A reliable and inexpensive pretreatment procedure in the determination ofβ2-agonists in pork was developped.The procedure used a nanocomposite of multiwalled carbon nanotubes(CNTs)functionalized with graphene(rGO)as ...A reliable and inexpensive pretreatment procedure in the determination ofβ2-agonists in pork was developped.The procedure used a nanocomposite of multiwalled carbon nanotubes(CNTs)functionalized with graphene(rGO)as the reversed dispersive sorbent.It was analyzed after purification by highperformance liquid chromatography,the extraction time and the properties of the nanocomposite were optimized.Under optimized conditions,present method has linear response over concentration range of 0.5–50 ng/mL in pork samples with a satisfactory detection limit close to 0.1 ng/mL.The precisions of the current method(coefficient of variation)are lower than 5%,while recoveries are more than 98.3%.The nanocomposite exhibited high adsorptivity,long-term storage stability,satisfactory anti-interfering activity and high selectivity toward2-agonists compared with those of rGO and CNTs.展开更多
An HPLC method was established to control the quality of PolygonumavculareL. The active ingredients in PolygonumavculareL. samples were extracted with methanol, and then analyzed by high-performance liquid chromatogra...An HPLC method was established to control the quality of PolygonumavculareL. The active ingredients in PolygonumavculareL. samples were extracted with methanol, and then analyzed by high-performance liquid chromatography （HPLC）. The fingerprint of PolygonumavculareL. as well as its 11 typical peaks were established. The HPLC method demonstrated good precision, reproducibility, and stability, with the relative standard deviations of retention time and peak area less than 3%.展开更多
In this experiment,a liquid chromatography tandem mass spectrometry method was built to determine 15 pesticide residues in Chinese cabbage and cucumber samples based on online turbulent flow chromatography purificatio...In this experiment,a liquid chromatography tandem mass spectrometry method was built to determine 15 pesticide residues in Chinese cabbage and cucumber samples based on online turbulent flow chromatography purification.After modified quick,easy,cheap,effective,rugged,and safe(QuEChERS)extraction,extracts were directly injected to the TLX(TurboFlow Liquid Xcalibur)system and brought to TurboFlow™columns for on-line purification and then transferred to analytical column for further separation and analysis.TurboFlow™columns types,transfer flow rate,and transfer time were optimized.Limits of detection and limits of quantification of the method obtained for 15 pesticide residues were ranged between 0.2–1.0μg/kg and 0.5–2.0μg/kg in Chinese cabbage and cucumber samples.Recoveries of pesticide residues were in range of 75.3%–103.7%.Matrix effects for 15 pesticides were in range of 5.6%–106.6%.The developed method has been successfully used for the determination of 15 pesticide residues in real samples.展开更多
The novel pulsed liquid chromatography radionuclide separation method presented here provides a new and promising strategy for the extraction of uranium from seawater.In this study,a new chromatographic separation met...The novel pulsed liquid chromatography radionuclide separation method presented here provides a new and promising strategy for the extraction of uranium from seawater.In this study,a new chromatographic separation method was proposed,and a pulsed nuclide automated separation device was developed,alongside a new chromatographic column.The length of this chromatographic column was 10 m,with an internal warp of 3 mm and a packing size of 1 mm,while the total separation units of the column reached 12,250.The most favorable conditions for the separation of nuclides were then obtained through optimizing the separation conditions of the device:Sample pH in the column=2,sample injection flow rate=5.698 mL/min,chromatographic column heating temperature=60℃.Separation experiments were also carried out for uranium,europium,and sodium ions in mixed solutions;uranium and sodium ions in water samples from the Ganjiang River;and uranium,sodium,and magnesium ions from seawater samples.The separation factors between the different nuclei were then calculated based on the experimental data,and a formula for the separation level was derived.The experimental results showed that the separation factor in the mixed solution of uranium and europium(1:1)was 1.088,while achieving the initial separation of uranium and europium theoretically required a 47-stage separation.Considering the separation factor of 1.50for the uranium and sodium ions in water samples from the Ganjiang River,achieving the initial separation of uranium and sodium ions would have theoretically required at least a 21-stage separation.Furthermore,for the seawater sample separation experiments,the separation factor of uranium and sodium ions was 1.2885;therefore,more than 28 stages of sample separation would be required to achieve uranium extraction from seawater.The novel pulsed liquid chromatography method proposed in this study was innovative in terms of uranium separation and enrichment,while expanding the possibilities of extracting uranium from seawater through chromatography.展开更多
