it possible to analyze more than 400 human plasma samples per day.The proposed method was found to be applicable to clinical studies.展开更多
The lanthanum trivalent ion doped TiO2 nanopowders were prepared by liquid plasma spray with solution of titanium tetra-tert-butoxide and alcohol as feedstock and La(NO3)3·6H2O as doping component. The photocatal...The lanthanum trivalent ion doped TiO2 nanopowders were prepared by liquid plasma spray with solution of titanium tetra-tert-butoxide and alcohol as feedstock and La(NO3)3·6H2O as doping component. The photocatalytic activity of samples at different doping concentrations in photocatalytic degradation of methyl orange was discussed. The powders were characterized by Transmission Electron Microscopy (TEM) and X-Ray Diffraction (XRD), and the effect of doped ion on the pattern, phase composition and crystallite sizes were analyzed. The results indicated that lanthanum trivalent ion doped TiO2 nanopowders could be prepared by liquid plasma spray. Lanthanum trivalent ion doping increased the photocatalytic activity of TiO2 greatly, the optimal doping concentration was 0.5%. The doped powders were the mixture of anatase phase and rutile phase. The contents of anatase phase decreased firstly and then increased with an increase in the contents of lanthanum trivalent ion. Doping lanthanum trivalent ion could make the TiO2 nanopowders uniform and reduced its particle size.展开更多
A novel bioanalytical method was developed and validated for the quantitative determination of darunavir（DRV） in rat plasma by employing hydrophilic interaction chromatography and tandem mass spectrometry（HILIC-MS...A novel bioanalytical method was developed and validated for the quantitative determination of darunavir（DRV） in rat plasma by employing hydrophilic interaction chromatography and tandem mass spectrometry（HILIC-MS/MS） with supported liquid extraction（SLE）.lrbesartan（IRB） was used as an internal standard（IS）.The analyte in rat plasma（200 μL） was isolated through SLE using ethyl acetate as the eluting solvent.The chromatographic separation was achieved on Luna-HILIC（250 mm × 4.6 mm,5 μm）column with a mobile phase of 0.1% of formic acid in water：acetonitrile（5：95,v/v）,at a constant flow rate of 1.0mL/min.The MS/MS ion transitions for DRV（548.1→392.0） and IS（429.2→207.1） were monitored on an ion trap mass spectrometer,operating in the multiple reaction monitoring（MRM） mode.The lower limit of quantitation（LLOQ） was 0.2 ng/mL and quantitation range was 0.2-5000 ng/mL.The method was validated for its selectivity,sensitivity,carryover,linearity,precision,accuracy,recovery,matrix effect and stability.The method was successfully applied to pharmacokinetic study in rats.展开更多
Pd-containing ionic liquid （IL） 1-hexyl-3-methylimidazolium tetrafluoroborate （C6MIMBF4） immobilized on γ-Al2O3 （Pd-IL/γ-Al2O3） was prepared and characterized by Fourier transform infrared spectroscopy （FTIR...Pd-containing ionic liquid （IL） 1-hexyl-3-methylimidazolium tetrafluoroborate （C6MIMBF4） immobilized on γ-Al2O3 （Pd-IL/γ-Al2O3） was prepared and characterized by Fourier transform infrared spectroscopy （FTIR）, scanning electron microscopy （SEM） and Brunauer-Emmett- Teller （BET） analysis. The influences of C6MIMBF4 loading and Pd on methane conversion to C2 hydrocarbons under cold plasma were investigated. FTIR and SEM analyses indicated that C6MIMBF4 had been successfully immobilized on γ-Al2O3 and the C6MIMBF4 showed excellent stability under cold plasma. The results of BET and methane conversion showed that with the increase in immobilization amount of C6MIMBF4 onto γ-Al2O3, the specific surface area and pore volume of IL/γ-Al2O3 decreased, while the selectivity and yield of C2 hydrocarbons increased. The selectivity of C2 hydrocarbons was 94.6% when the loading of C6MIMBF4 was 40%, and the percentage of C2H4 in C2 hydrocarbons was as high as 64% when using Pd-IL/γ-Al2O3 as a catalyst with no conventional thermal reduction treatment. Optical emission spectra （OES） from the cold plasma reactor during methane conversion were also studied. The results indicated that the intensity of the C2, CH, H, and C active species from methane and hydrogen decomposition increased when IL/γ-Al2O3 or Pd-IL/γ-Al2O3 was introduced into the plasma system. Based on the analyses of the gas product and OES spectra, it can be concluded that the surface catalyzed reactions between plasma and ionic liquid were very important for the reduction of Pd2＋ and the formation of C2H4.展开更多
The angular distribution and pressure force of droplets ejected from liquid water and glycerol ablated by nanosecond laser pulses are investigated under different viscosities in laser plasma propulsion. It is shown th...The angular distribution and pressure force of droplets ejected from liquid water and glycerol ablated by nanosecond laser pulses are investigated under different viscosities in laser plasma propulsion. It is shown that with increasing viscosity, the distribution angles present a decrease tendency for two liquids, and the angular distribution of glycerol is smaller than that of water. A smaller distribution leads to a higher pressure force generation. The results indicate that ablation can be controlled by varying the viscosity of liquid propellant in laser plasma propulsion.展开更多
A cold dielectric barrier discharge （DBD） plasma plume with one highly conductive liquid electrode has been developed to treat thermally sensitive materials, and its preliminary discharging characteristics have been...A cold dielectric barrier discharge （DBD） plasma plume with one highly conductive liquid electrode has been developed to treat thermally sensitive materials, and its preliminary discharging characteristics have been studied. The averaged electron temperature and density is estimated to be 0.6eV and 1011/cm3, respectively. The length of plasma plume can reach 5cm with helium gas （He）, and the conductivity of the outer electrode affects the plume length obviously. This plasma plume could be touched by bare hand without causing any burning or painful sensation, which may provide potential application for safe aseptic skin care. Moreover, the oxidative particles （e.g., OH, O＊, 03） in the downstream oxygen （02） gas of the plume have been applied to treat the landfill leachate. The results show that the activated 02 gas can degrade the landfill leachate effectively, and the chemical oxygen demand （COD）, conductivity, biochemical oxygen demand （BOD）, and suspended solid （SS） can be decreased by 52%, 57%, 76% and 92%, respectively.展开更多
