The anionic products from the reactions between metal（M=Ag, Au, Pd, Pt, Pb and Bi） vapour produced by laser ablation and hexafluorobenzene seeded in carrier gas（Ar） were studied by means of a homemade reflectron t...The anionic products from the reactions between metal（M=Ag, Au, Pd, Pt, Pb and Bi） vapour produced by laser ablation and hexafluorobenzene seeded in carrier gas（Ar） were studied by means of a homemade reflectron time-of-flight mass spectrometry（RTOF-MS）. Experimental results show that the dominant products were [MmC6F6]^- complexes for the reactions ofAg, Au, Pd and Pt with C6F6, while the dominant products were [MmC6F5]^- complexes for the reactions of Pb and Bi with C6F6. The formation mechanisms of the products, including the adsorption of metal cluster anions on hexafluorobenzene and the C--F cleavage induced by metal cluster anions, were discussed.展开更多
An apparatus based on collinear tandem time-of-flight mass spectrometer has been designed for the measurement of infrared photodissociation spectroscopy of mass-selected ions in the gas phase.The ions from a pulsed la...An apparatus based on collinear tandem time-of-flight mass spectrometer has been designed for the measurement of infrared photodissociation spectroscopy of mass-selected ions in the gas phase.The ions from a pulsed laser vaporization supersonic ion source are skimmed and mass separated by a Wiley-McLaren time-of-flight mass spectrometer.The ion of interest is mass selected,decelerated and dissociated by a tunable IR laser.The fragment and parent ions are reaccelerated and mass analyzed by the second time-of-flight mass spectrometer.A simple new assembly integrated with mass gate,deceleration and reacceleration ion optics was designed,which allows us to measure the infrared spectra of mass selected ions with high sensitivity and easy timing synchronization.展开更多
It is difficult to rapidly and on-line detect trace volatile organic compounds for miniature massspectrometry due to its limited sampling volume at slow pumping speed. In this paper, we developed anew radiofrequency f...It is difficult to rapidly and on-line detect trace volatile organic compounds for miniature massspectrometry due to its limited sampling volume at slow pumping speed. In this paper, we developed anew radiofrequency field enhanced chemical ionization source （RF-ECI） with vacuum ultraviolet （VUV）lamp by coupling radiofrequency electric field and direct-current field together. The experiment resultsshowed that the sensitivity of benzene, toluene, hydrogen sulfide and other compounds increased by 2-3orders of magnitude under the introduction of RF-ECI comparing to traditional single photon ionization（SPI）. At the same time, the reagent ion of O2＋ realized the charge transfer reaction chemical ionization,and the RF-ECI effectively expanded the detection range of the VUV lamp based SPI. The VUV lamp hasinherent advantages in the on-site analytical instrument for its small size and low power consumption,and the VUV lamp based RF-ECI miniature time-of-flight mass spectrometer （TOFMS） has a limit-of-detection for H2S as low as 0.0571 mg/m3, and it is expected to be used widely in the field of on-site rapidanalvsis.展开更多
研制了真空紫外灯单光子电离源飞行时间质谱仪(Vacuum ultraviolet single photon ionization timeof-flight mass spectrometer,VUV-SPI-TOFMS),包括真空系统、毛细管进样系统、真空紫外灯电离源、垂直加速反射式飞行时间质量分析器和...研制了真空紫外灯单光子电离源飞行时间质谱仪(Vacuum ultraviolet single photon ionization timeof-flight mass spectrometer,VUV-SPI-TOFMS),包括真空系统、毛细管进样系统、真空紫外灯电离源、垂直加速反射式飞行时间质量分析器和数据采集系统等。仪器采用的真空紫外单光子电离方式,能够将电离能低于紫外单光子能量(10.6eV)的挥发性有机物(Volatile organic compounds,VOCs)电离。与电子轰击源比较,紫外光电离基本无碎片产生,比较适合样品定性分析。结果表明,仪器的质量分辨率优于800(Fullwidth at half maximum,FWHM),质量精度优于1.0×10-4。仪器能够检测出香烟主流烟气中的60多种化合物,对于丙酮、环己烷、乙酸乙酯和甲苯的定性检出限分别为0.33×10-6,0.27×10-6,0.42×10-6和0.11×10-6。本仪器能够实现对各种环境介质(气相、固相、液相)中挥发性有机物的实时、在线检测,若与膜富集、加热进样装置或吹扫捕集系统联用,仪器的灵敏度能得到有效提高。展开更多