The aim of this work was to develop an automated on-line solid phase extraction(SPE)with liquid chromatography-tandem mass spectrometry method for the detection of fifteen sulfonamides in pork and fish samples.Samples...The aim of this work was to develop an automated on-line solid phase extraction(SPE)with liquid chromatography-tandem mass spectrometry method for the detection of fifteen sulfonamides in pork and fish samples.Samples were extracted with 0.2%formic acid acetonitrile solution,purified by on-line SPE device with HLB column,then separated by XBridge C18 column,using 0.1%formic acid solution and acetonitrile as the mobile phase.Mass spectrometric data was acquired under multiple reaction monitoring(MRM)mode using positive ionization electrospray.Internal standard method was used in the quantification,good linear relationship was got in range of 0.1–100 ng/mL and correlation coefficient was higher than 0.9990.The limits of detection were in the range of 0.125–2.00g/kg and the limits of quantitation were in the range of 0.250–5.00g/kg.Recoveries of the method were in range of 78.3%–99.3%,relative standard deviation were lower than 10%.The method was simple,sensitivity,and could be used for routine supervision and analysis of fifteen sulfonamides in pork and fish.展开更多
An isocratic reversed-phase liquid chromatographic (LC) method is described for the determination of epalrestat and its three stereoisomers (degradation impurities) in drug substance. The LC separation system consiste...An isocratic reversed-phase liquid chromatographic (LC) method is described for the determination of epalrestat and its three stereoisomers (degradation impurities) in drug substance. The LC separation system consisted of a Hypersil C18 column (250 mm×4.6 mm, 5 μm) with a mobile phase comprising methanol, acetonitrile and water (volume ratio 60∶1∶50, pH 4.5) delivered at a flow rate of 1.6 mL/min and UV detection at 280 nm. The proposed LC method is simple and selective for the determination of the stereoisomers of epalrestat in the drug substance with a limit of detection and quantification of 3.9 μg/mL and 4.9 μg/mL, respectively. The stereoisomers were identified by liquid chromatography-mass spectrometry (LC-MS).展开更多
Taraxacum kok-saghyz(TKS)is rich in natural rubber(NR),a natural organic macromolecular compound composed of cis-1,4-polyisoprene,and may become the second NR-bearing plant for biochemical engineering development.In t...Taraxacum kok-saghyz(TKS)is rich in natural rubber(NR),a natural organic macromolecular compound composed of cis-1,4-polyisoprene,and may become the second NR-bearing plant for biochemical engineering development.In this paper,a rapid and quantitative ultra-high performance liquid chromatography tandem mass spectrometry(UHPLCMS/MS)method was established for determination of macromolecular biosynthesis substrate(dimethylallyl pyrophosphate,DMAPP)and initiator(farnesyl pyrophosphate,FPP)contained in TKS.A Kromasil C18 chromatographic column was used for separation,and the multi-reaction monitoring mode(MRM)of triple quadrupole mass spectrometry was used for detection.Quantification was performed by external calibration method.The results showed that the limit of detection(LOD)and the limit of quantitation(LOQ)of DMAPP were 2.42μg/L and 7.26μg/L,respectively,and the LOQ and the LOD of FPP were 1.02μg/L and 3.05μg/L,respectively.At a concentration of 1—1000μg/L,both analytes had good determination coefficients(>0.999)of calibration curve.The recoveries of DMAPP and FPP were between 99.0%and 117.1%.In real samples detection,the contents of DMAPP and FPP in TKS samples were between 23.32—82.77μg/L and 12.03—85.67μg/L,respectively.Thus,this approach is a reliable method to quantify DMAPP and FPP in TKS.展开更多
The measurement of urine catecholamine and metanephrine concentrations is important for biochemical screening and diagnosis of pheochromocytoma.The goal of this work was to develop a simple liquid chromatography-tande...The measurement of urine catecholamine and metanephrine concentrations is important for biochemical screening and diagnosis of pheochromocytoma.The goal of this work was to develop a simple liquid chromatography-tandem mass spectrometry(LC-MS/MS)method for determining catecholamines and metanephrines in urine to replace an existing liquid chromatographic method using electrochemical detection.Urine samples were prepared using Oasis weak-cation-exchange cartridges.The eluate was analyzed on an Agilent ZORBAX Eclipse Plus Phenyl-Hexyl column in 3 min.Adrenaline,noradrenaline,dopamine,metanephrine,normetanephrine,and their deuterated internal standards were monitored in positive electrospray ionization mode by multiple reaction monitoring(MRM).No evidence of ion suppression was observed.The assay was linear up to 5μmol/L for adrenaline,5μmol/L for noradrenaline,6.1μmol/L for dopamine,5.6μmol/L for metanephrine,and 34.6μmol/L for normetanephrine,with lower limits of quantification of 5,5,12,6 and 7nmol/L,respectively.The intra-day and inter-day precisions for all analytes ranged from 0.59%to 4.64%and1.98%to 4.80%,respectively.External quality assurance samples were assayed and showed excellent agreement with the target values.This simple method provides an improved assay for determining urine catecholamines and metanephrines.展开更多