A typical quinolones antibiotic ciprofloxacin(CIP) in aqueous solution was degraded by a gas–liquid discharge non-thermal plasma system. The discharge plasma power and the emission intensity of the excited reactive s...A typical quinolones antibiotic ciprofloxacin(CIP) in aqueous solution was degraded by a gas–liquid discharge non-thermal plasma system. The discharge plasma power and the emission intensity of the excited reactive species(RS) generated in the gas phase were detected by the oscilloscope and the optical emission spectroscopy. The effects of various parameters on CIP degradation, i.e. input powers, initial concentrations addition of radical scavengers and p H values were investigated. With the increase of discharge power, the degradation efficiency increased but the energy efficiency significantly reduced. The degradation efficiency also reduced under high concentration of initial CIP conditions due to the competitive reactions between the plasma-induced RS with the degradation intermediates of CIP. Different radical scavengers(isopropanol and CCl_4) on ·OH and H· were added into the reaction system and the oxidation effects of ·OH radicals have been proved with high degradation capacity on CIP.Moreover, the long-term degradation effect on CIP in the plasma-treated aqueous solution proved that the long-lived RS(H_2O_2 and O_3, etc) might play key roles on the stay effect through multiple aqueous reactions leading to production of ·OH. The degradation intermediates were determined by the method of electrospray ionization(+)-mass spectroscopy, and the possible degradation mechanism were presented.展开更多
A simple and sensitive liquid chromatographic method was developed for quantification of cefotetan disodium (CTT),a semi-synthetic cephamycin antibiotic,in human plasma.CTT and the internal standard chloramphenicol we...A simple and sensitive liquid chromatographic method was developed for quantification of cefotetan disodium (CTT),a semi-synthetic cephamycin antibiotic,in human plasma.CTT and the internal standard chloramphenicol were extracted from plasma by a simple one-step protein precipitation with 35% (v/v) perchloric acid.Separation was carried out on a reverse-phase C18 column with a mobile phase of acetonitile-water containing 0.5% (v/v) phosphoric acids (20:80,v/v) at a flow rate of 1.0 mL/min.The column effluent was monitored by UV detection at 300 nm.The column temperature was maintained at 40°C.This method demonstrated good linearity in the range of 0.525-300.0 μg/mL,with correlation coefficients greater than 0.99.The limit of quantification (LOQ) was 0.525 μg/mL in human plasma.Intra-and inter-day precisions were less than 6.63% in terms of relative standard deviation (RSD).The accuracy,when expressed by the bias,ranged from 0.57% to 4.04%.The mean extraction recovery of CTT was higher than 40.94%.The method was found to be precise,accurate,and specific for CTT quantitative analysis,and was successfully applied for a pharmacokinetic study of CTT after a single intravenous dose of 1.0 g of CTT in healthy Chinese subjects.展开更多
Chitosan （CTS） coatings contained calcium （Ca） and phosphorus （P） on titanium （Ti） surface are prepared by the cathode liquid phase plasma technology （CLPT）, in a certain concentration electrolyte solution w...Chitosan （CTS） coatings contained calcium （Ca） and phosphorus （P） on titanium （Ti） surface are prepared by the cathode liquid phase plasma technology （CLPT）, in a certain concentration electrolyte solution with selective additions of ammonium dihydrogen phosphate and calcium nitrate. It is indicated that the parameters for a stable discharge are voltage of 400 V, frequency of 100 Hz, duty cycle of 30% based on a large amount of experiment data. The morphology, structure and composition of the coated samples are studied by SEM, FTIR, XRD, XPS. The results demonstrate that the composite coatings are uniform, and some solid particles of inorganic salt containing calcium and phosphorus dispersed on the coatings. CA tests show that the samples treated by the liquid plasma became less hydrophilic. The variation of hydrophilicity on the CLPT treated titanium is attributed to the change of the function groups on the sample surface. Meanwhile, a possible formation mechanism of the composite coatings is discussed.展开更多
The objectives of this research were to understand the process of converting toluene into phenol in a one-step process directly from a water–toluene mixture using the plasma in-liquid method.Experiments were conducte...The objectives of this research were to understand the process of converting toluene into phenol in a one-step process directly from a water–toluene mixture using the plasma in-liquid method.Experiments were conducted using 27.12 MHz radio frequency（RF） in-liquid plasma to decompose a solution of 30% toluene. Based on the experimental results as evaluated using gas chromatography–mass spectrometry（GC–MS）, along with additional analysis by the Gaussian calculation, density functional theory（DFT） hybrid exchange–correlational functional（B3LYP）and 6-311 G basis, the phenol generated from toluene was quantified including any by-products.In the experiment, it was found that OH radicals from water molecules produced using RF inliquid plasma play a significant role in the chemical reaction with toluene. The experimental results suggest that phenol can be directly produced from a water–toluene mixture. The maximum phenol yields were 0.0013% and 0.0038% for irradiation times of 30s and 60s,respectively, at 120 W.展开更多
Three extraction methods were compared for their efficiency to analyze sitagliptin and simvastatin in rat plasma by LC-MS/MS, including （1） liquid-liquid extraction （LLE）, （2） solid phase extraction （SPE） and ...Three extraction methods were compared for their efficiency to analyze sitagliptin and simvastatin in rat plasma by LC-MS/MS, including （1） liquid-liquid extraction （LLE）, （2） solid phase extraction （SPE） and （3） supported liquid extraction （SLE）. Comparison of recoveries of analytes with different extraction methods revealed that SLE was the best extraction method. The detection was facilitated with ion trap-mass spectrometer by multiple reactions monitoring （MRM） in a positive ion mode with ESI. The transitions monitored were m./z 441.1→325.2 for simvastatin, 408.2→235.1 for sitagliptin and 278.1→260.1 for the IS. The lower limit of quantification （LLOQ） was 0.2 ng/mL for sitagliptin and 0.1 ng/mL for simvastatin. The effective SLE offers enhanced chromatographic selectivity, thus facilitating the potential utility of the method for routine analysis of biological samples along with pharmacokinetic studies.展开更多