A high-performance liquid chromatography was describ-ed to measure the concentration of human 3-methylhistidine in urine witho-phthaldialdehyde pre-column derivatization.This assay system resultedin a clear separation...A high-performance liquid chromatography was describ-ed to measure the concentration of human 3-methylhistidine in urine witho-phthaldialdehyde pre-column derivatization.This assay system resultedin a clear separation of 3-methylhistidine derivative from other derivativ-es in urine within 25 min.Linearity,recovery and coefficients of vari-ation were studied.The method has been successfully applied to routineanalysis for clinical studies and diagnosis.展开更多
Chinese herbal compound is playing an important role on curing human diseases.And it has been a trend that Chinese herbal compound is being used all over the world in 21 century.However,our Chinese herbal compound is ...Chinese herbal compound is playing an important role on curing human diseases.And it has been a trend that Chinese herbal compound is being used all over the world in 21 century.However,our Chinese herbal compound is facing serious challenge for the lack of canonical system of quality criterion for Chinese herbal compound so it has been a urgent problem to set up the quality control standards and reveal therapeutic basis of Chinese herbal compound.In order to give full play to the advantages of Chinese herbal compound,modern scientific and technological is used to research of Chinese herbal compound,especially the high performance liquid chromatography tandem mass spectrometry(HPLC-MS),because it is high sensitive,rapid,and obtain more information.It is very necessary that HPLC-MS is uesed to elucidate the effective components of basic substances of Chinese Herbal Compound,and endow traditional Chinese medicine with modern scientific connotation.展开更多
The method of reversed-phase high performance liquid chromatography was established for the determination of effective components in OC-CS spray using double wavelength UV detection.The method was utilized under follo...The method of reversed-phase high performance liquid chromatography was established for the determination of effective components in OC-CS spray using double wavelength UV detection.The method was utilized under following conditions:a column of Kromasil C18(250 mm × 4.6 mm,5 μm),mobile phase consisting of methanol/water(80 /20) at a flow rate of 0.8 mL/min,column temperature of 25 ℃,and the UV detection at 227 nm and 300 nm.Three key components in OC-CS spray could be distinguished clearly,including o-chlorobenzalmalononitrile(CS),oleoresin capsicum(OC) and dihydrocapsaicin(DC).This method has the advantages of fast,simple and satisfactory linear relationship between UV absorption and concentration.It may be considered to turn into a standard method for detection of related components in the spray.展开更多
Modification was made on the reversed-phase high performance liquid chromatography(RP-HPLC)with Yue et al's method as a base.The modified RP-HPLC was used to detect leukotriene B_4(LTB_4)and 5-hydroxyeicosatetraen...Modification was made on the reversed-phase high performance liquid chromatography(RP-HPLC)with Yue et al's method as a base.The modified RP-HPLC was used to detect leukotriene B_4(LTB_4)and 5-hydroxyeicosatetraenoic acid(5-HETE).It was found that the modified method has the merits of simpler procedures,shorter testing time and more satisfactory efficacy.展开更多
After joining the faculty at Toyohashi University of Technology (TUT) in 1978, the author has found two areas in separation sciences where microcolumn liquid chromatography (micro LC) can be beneficial One is the hyph...After joining the faculty at Toyohashi University of Technology (TUT) in 1978, the author has found two areas in separation sciences where microcolumn liquid chromatography (micro LC) can be beneficial One is the hyphenated techniques between many spectroscopic methods such as mass (MS), infrared (FT IR) and atomic emission (ICP), and micro LC The other one is rather difficult, but basic and theoretical approach which deals with retention mechanism in LC The latter project has especially been giving him a lot of scientific funs and honors in the last 20 years On the occasion of being awarded by The Society for Chromatographic Sciences the author would like to summarize his contributions to this topic which asks us "What Is Chromatographic Retention?展开更多
Liquid chromatography/mass spectrometry (LC/MS) is now considered to be the most promising analytical method for the determination of biological substances, especially nonvolatile or highly polar substances However, s...Liquid chromatography/mass spectrometry (LC/MS) is now considered to be the most promising analytical method for the determination of biological substances, especially nonvolatile or highly polar substances However, some compounds do not show enough sensitivity in LC/MS and soft ionization methods commonly used in LC/MS, such as electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI), sometimes do not give satisfactory structural information This report presents an overview of the derivatization methods in the LC/MS analysis of neurosteroids or neuroactive neurosteroids, which are synthesized and accumulated in the nervous system The derivatization of pregnenolone 3 sulfate, one of these steroids, with 4 ( N,N dimethylaminosulfonyl) 7 hydrazino 2,1,3 benzoxadiazole gave a satisfactory sensitivity during the quantitative analysis using LC/ESI MS The obtained results are much lower than those previously obtained using gas chromatography/mass spectrometry or radioimmunoassay On the other hand, the derivatization to acetate was useful for the treatment of labile catechol estrogens in rat brains and gave enough structural information in LC/APCI MS, which confirmed the existence of catechol estrogens in mammalian展开更多
A rapid method was presented for the determination of 19 polyphenols in tea by ultra-high performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry(UPLC-Q-TOF MS).Tea samples were extr...A rapid method was presented for the determination of 19 polyphenols in tea by ultra-high performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry(UPLC-Q-TOF MS).Tea samples were extracted by 50%(V/V)ethanol,then separated by Waters Acquity BEH C18 column using a binary solvent system composed of acetonitrile and water(0.1%formic acid)by gradient elution.The analytes were determined by Q-TOF MS in TOF MS and information dependent acquisition(IDA)-MS/MS mode.The results showed that mass accuracy error of the 19 polyphenols were lower than 5.0×10^(-6),good linear relationship was got in range of 0.2–500μg/L and correlation coefficient was higher than 0.9990.The LOD was in the range of 0.002–0.100 mg/kg and the LOQ was in the range of 0.004–0.200 mg/kg.Recovery of the method was in range of 78.4%–109.2%with spike levels of 0.004–2.000 mg/kg,relative standard deviations were lower than 10%.The method was simple,rapid and accurate.It could be used for the rapid screening and quantitative analysis of 19 polyphenols in tea.展开更多
Modern porous monoliths have been conceived as a new class of stationary phases for high performance liquid chromatography(HPLC) in classical columns in the early 1990s and later extended to the capillary format.These...Modern porous monoliths have been conceived as a new class of stationary phases for high performance liquid chromatography(HPLC) in classical columns in the early 1990s and later extended to the capillary format.These monolithic materials are prepared using simple processes carried out in an external mold(inorganic monoliths) or within the confines of the column(organic monoliths and all capillary columns).These methods afford macroporous materials with large through-pores that enable applications in a rapid flow-through mode.Since all the mobile phase must flow through the monolith,the convection considerably accelerates mass transport within the monolithic separation medium and improves the separations.As a result,the monolithic columns perform well even at very high flow rates.The applications of monolithic capillary columns are demonstrated on numerous separations in the HPLC mode.展开更多
Five thyreostats(TSs),namely tapazole,thiouracil,methylthiouracil,propylthiouracil,and phenylthiouracil,were determined in bovine urine using ultra-high performance liquid chromatography-tandem mass spectrometry(UHPLC...Five thyreostats(TSs),namely tapazole,thiouracil,methylthiouracil,propylthiouracil,and phenylthiouracil,were determined in bovine urine using ultra-high performance liquid chromatography-tandem mass spectrometry(UHPLC-MS/MS)in positive electrospray ionization mode.Extraction and clean-up were achieved using a ChemElut cartridge with tert-butyl methyl ether,without a derivatization step.Separation was achieved on an Acquity UPLC SS T3 column.The mobile phase was acetonitrile and water containing 0.2%(v/v)formic acid.The mass spectrometer was operated in multiple reaction monitoring mode.Urine samples were spiked with TS solution at levels corresponding to 5,10,15,and 20μg/L.The accuracy(internal standard corrected)ranged from 92%to 107%,with a repeatability precision(relative standard deviation,RSD)less than 15%for all five analytes.The RSDs within-laboratory reproducibility was less than 26%.The decision limits(CCα)and detection capabilities(CCβ)were obtained from a calibration curve and were in the ranges of 3.1-6.1μg/L and 4.0-7.4μg/L,respectively.The CCαand CCβvalues were below the recommended concentration,which was set at 10μg/L.The results show that the described method is suitable for the direct detection of TSs in bovine urine.This method can also be used to determine TSs in porcine urine.展开更多
基金This study was financially supported by the Program of Technology Gansu Province(1309RTSA025,1009FTGA018,1306TTPA036).