This paper aims to explore the effects of a rotating plasma-activated liquid on the dynamic propagation and biomedical application of a helium plasma jet.The spatial distribution of reactive species and the associated...This paper aims to explore the effects of a rotating plasma-activated liquid on the dynamic propagation and biomedical application of a helium plasma jet.The spatial distribution of reactive species and the associated physico-chemical reactions are altered by the rotating liquid,which shows a significant weakening in the axial propagation of the plasma bullet and a strengthening in its radial expansion at the liquid surface.The phenomenon is prompted by the nonzero rotational velocity of the liquid and is regulated by airflow,target distance and liquid permittivity.The concentrations of aqueous reactive species,especially OH and O~-,and the inactivation effectiveness on cancer cells are weakened,indicating that a rotating liquid is not conducive to water treatment of the plasma jet although the treatment area of the plasma jet increases dynamically.This finding is of significance for the plasma–liquid interaction and the biomedical-related applications of plasma jets.展开更多
A rapid and sensitive liquid chromatography tandem mass spectrometry(LC-MS/MS) method has been developed and validated for the determination of moxifloxacin(MOXI) in human plasma. After a simple protein precipitation ...A rapid and sensitive liquid chromatography tandem mass spectrometry(LC-MS/MS) method has been developed and validated for the determination of moxifloxacin(MOXI) in human plasma. After a simple protein precipitation using acetonitrile, the post treatment samples were analysed on a C18 column interfaced with a Triple Quadropole Tandem Mass Spectrometer. Positive electrospray ionization was employed as the ionization source. The mobile phase consisted of 0.1% formic acid–acetonitrile(60:40, v/v). Ciprofloxacin(CIPRO) was used as an internal standard. The analyte and internal standard(CIPRO) were monitored in the multiple reaction monitoring mode(MRM). The mass transition ion-pair has been followed as m/z 402→358.2 for MOXI and 332→288.1 for CIPRO. The method was linear in the concentration range of 25–5000 ng/mL. The lower limit of quantification was 25 ng/mL. The intra- and inter-day precision(relative standard deviation) and accuracy(relative error) values were within 12.4%. Each plasma sample was analyzed within 3 min.展开更多
A sensitive, accurate and robust Liquid Chromatography Tandem Mass Spectrometry method has been developed and validated to measure voriconazole trough levels in human plasma. The plasma samples were mixed with flucona...A sensitive, accurate and robust Liquid Chromatography Tandem Mass Spectrometry method has been developed and validated to measure voriconazole trough levels in human plasma. The plasma samples were mixed with fluconazole as an Internal Standard and directed to protein precipitation and drug extraction. An aliquot of 1 μl was injected into the chromatographic system and separated by the Acquity BEH C18 column at a flow rate of 0.30 ml/min in a gradient mobile phase consisting of acetonitrile, Ultrapure water (UPW), methanol and formic acid. Voriconazole was detected by a Triple Quadrupole Detector (TQD) operating on Multiple Reaction Monitoring (MRM) and a positive ion mode Electrospray ionization (ESI) Q1 mass: 350.1 m/z, Q3 mass: 281.1 m/z. Method linearity of the calibration curve (0.10 - 8.00 μg/ml) indicated a correlation coefficient r ≥ 0.99. The intra and inter-assay accuracy was within 85% - 115% and the intra and inter-assay precision was ≤5.76%. Voriconazole recovery percentage was between 97.69 - 119.62%. The method was successively applied in routine voriconazole TDM.展开更多
A simple, rapid, sensitive and reproducible method for enantiomer analysis of methamphetamine, amphetamine, cathinone and methcathinone was developed and validated. The compounds were extracted from equine plasma and ...A simple, rapid, sensitive and reproducible method for enantiomer analysis of methamphetamine, amphetamine, cathinone and methcathinone was developed and validated. The compounds were extracted from equine plasma and urine using a fast liquid-liquid extraction procedure. Only one milliliter plasma and one hundred microliter urine sample is needed for analysis. The extraction procedure had good recovery (>70%) and the matrix effect was negligible. Enantiomer differentiation and confirmation were achieved using liquid chromatography with chiral stationary phase and mass spectrometry detection. The method demonstrated excellent reproducibility with intra-day and inter-day precision of lower than 5%. The lower limits of detection for all of the compounds studied here were at low pg/mL level for both plasma and urine. This is the first report of the analysis of four chiral compounds in equine plasma and urine. Routine application was demonstrated for (S)- and (R)-enantiomer differentiation.展开更多
Cellulose is a kind of saccharide that is the main component in cell walls of plants and therefore is the organic compound that exists in the largest amount in nature. The purpose of this experiment is to convert cell...Cellulose is a kind of saccharide that is the main component in cell walls of plants and therefore is the organic compound that exists in the largest amount in nature. The purpose of this experiment is to convert cellulose to a fuel. Radio frequency (RF) in-liquid plasma is generated in a cellulose distributed solution and a glucose solution, and the generation gas rate is measured. While hydrogen is the main gas generated by the plasma breakdown, carbon monoxide, carbon dioxide, and low-grade flammable gases are also produced. In the glucose water solution or the glucose distributed solution, the solution itself evaporates and decomposes inside the plasma but since the saccharides are non-volatile, they cannot penetrate into the plasma and are not decomposition. However, when the cellulose is at concentrations of 30 wt% or more, it becomes granular and can directly enter the plasma as a solid, where the plasma decomposes the cellulose itself, significantly increasing the amount of gas generated. In addition, the spectrometry of the plasma emission shows the solution after the creation of plasma has the ability to absorb ultraviolet light.展开更多