文摘A reliable and inexpensive pretreatment procedure in the determination ofβ2-agonists in pork was developped.The procedure used a nanocomposite of multiwalled carbon nanotubes(CNTs)functionalized with graphene(rGO)as the reversed dispersive sorbent.It was analyzed after purification by highperformance liquid chromatography,the extraction time and the properties of the nanocomposite were optimized.Under optimized conditions,present method has linear response over concentration range of 0.5–50 ng/mL in pork samples with a satisfactory detection limit close to 0.1 ng/mL.The precisions of the current method(coefficient of variation)are lower than 5%,while recoveries are more than 98.3%.The nanocomposite exhibited high adsorptivity,long-term storage stability,satisfactory anti-interfering activity and high selectivity toward2-agonists compared with those of rGO and CNTs.
文摘An HPLC method was established to control the quality of PolygonumavculareL. The active ingredients in PolygonumavculareL. samples were extracted with methanol, and then analyzed by high-performance liquid chromatography （HPLC）. The fingerprint of PolygonumavculareL. as well as its 11 typical peaks were established. The HPLC method demonstrated good precision, reproducibility, and stability, with the relative standard deviations of retention time and peak area less than 3%.
基金National Key Research and Development Program of China(Project No.2018YFC1603400)Science and Technology Program of Hebei Province(Project No.19225503D)Technical Support Project of State Administration for Market Regulation(Project No.2019YJ009).
文摘In this experiment,a liquid chromatography tandem mass spectrometry method was built to determine 15 pesticide residues in Chinese cabbage and cucumber samples based on online turbulent flow chromatography purification.After modified quick,easy,cheap,effective,rugged,and safe(QuEChERS)extraction,extracts were directly injected to the TLX(TurboFlow Liquid Xcalibur)system and brought to TurboFlow™columns for on-line purification and then transferred to analytical column for further separation and analysis.TurboFlow™columns types,transfer flow rate,and transfer time were optimized.Limits of detection and limits of quantification of the method obtained for 15 pesticide residues were ranged between 0.2–1.0μg/kg and 0.5–2.0μg/kg in Chinese cabbage and cucumber samples.Recoveries of pesticide residues were in range of 75.3%–103.7%.Matrix effects for 15 pesticides were in range of 5.6%–106.6%.The developed method has been successfully used for the determination of 15 pesticide residues in real samples.
基金the Natural Science Foundation of Jiangxi Province,China(No.20202BABL203004)the Opening Project of the State Key Laboratory of Nuclear Resources and Environment(East China University of Technology)(No.2022NRE23)the Opening Project of Jiangxi Province Key Laboratory of Polymer Micro/Nano Manufacturing and Devices(No.PMND202101).
文摘The novel pulsed liquid chromatography radionuclide separation method presented here provides a new and promising strategy for the extraction of uranium from seawater.In this study,a new chromatographic separation method was proposed,and a pulsed nuclide automated separation device was developed,alongside a new chromatographic column.The length of this chromatographic column was 10 m,with an internal warp of 3 mm and a packing size of 1 mm,while the total separation units of the column reached 12,250.The most favorable conditions for the separation of nuclides were then obtained through optimizing the separation conditions of the device:Sample pH in the column=2,sample injection flow rate=5.698 mL/min,chromatographic column heating temperature=60℃.Separation experiments were also carried out for uranium,europium,and sodium ions in mixed solutions;uranium and sodium ions in water samples from the Ganjiang River;and uranium,sodium,and magnesium ions from seawater samples.The separation factors between the different nuclei were then calculated based on the experimental data,and a formula for the separation level was derived.The experimental results showed that the separation factor in the mixed solution of uranium and europium(1:1)was 1.088,while achieving the initial separation of uranium and europium theoretically required a 47-stage separation.Considering the separation factor of 1.50for the uranium and sodium ions in water samples from the Ganjiang River,achieving the initial separation of uranium and sodium ions would have theoretically required at least a 21-stage separation.Furthermore,for the seawater sample separation experiments,the separation factor of uranium and sodium ions was 1.2885;therefore,more than 28 stages of sample separation would be required to achieve uranium extraction from seawater.The novel pulsed liquid chromatography method proposed in this study was innovative in terms of uranium separation and enrichment,while expanding the possibilities of extracting uranium from seawater through chromatography.
基金This work was supported by“National Key Research and Development Program of China”(Project No.2018YFC1603400)Science and Technology Program of Hebei Province(Project No.19225503D).
文摘The aim of this work was to develop an automated on-line solid phase extraction(SPE)with liquid chromatography-tandem mass spectrometry method for the detection of fifteen sulfonamides in pork and fish samples.Samples were extracted with 0.2%formic acid acetonitrile solution,purified by on-line SPE device with HLB column,then separated by XBridge C18 column,using 0.1%formic acid solution and acetonitrile as the mobile phase.Mass spectrometric data was acquired under multiple reaction monitoring(MRM)mode using positive ionization electrospray.Internal standard method was used in the quantification,good linear relationship was got in range of 0.1–100 ng/mL and correlation coefficient was higher than 0.9990.The limits of detection were in the range of 0.125–2.00g/kg and the limits of quantitation were in the range of 0.250–5.00g/kg.Recoveries of the method were in range of 78.3%–99.3%,relative standard deviation were lower than 10%.The method was simple,sensitivity,and could be used for routine supervision and analysis of fifteen sulfonamides in pork and fish.
文摘An isocratic reversed-phase liquid chromatographic (LC) method is described for the determination of epalrestat and its three stereoisomers (degradation impurities) in drug substance. The LC separation system consisted of a Hypersil C18 column (250 mm×4.6 mm, 5 μm) with a mobile phase comprising methanol, acetonitrile and water (volume ratio 60∶1∶50, pH 4.5) delivered at a flow rate of 1.6 mL/min and UV detection at 280 nm. The proposed LC method is simple and selective for the determination of the stereoisomers of epalrestat in the drug substance with a limit of detection and quantification of 3.9 μg/mL and 4.9 μg/mL, respectively. The stereoisomers were identified by liquid chromatography-mass spectrometry (LC-MS).
基金the supports of the National Key Research and Development of BioBased Rubber(2017YFB0306900&2017YFB0306901)the National Natural Science Foundation of China(51673012)+1 种基金the Fundamental Research Funds for the Central Universities(PYBZ1828)the Beijing Technology and Business Universtiy Youth Scholoars Funds(PXM2019014213000007)。
文摘Taraxacum kok-saghyz(TKS)is rich in natural rubber(NR),a natural organic macromolecular compound composed of cis-1,4-polyisoprene,and may become the second NR-bearing plant for biochemical engineering development.In this paper,a rapid and quantitative ultra-high performance liquid chromatography tandem mass spectrometry(UHPLCMS/MS)method was established for determination of macromolecular biosynthesis substrate(dimethylallyl pyrophosphate,DMAPP)and initiator(farnesyl pyrophosphate,FPP)contained in TKS.A Kromasil C18 chromatographic column was used for separation,and the multi-reaction monitoring mode(MRM)of triple quadrupole mass spectrometry was used for detection.Quantification was performed by external calibration method.The results showed that the limit of detection(LOD)and the limit of quantitation(LOQ)of DMAPP were 2.42μg/L and 7.26μg/L,respectively,and the LOQ and the LOD of FPP were 1.02μg/L and 3.05μg/L,respectively.At a concentration of 1—1000μg/L,both analytes had good determination coefficients(>0.999)of calibration curve.The recoveries of DMAPP and FPP were between 99.0%and 117.1%.In real samples detection,the contents of DMAPP and FPP in TKS samples were between 23.32—82.77μg/L and 12.03—85.67μg/L,respectively.Thus,this approach is a reliable method to quantify DMAPP and FPP in TKS.