Summary： A liquid chromatography-tandem mass spectrometry （LC-MS/MS） method was developed and validated for the determination of butoconazole in human plasma. Human plasma samples of 0.2 μL were pretreated by a si...Summary： A liquid chromatography-tandem mass spectrometry （LC-MS/MS） method was developed and validated for the determination of butoconazole in human plasma. Human plasma samples of 0.2 μL were pretreated by a single step protein precipitation procedure and analyzed using a high performance liquid chromatography （HPLC） electrospray tandem mass spectrometer system. The compounds were eluted isocratically on an Inertsil ODS-SP column （100 min×2.1 mm, 3 μm）, ionized using a positive ion atmospheric pressure electrospray ionization source and analyzed using multiple reaction monitoring （MRM） mode. The ion transitions monitored were m/z 412.8→q65.1 for butoconazole and m/z 453.4→230.3 for the internal standard. The chromatographic run time was 3.5 min per injection, with retention time of 2.47 rain and 2.15 min for butoconazole and repaglinide, respectively. The method was validated to be linear over the range of 20 to 8000 pg/mL （r〉0.999） by using a weighted （1/x2） quadratic regression. The mean recovery rate was more than 86.7%, and the intra- and inter-day precision of the quality control samples （QCs） was less than 8.3% and the accuracy ranged from 96.0% to 110.2%, which indicated that the quantitative method was reliable and accurate. The method is simple, rapid, and has been applied successfully to a pharmacokinetics study of butoconazole nitrate suppositories in healthy Chinese females.展开更多
Non-steroidal anti-inflammatory drugs (NSAIDs) are classified as Class 4 agents by the Association of Racing Commissioners International and are banned in racehorses during competition in Pennsylvania (PA). To control...Non-steroidal anti-inflammatory drugs (NSAIDs) are classified as Class 4 agents by the Association of Racing Commissioners International and are banned in racehorses during competition in Pennsylvania (PA). To control the abuse of these agents in racehorses competing in PA, a forensic method for screening and confirmation of the presence of these agents is needed. Equine plasma (0.5 mL) was acidified with 75 μL 1M H3PO4 to increase recovery of the analytes by liquid-liquid extraction using methyl tert-butyl ether (MTBE). Extracted analytes were separated by reversed-phase liquid chromatography using a C8 column under gradient condition. All 16 analytes were detected, quantified and confirmed using a triple quadrupole tandem mass spectrometry with selected reaction monitoring (SRM) in both negative and positive electrospray ionization modes. The limit of detection, quantification and confirmation of the analytes were 1.0 - 5.0 ng/mL, 1.0 - 5.0 ng/mL and 1.0 - 20 ng/mL, respectively. The linear dynamic range of quantification was 5.0 - 200 ng/mL. The method is routinely used in anti-doping analysis to control the abuse of NSAIDs in racehorses competing in PA.展开更多
A laser-produced plasma(LPP) source was built using liquid as target and a Nd:YAG laser as the irradiation laser, and the LPP source's radiation with ethanol and acetone target respectively was measured by an AXUV...A laser-produced plasma(LPP) source was built using liquid as target and a Nd:YAG laser as the irradiation laser, and the LPP source's radiation with ethanol and acetone target respectively was measured by an AXUV100 silicon photodiode combined with a McPHERSON model 247 grazing incidence monochromator of the resolution Δλ≤0.075 nm and the wavelength scanning interval 0.5 nm. Both ethanol and acetone target LPP source had EUV emission at 11～20 nm wavelength. The comparison between the spectra of the two kinds of target materials shows that all the two kinds of target source's spectra are the result of oxygen ions' transitions under current source's parameters, but the spectrum intensity from different target sources is different. The spectra intensity from the ethanol target is higher than that from the acetone target. In addition, the target liquid is forced into the vacuum chamber by the background pressure supported by the connected external high pressure gas, and the influence of the background pressure on the source's intensity is investigated.展开更多
An atmospheric-pressure dielectric barrier discharge （DBD） gas-liquid cold plasma was employed to synthesize Cu-doped TiO~ nanoparticles in an aqueous solution with the assistance of [C2MIM]BF4 ionic liquid （IL） a...An atmospheric-pressure dielectric barrier discharge （DBD） gas-liquid cold plasma was employed to synthesize Cu-doped TiO~ nanoparticles in an aqueous solution with the assistance of [C2MIM]BF4 ionic liquid （IL） and using air as the working gas. The influences of the discharge voltage, IL and the amount of copper nitrite were investigated. X-ray diffraction, N2 adsorption-desorption measurements and UV-Vis spectroscopy were adopted to characterize the samples. The results showed that the specific surface area of TiO2 was promoted with Cu-doping （from 57.6 m^2.g^-1 to 106.2 m^2.g^-1 with 3% Cu-doping）, and the content of anatase was increased. Besides, the band gap energy of TiO~ with Cu-doping decreased according to the UV-Vis spec- troscopy test. The 3%Cu-IL-TiO2 samples showed the highest eificiency in degrading methylene blue （MB） dye solutions under simulated sunlight with an apparent rate constant of 0.0223 min-1, which was 1.2 times higher than that of non-doped samples. According to the characterization results, the reasons for the high photocatalytic activity were discussed.展开更多
文摘A rapid and sensitive liquid chromatography-tandem mass spectrometric（LC-MS/MS） assay method has been developed and fully validated for the simultaneous quantification of pravastatin and aspirin in human plasma.Furosemide was used as an internal standard.Analytes and the internal standard were extracted from human plasma by liquid-liquid extraction technique using methyl tertiary butyl ether.The reconstituted samples were chromatographed on a Zorbax SB-C;8 column by using a mixture of 5 mM ammonium acetate buffer and acetonitrile（20:80,v/v） as the mobile phase at a flow rate of 0.8 mL/min.The calibration curve obtained was linear（r≥0.99） over the concentration range of 0.50-600.29 ng/mL for pravastatin and 20.07-2012.00 ng/mL for aspirin.Method validation was performed as per FDA guidelines and the results met the acceptance criteria.A run time of 2.0 min for each sample made it possible to analyze more than 400 human plasma samples per day.The proposed method was found to be applicable to clinical studies.
基金the Natural Science Foundation of Shannxi ,China (2005E103)
文摘The lanthanum trivalent ion doped TiO2 nanopowders were prepared by liquid plasma spray with solution of titanium tetra-tert-butoxide and alcohol as feedstock and La(NO3)3·6H2O as doping component. The photocatalytic activity of samples at different doping concentrations in photocatalytic degradation of methyl orange was discussed. The powders were characterized by Transmission Electron Microscopy (TEM) and X-Ray Diffraction (XRD), and the effect of doped ion on the pattern, phase composition and crystallite sizes were analyzed. The results indicated that lanthanum trivalent ion doped TiO2 nanopowders could be prepared by liquid plasma spray. Lanthanum trivalent ion doping increased the photocatalytic activity of TiO2 greatly, the optimal doping concentration was 0.5%. The doped powders were the mixture of anatase phase and rutile phase. The contents of anatase phase decreased firstly and then increased with an increase in the contents of lanthanum trivalent ion. Doping lanthanum trivalent ion could make the TiO2 nanopowders uniform and reduced its particle size.
文摘A novel bioanalytical method was developed and validated for the quantitative determination of darunavir（DRV） in rat plasma by employing hydrophilic interaction chromatography and tandem mass spectrometry（HILIC-MS/MS） with supported liquid extraction（SLE）.lrbesartan（IRB） was used as an internal standard（IS）.The analyte in rat plasma（200 μL） was isolated through SLE using ethyl acetate as the eluting solvent.The chromatographic separation was achieved on Luna-HILIC（250 mm × 4.6 mm,5 μm）column with a mobile phase of 0.1% of formic acid in water：acetonitrile（5：95,v/v）,at a constant flow rate of 1.0mL/min.The MS/MS ion transitions for DRV（548.1→392.0） and IS（429.2→207.1） were monitored on an ion trap mass spectrometer,operating in the multiple reaction monitoring（MRM） mode.The lower limit of quantitation（LLOQ） was 0.2 ng/mL and quantitation range was 0.2-5000 ng/mL.The method was validated for its selectivity,sensitivity,carryover,linearity,precision,accuracy,recovery,matrix effect and stability.The method was successfully applied to pharmacokinetic study in rats.
基金supported by the National Science Foundation of China(No.20973028)
文摘Pd-containing ionic liquid （IL） 1-hexyl-3-methylimidazolium tetrafluoroborate （C6MIMBF4） immobilized on γ-Al2O3 （Pd-IL/γ-Al2O3） was prepared and characterized by Fourier transform infrared spectroscopy （FTIR）, scanning electron microscopy （SEM） and Brunauer-Emmett- Teller （BET） analysis. The influences of C6MIMBF4 loading and Pd on methane conversion to C2 hydrocarbons under cold plasma were investigated. FTIR and SEM analyses indicated that C6MIMBF4 had been successfully immobilized on γ-Al2O3 and the C6MIMBF4 showed excellent stability under cold plasma. The results of BET and methane conversion showed that with the increase in immobilization amount of C6MIMBF4 onto γ-Al2O3, the specific surface area and pore volume of IL/γ-Al2O3 decreased, while the selectivity and yield of C2 hydrocarbons increased. The selectivity of C2 hydrocarbons was 94.6% when the loading of C6MIMBF4 was 40%, and the percentage of C2H4 in C2 hydrocarbons was as high as 64% when using Pd-IL/γ-Al2O3 as a catalyst with no conventional thermal reduction treatment. Optical emission spectra （OES） from the cold plasma reactor during methane conversion were also studied. The results indicated that the intensity of the C2, CH, H, and C active species from methane and hydrogen decomposition increased when IL/γ-Al2O3 or Pd-IL/γ-Al2O3 was introduced into the plasma system. Based on the analyses of the gas product and OES spectra, it can be concluded that the surface catalyzed reactions between plasma and ionic liquid were very important for the reduction of Pd2＋ and the formation of C2H4.
基金supported by National Natural Science Foundation of China(No.10905049)the Fundamental Research Funds for the Central Universities(Nos.2010ZY52,2011YXL059)
文摘The angular distribution and pressure force of droplets ejected from liquid water and glycerol ablated by nanosecond laser pulses are investigated under different viscosities in laser plasma propulsion. It is shown that with increasing viscosity, the distribution angles present a decrease tendency for two liquids, and the angular distribution of glycerol is smaller than that of water. A smaller distribution leads to a higher pressure force generation. The results indicate that ablation can be controlled by varying the viscosity of liquid propellant in laser plasma propulsion.