文摘The measurement of urine catecholamine and metanephrine concentrations is important for biochemical screening and diagnosis of pheochromocytoma.The goal of this work was to develop a simple liquid chromatography-tandem mass spectrometry(LC-MS/MS)method for determining catecholamines and metanephrines in urine to replace an existing liquid chromatographic method using electrochemical detection.Urine samples were prepared using Oasis weak-cation-exchange cartridges.The eluate was analyzed on an Agilent ZORBAX Eclipse Plus Phenyl-Hexyl column in 3 min.Adrenaline,noradrenaline,dopamine,metanephrine,normetanephrine,and their deuterated internal standards were monitored in positive electrospray ionization mode by multiple reaction monitoring(MRM).No evidence of ion suppression was observed.The assay was linear up to 5μmol/L for adrenaline,5μmol/L for noradrenaline,6.1μmol/L for dopamine,5.6μmol/L for metanephrine,and 34.6μmol/L for normetanephrine,with lower limits of quantification of 5,5,12,6 and 7nmol/L,respectively.The intra-day and inter-day precisions for all analytes ranged from 0.59%to 4.64%and1.98%to 4.80%,respectively.External quality assurance samples were assayed and showed excellent agreement with the target values.This simple method provides an improved assay for determining urine catecholamines and metanephrines.
文摘A high-performance liquid chromatography was describ-ed to measure the concentration of human 3-methylhistidine in urine witho-phthaldialdehyde pre-column derivatization.This assay system resultedin a clear separation of 3-methylhistidine derivative from other derivativ-es in urine within 25 min.Linearity,recovery and coefficients of vari-ation were studied.The method has been successfully applied to routineanalysis for clinical studies and diagnosis.
文摘Chinese herbal compound is playing an important role on curing human diseases.And it has been a trend that Chinese herbal compound is being used all over the world in 21 century.However,our Chinese herbal compound is facing serious challenge for the lack of canonical system of quality criterion for Chinese herbal compound so it has been a urgent problem to set up the quality control standards and reveal therapeutic basis of Chinese herbal compound.In order to give full play to the advantages of Chinese herbal compound,modern scientific and technological is used to research of Chinese herbal compound,especially the high performance liquid chromatography tandem mass spectrometry(HPLC-MS),because it is high sensitive,rapid,and obtain more information.It is very necessary that HPLC-MS is uesed to elucidate the effective components of basic substances of Chinese Herbal Compound,and endow traditional Chinese medicine with modern scientific connotation.
基金Sponsored by the Basic Research Funds of Beijing Institute of Technology (20081642007)
文摘The method of reversed-phase high performance liquid chromatography was established for the determination of effective components in OC-CS spray using double wavelength UV detection.The method was utilized under following conditions:a column of Kromasil C18(250 mm × 4.6 mm,5 μm),mobile phase consisting of methanol/water(80 /20) at a flow rate of 0.8 mL/min,column temperature of 25 ℃,and the UV detection at 227 nm and 300 nm.Three key components in OC-CS spray could be distinguished clearly,including o-chlorobenzalmalononitrile(CS),oleoresin capsicum(OC) and dihydrocapsaicin(DC).This method has the advantages of fast,simple and satisfactory linear relationship between UV absorption and concentration.It may be considered to turn into a standard method for detection of related components in the spray.
文摘Modification was made on the reversed-phase high performance liquid chromatography(RP-HPLC)with Yue et al's method as a base.The modified RP-HPLC was used to detect leukotriene B_4(LTB_4)and 5-hydroxyeicosatetraenoic acid(5-HETE).It was found that the modified method has the merits of simpler procedures,shorter testing time and more satisfactory efficacy.
文摘After joining the faculty at Toyohashi University of Technology (TUT) in 1978, the author has found two areas in separation sciences where microcolumn liquid chromatography (micro LC) can be beneficial One is the hyphenated techniques between many spectroscopic methods such as mass (MS), infrared (FT IR) and atomic emission (ICP), and micro LC The other one is rather difficult, but basic and theoretical approach which deals with retention mechanism in LC The latter project has especially been giving him a lot of scientific funs and honors in the last 20 years On the occasion of being awarded by The Society for Chromatographic Sciences the author would like to summarize his contributions to this topic which asks us "What Is Chromatographic Retention?