基金Project supported by the Science and Technology Programme of Beijing Municipal Science and Technology Commission, China (Granted No Y0604002040731)
文摘A cold dielectric barrier discharge （DBD） plasma plume with one highly conductive liquid electrode has been developed to treat thermally sensitive materials, and its preliminary discharging characteristics have been studied. The averaged electron temperature and density is estimated to be 0.6eV and 1011/cm3, respectively. The length of plasma plume can reach 5cm with helium gas （He）, and the conductivity of the outer electrode affects the plume length obviously. This plasma plume could be touched by bare hand without causing any burning or painful sensation, which may provide potential application for safe aseptic skin care. Moreover, the oxidative particles （e.g., OH, O＊, 03） in the downstream oxygen （02） gas of the plume have been applied to treat the landfill leachate. The results show that the activated 02 gas can degrade the landfill leachate effectively, and the chemical oxygen demand （COD）, conductivity, biochemical oxygen demand （BOD）, and suspended solid （SS） can be decreased by 52%, 57%, 76% and 92%, respectively.
基金financially supported by National Natural Science Foundation of China (Nos. 51777206 and 51541807)Natural Science Foundation of Anhui Province (Nos. 1708085MB47 and 1708085MA13)+2 种基金Foundation of Anhui Province Key Laboratory of Medical Physics and Technology (No. LMPT2017Y7BP0U1581)Doctoral Fund of Ministry of Education of China (No. 2017M612058)Specialized Research Fund for the Doctoral Program of Hefei University of Technology (Nos. JZ2016HGBZ0768, JZ2016HGBZ0769, and JZ2017HGBZ0944)
文摘A typical quinolones antibiotic ciprofloxacin(CIP) in aqueous solution was degraded by a gas–liquid discharge non-thermal plasma system. The discharge plasma power and the emission intensity of the excited reactive species(RS) generated in the gas phase were detected by the oscilloscope and the optical emission spectroscopy. The effects of various parameters on CIP degradation, i.e. input powers, initial concentrations addition of radical scavengers and p H values were investigated. With the increase of discharge power, the degradation efficiency increased but the energy efficiency significantly reduced. The degradation efficiency also reduced under high concentration of initial CIP conditions due to the competitive reactions between the plasma-induced RS with the degradation intermediates of CIP. Different radical scavengers(isopropanol and CCl_4) on ·OH and H· were added into the reaction system and the oxidation effects of ·OH radicals have been proved with high degradation capacity on CIP.Moreover, the long-term degradation effect on CIP in the plasma-treated aqueous solution proved that the long-lived RS(H_2O_2 and O_3, etc) might play key roles on the stay effect through multiple aqueous reactions leading to production of ·OH. The degradation intermediates were determined by the method of electrospray ionization(+)-mass spectroscopy, and the possible degradation mechanism were presented.
基金supported by a grant of the Guangzhou Boji Clinical Research Center of New Drugs,Guangzhou,Guangdong,China
文摘A simple and sensitive liquid chromatographic method was developed for quantification of cefotetan disodium (CTT),a semi-synthetic cephamycin antibiotic,in human plasma.CTT and the internal standard chloramphenicol were extracted from plasma by a simple one-step protein precipitation with 35% (v/v) perchloric acid.Separation was carried out on a reverse-phase C18 column with a mobile phase of acetonitile-water containing 0.5% (v/v) phosphoric acids (20:80,v/v) at a flow rate of 1.0 mL/min.The column effluent was monitored by UV detection at 300 nm.The column temperature was maintained at 40°C.This method demonstrated good linearity in the range of 0.525-300.0 μg/mL,with correlation coefficients greater than 0.99.The limit of quantification (LOQ) was 0.525 μg/mL in human plasma.Intra-and inter-day precisions were less than 6.63% in terms of relative standard deviation (RSD).The accuracy,when expressed by the bias,ranged from 0.57% to 4.04%.The mean extraction recovery of CTT was higher than 40.94%.The method was found to be precise,accurate,and specific for CTT quantitative analysis,and was successfully applied for a pharmacokinetic study of CTT after a single intravenous dose of 1.0 g of CTT in healthy Chinese subjects.
基金supported by National Natural Science Foundation of China (No.10675078)
文摘Chitosan （CTS） coatings contained calcium （Ca） and phosphorus （P） on titanium （Ti） surface are prepared by the cathode liquid phase plasma technology （CLPT）, in a certain concentration electrolyte solution with selective additions of ammonium dihydrogen phosphate and calcium nitrate. It is indicated that the parameters for a stable discharge are voltage of 400 V, frequency of 100 Hz, duty cycle of 30% based on a large amount of experiment data. The morphology, structure and composition of the coated samples are studied by SEM, FTIR, XRD, XPS. The results demonstrate that the composite coatings are uniform, and some solid particles of inorganic salt containing calcium and phosphorus dispersed on the coatings. CA tests show that the samples treated by the liquid plasma became less hydrophilic. The variation of hydrophilicity on the CLPT treated titanium is attributed to the change of the function groups on the sample surface. Meanwhile, a possible formation mechanism of the composite coatings is discussed.