文摘Liquid chromatography/mass spectrometry (LC/MS) is now considered to be the most promising analytical method for the determination of biological substances, especially nonvolatile or highly polar substances However, some compounds do not show enough sensitivity in LC/MS and soft ionization methods commonly used in LC/MS, such as electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI), sometimes do not give satisfactory structural information This report presents an overview of the derivatization methods in the LC/MS analysis of neurosteroids or neuroactive neurosteroids, which are synthesized and accumulated in the nervous system The derivatization of pregnenolone 3 sulfate, one of these steroids, with 4 ( N,N dimethylaminosulfonyl) 7 hydrazino 2,1,3 benzoxadiazole gave a satisfactory sensitivity during the quantitative analysis using LC/ESI MS The obtained results are much lower than those previously obtained using gas chromatography/mass spectrometry or radioimmunoassay On the other hand, the derivatization to acetate was useful for the treatment of labile catechol estrogens in rat brains and gave enough structural information in LC/APCI MS, which confirmed the existence of catechol estrogens in mammalian
基金supported by National Key Research and Development Program of China(2018YFC1603400)。
文摘A rapid method was presented for the determination of 19 polyphenols in tea by ultra-high performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry(UPLC-Q-TOF MS).Tea samples were extracted by 50%(V/V)ethanol,then separated by Waters Acquity BEH C18 column using a binary solvent system composed of acetonitrile and water(0.1%formic acid)by gradient elution.The analytes were determined by Q-TOF MS in TOF MS and information dependent acquisition(IDA)-MS/MS mode.The results showed that mass accuracy error of the 19 polyphenols were lower than 5.0×10^(-6),good linear relationship was got in range of 0.2–500μg/L and correlation coefficient was higher than 0.9990.The LOD was in the range of 0.002–0.100 mg/kg and the LOQ was in the range of 0.004–0.200 mg/kg.Recovery of the method was in range of 78.4%–109.2%with spike levels of 0.004–2.000 mg/kg,relative standard deviations were lower than 10%.The method was simple,rapid and accurate.It could be used for the rapid screening and quantitative analysis of 19 polyphenols in tea.
基金Supported by grants of the National Institute of General Medical Sciences,National Institutes of Health(GM-48364),and the Materials Sciences and Engineering Division of the U.S.Department of Energy(DE-AC02-05CH11231).
文摘Modern porous monoliths have been conceived as a new class of stationary phases for high performance liquid chromatography(HPLC) in classical columns in the early 1990s and later extended to the capillary format.These monolithic materials are prepared using simple processes carried out in an external mold(inorganic monoliths) or within the confines of the column(organic monoliths and all capillary columns).These methods afford macroporous materials with large through-pores that enable applications in a rapid flow-through mode.Since all the mobile phase must flow through the monolith,the convection considerably accelerates mass transport within the monolithic separation medium and improves the separations.As a result,the monolithic columns perform well even at very high flow rates.The applications of monolithic capillary columns are demonstrated on numerous separations in the HPLC mode.
文摘Five thyreostats(TSs),namely tapazole,thiouracil,methylthiouracil,propylthiouracil,and phenylthiouracil,were determined in bovine urine using ultra-high performance liquid chromatography-tandem mass spectrometry(UHPLC-MS/MS)in positive electrospray ionization mode.Extraction and clean-up were achieved using a ChemElut cartridge with tert-butyl methyl ether,without a derivatization step.Separation was achieved on an Acquity UPLC SS T3 column.The mobile phase was acetonitrile and water containing 0.2%(v/v)formic acid.The mass spectrometer was operated in multiple reaction monitoring mode.Urine samples were spiked with TS solution at levels corresponding to 5,10,15,and 20μg/L.The accuracy(internal standard corrected)ranged from 92%to 107%,with a repeatability precision(relative standard deviation,RSD)less than 15%for all five analytes.The RSDs within-laboratory reproducibility was less than 26%.The decision limits(CCα)and detection capabilities(CCβ)were obtained from a calibration curve and were in the ranges of 3.1-6.1μg/L and 4.0-7.4μg/L,respectively.The CCαand CCβvalues were below the recommended concentration,which was set at 10μg/L.The results show that the described method is suitable for the direct detection of TSs in bovine urine.This method can also be used to determine TSs in porcine urine.