基金partially supported by JSPS KAKENHI Grant Number 15K05833
文摘The objectives of this research were to understand the process of converting toluene into phenol in a one-step process directly from a water–toluene mixture using the plasma in-liquid method.Experiments were conducted using 27.12 MHz radio frequency（RF） in-liquid plasma to decompose a solution of 30% toluene. Based on the experimental results as evaluated using gas chromatography–mass spectrometry（GC–MS）, along with additional analysis by the Gaussian calculation, density functional theory（DFT） hybrid exchange–correlational functional（B3LYP）and 6-311 G basis, the phenol generated from toluene was quantified including any by-products.In the experiment, it was found that OH radicals from water molecules produced using RF inliquid plasma play a significant role in the chemical reaction with toluene. The experimental results suggest that phenol can be directly produced from a water–toluene mixture. The maximum phenol yields were 0.0013% and 0.0038% for irradiation times of 30s and 60s,respectively, at 120 W.
文摘Three extraction methods were compared for their efficiency to analyze sitagliptin and simvastatin in rat plasma by LC-MS/MS, including （1） liquid-liquid extraction （LLE）, （2） solid phase extraction （SPE） and （3） supported liquid extraction （SLE）. Comparison of recoveries of analytes with different extraction methods revealed that SLE was the best extraction method. The detection was facilitated with ion trap-mass spectrometer by multiple reactions monitoring （MRM） in a positive ion mode with ESI. The transitions monitored were m./z 441.1→325.2 for simvastatin, 408.2→235.1 for sitagliptin and 278.1→260.1 for the IS. The lower limit of quantification （LLOQ） was 0.2 ng/mL for sitagliptin and 0.1 ng/mL for simvastatin. The effective SLE offers enhanced chromatographic selectivity, thus facilitating the potential utility of the method for routine analysis of biological samples along with pharmacokinetic studies.
基金supported by National Natural Science Foundation of China(No.52107162)the Science and Technology Projects of Shaanxi Province(No.2022CGBX12)the Science and Technology Projects of Xi’an City(No.2021SFCX0005)。
文摘This paper aims to explore the effects of a rotating plasma-activated liquid on the dynamic propagation and biomedical application of a helium plasma jet.The spatial distribution of reactive species and the associated physico-chemical reactions are altered by the rotating liquid,which shows a significant weakening in the axial propagation of the plasma bullet and a strengthening in its radial expansion at the liquid surface.The phenomenon is prompted by the nonzero rotational velocity of the liquid and is regulated by airflow,target distance and liquid permittivity.The concentrations of aqueous reactive species,especially OH and O~-,and the inactivation effectiveness on cancer cells are weakened,indicating that a rotating liquid is not conducive to water treatment of the plasma jet although the treatment area of the plasma jet increases dynamically.This finding is of significance for the plasma–liquid interaction and the biomedical-related applications of plasma jets.
文摘A rapid and sensitive liquid chromatography tandem mass spectrometry(LC-MS/MS) method has been developed and validated for the determination of moxifloxacin(MOXI) in human plasma. After a simple protein precipitation using acetonitrile, the post treatment samples were analysed on a C18 column interfaced with a Triple Quadropole Tandem Mass Spectrometer. Positive electrospray ionization was employed as the ionization source. The mobile phase consisted of 0.1% formic acid–acetonitrile(60:40, v/v). Ciprofloxacin(CIPRO) was used as an internal standard. The analyte and internal standard(CIPRO) were monitored in the multiple reaction monitoring mode(MRM). The mass transition ion-pair has been followed as m/z 402→358.2 for MOXI and 332→288.1 for CIPRO. The method was linear in the concentration range of 25–5000 ng/mL. The lower limit of quantification was 25 ng/mL. The intra- and inter-day precision(relative standard deviation) and accuracy(relative error) values were within 12.4%. Each plasma sample was analyzed within 3 min.
文摘A sensitive, accurate and robust Liquid Chromatography Tandem Mass Spectrometry method has been developed and validated to measure voriconazole trough levels in human plasma. The plasma samples were mixed with fluconazole as an Internal Standard and directed to protein precipitation and drug extraction. An aliquot of 1 μl was injected into the chromatographic system and separated by the Acquity BEH C18 column at a flow rate of 0.30 ml/min in a gradient mobile phase consisting of acetonitrile, Ultrapure water (UPW), methanol and formic acid. Voriconazole was detected by a Triple Quadrupole Detector (TQD) operating on Multiple Reaction Monitoring (MRM) and a positive ion mode Electrospray ionization (ESI) Q1 mass: 350.1 m/z, Q3 mass: 281.1 m/z. Method linearity of the calibration curve (0.10 - 8.00 μg/ml) indicated a correlation coefficient r ≥ 0.99. The intra and inter-assay accuracy was within 85% - 115% and the intra and inter-assay precision was ≤5.76%. Voriconazole recovery percentage was between 97.69 - 119.62%. The method was successively applied in routine voriconazole TDM.
文摘A simple, rapid, sensitive and reproducible method for enantiomer analysis of methamphetamine, amphetamine, cathinone and methcathinone was developed and validated. The compounds were extracted from equine plasma and urine using a fast liquid-liquid extraction procedure. Only one milliliter plasma and one hundred microliter urine sample is needed for analysis. The extraction procedure had good recovery (>70%) and the matrix effect was negligible. Enantiomer differentiation and confirmation were achieved using liquid chromatography with chiral stationary phase and mass spectrometry detection. The method demonstrated excellent reproducibility with intra-day and inter-day precision of lower than 5%. The lower limits of detection for all of the compounds studied here were at low pg/mL level for both plasma and urine. This is the first report of the analysis of four chiral compounds in equine plasma and urine. Routine application was demonstrated for (S)- and (R)-enantiomer differentiation.
文摘Cellulose is a kind of saccharide that is the main component in cell walls of plants and therefore is the organic compound that exists in the largest amount in nature. The purpose of this experiment is to convert cellulose to a fuel. Radio frequency (RF) in-liquid plasma is generated in a cellulose distributed solution and a glucose solution, and the generation gas rate is measured. While hydrogen is the main gas generated by the plasma breakdown, carbon monoxide, carbon dioxide, and low-grade flammable gases are also produced. In the glucose water solution or the glucose distributed solution, the solution itself evaporates and decomposes inside the plasma but since the saccharides are non-volatile, they cannot penetrate into the plasma and are not decomposition. However, when the cellulose is at concentrations of 30 wt% or more, it becomes granular and can directly enter the plasma as a solid, where the plasma decomposes the cellulose itself, significantly increasing the amount of gas generated. In addition, the spectrometry of the plasma emission shows the solution after the creation of plasma has the ability to absorb ultraviolet light.
基金supported by National Science&Technology Specific Projects in the 12th Five-Year Plan of China(No.2011ZX09302-002-01)
文摘Summary： A liquid chromatography-tandem mass spectrometry （LC-MS/MS） method was developed and validated for the determination of butoconazole in human plasma. Human plasma samples of 0.2 μL were pretreated by a single step protein precipitation procedure and analyzed using a high performance liquid chromatography （HPLC） electrospray tandem mass spectrometer system. The compounds were eluted isocratically on an Inertsil ODS-SP column （100 min×2.1 mm, 3 μm）, ionized using a positive ion atmospheric pressure electrospray ionization source and analyzed using multiple reaction monitoring （MRM） mode. The ion transitions monitored were m/z 412.8→q65.1 for butoconazole and m/z 453.4→230.3 for the internal standard. The chromatographic run time was 3.5 min per injection, with retention time of 2.47 rain and 2.15 min for butoconazole and repaglinide, respectively. The method was validated to be linear over the range of 20 to 8000 pg/mL （r〉0.999） by using a weighted （1/x2） quadratic regression. The mean recovery rate was more than 86.7%, and the intra- and inter-day precision of the quality control samples （QCs） was less than 8.3% and the accuracy ranged from 96.0% to 110.2%, which indicated that the quantitative method was reliable and accurate. The method is simple, rapid, and has been applied successfully to a pharmacokinetics study of butoconazole nitrate suppositories in healthy Chinese females.
文摘Non-steroidal anti-inflammatory drugs (NSAIDs) are classified as Class 4 agents by the Association of Racing Commissioners International and are banned in racehorses during competition in Pennsylvania (PA). To control the abuse of these agents in racehorses competing in PA, a forensic method for screening and confirmation of the presence of these agents is needed. Equine plasma (0.5 mL) was acidified with 75 μL 1M H3PO4 to increase recovery of the analytes by liquid-liquid extraction using methyl tert-butyl ether (MTBE). Extracted analytes were separated by reversed-phase liquid chromatography using a C8 column under gradient condition. All 16 analytes were detected, quantified and confirmed using a triple quadrupole tandem mass spectrometry with selected reaction monitoring (SRM) in both negative and positive electrospray ionization modes. The limit of detection, quantification and confirmation of the analytes were 1.0 - 5.0 ng/mL, 1.0 - 5.0 ng/mL and 1.0 - 20 ng/mL, respectively. The linear dynamic range of quantification was 5.0 - 200 ng/mL. The method is routinely used in anti-doping analysis to control the abuse of NSAIDs in racehorses competing in PA.
文摘A laser-produced plasma(LPP) source was built using liquid as target and a Nd:YAG laser as the irradiation laser, and the LPP source's radiation with ethanol and acetone target respectively was measured by an AXUV100 silicon photodiode combined with a McPHERSON model 247 grazing incidence monochromator of the resolution Δλ≤0.075 nm and the wavelength scanning interval 0.5 nm. Both ethanol and acetone target LPP source had EUV emission at 11～20 nm wavelength. The comparison between the spectra of the two kinds of target materials shows that all the two kinds of target source's spectra are the result of oxygen ions' transitions under current source's parameters, but the spectrum intensity from different target sources is different. The spectra intensity from the ethanol target is higher than that from the acetone target. In addition, the target liquid is forced into the vacuum chamber by the background pressure supported by the connected external high pressure gas, and the influence of the background pressure on the source's intensity is investigated.
基金supported by National Natural Science Foundation of China(Nos.21173028,11505019)the Science and Technology Research Project of Liaoning Provincial Education Department(No.L2013464)+2 种基金the Scientific Research Foundation for the Doctor of Liaoning Province(No.20131004)the Program for Liaoning Excellent Talents in University(No.LR2012042)Dalian Jinzhou New District Science and Technology Plan Project(No.KJCX-ZTPY-2014-0001)
文摘An atmospheric-pressure dielectric barrier discharge （DBD） gas-liquid cold plasma was employed to synthesize Cu-doped TiO~ nanoparticles in an aqueous solution with the assistance of [C2MIM]BF4 ionic liquid （IL） and using air as the working gas. The influences of the discharge voltage, IL and the amount of copper nitrite were investigated. X-ray diffraction, N2 adsorption-desorption measurements and UV-Vis spectroscopy were adopted to characterize the samples. The results showed that the specific surface area of TiO2 was promoted with Cu-doping （from 57.6 m^2.g^-1 to 106.2 m^2.g^-1 with 3% Cu-doping）, and the content of anatase was increased. Besides, the band gap energy of TiO~ with Cu-doping decreased according to the UV-Vis spec- troscopy test. The 3%Cu-IL-TiO2 samples showed the highest eificiency in degrading methylene blue （MB） dye solutions under simulated sunlight with an apparent rate constant of 0.0223 min-1, which was 1.2 times higher than that of non-doped samples. According to the characterization results, the reasons for the high photocatalytic activity were discussed.