Ultra performance liquid chromatography(UPLC) coupled with orthogonal acceleration time-of-flight(oaTOF) mass spectrometry is becoming an effective and high-throughput analytical technique in metabonomics research.In ...Ultra performance liquid chromatography(UPLC) coupled with orthogonal acceleration time-of-flight(oaTOF) mass spectrometry is becoming an effective and high-throughput analytical technique in metabonomics research.In this paper,an UPLC-oaTOF-MS system was employed to investigate the serum profiles of 40 diabete mellitus(DM)/diabetic nephropathy(DN) patients and 25 healthy volunteers in an effort to find potential biomarkers.The UPLC system produced information-rich chromatograms with typical measured peak widths of 4 s,and generated peak capacities of 225 in 15 min.After the UPLC-oaTOF-MS analysis,principal component analysis(PCA) was used for group differentiation and marker selection.In the projection of positive mode,DM/DN patients and the controls were obviously divided into three groups.Furthermore,two potential markers were identified as phytosphingosine and sphinganine,respectively.Phytosphingosine and sphinganine with decreased concentrations in the patients,were closely related to the sphingolipid metabolism.展开更多
基金Supported by the National Natural Science Foundation of China(No.20433080).
文摘The anionic products from the reactions between metal（M=Ag, Au, Pd, Pt, Pb and Bi） vapour produced by laser ablation and hexafluorobenzene seeded in carrier gas（Ar） were studied by means of a homemade reflectron time-of-flight mass spectrometry（RTOF-MS）. Experimental results show that the dominant products were [MmC6F6]^- complexes for the reactions ofAg, Au, Pd and Pt with C6F6, while the dominant products were [MmC6F5]^- complexes for the reactions of Pb and Bi with C6F6. The formation mechanisms of the products, including the adsorption of metal cluster anions on hexafluorobenzene and the C--F cleavage induced by metal cluster anions, were discussed.
基金supported by the Ministry of Science and Technology of China(2013CB834603,2012YQ220113-3,and 2011YQ06010003)the National Natural Science Foundation of China(21273045 and 20933030)the Committee of Science and Technology of Shanghai(13XD1400800)
文摘An apparatus based on collinear tandem time-of-flight mass spectrometer has been designed for the measurement of infrared photodissociation spectroscopy of mass-selected ions in the gas phase.The ions from a pulsed laser vaporization supersonic ion source are skimmed and mass separated by a Wiley-McLaren time-of-flight mass spectrometer.The ion of interest is mass selected,decelerated and dissociated by a tunable IR laser.The fragment and parent ions are reaccelerated and mass analyzed by the second time-of-flight mass spectrometer.A simple new assembly integrated with mass gate,deceleration and reacceleration ion optics was designed,which allows us to measure the infrared spectra of mass selected ions with high sensitivity and easy timing synchronization.
基金This work was supported by the National Natural Science Foundation of China(No.22273065 and No.21673158)Science&Technology Commission of Shanghai Municipality(14DZ2261100).
基金financially supported by the National Natural Science Foundation of China(Nos.21375129 and 21675155)
文摘It is difficult to rapidly and on-line detect trace volatile organic compounds for miniature massspectrometry due to its limited sampling volume at slow pumping speed. In this paper, we developed anew radiofrequency field enhanced chemical ionization source （RF-ECI） with vacuum ultraviolet （VUV）lamp by coupling radiofrequency electric field and direct-current field together. The experiment resultsshowed that the sensitivity of benzene, toluene, hydrogen sulfide and other compounds increased by 2-3orders of magnitude under the introduction of RF-ECI comparing to traditional single photon ionization（SPI）. At the same time, the reagent ion of O2＋ realized the charge transfer reaction chemical ionization,and the RF-ECI effectively expanded the detection range of the VUV lamp based SPI. The VUV lamp hasinherent advantages in the on-site analytical instrument for its small size and low power consumption,and the VUV lamp based RF-ECI miniature time-of-flight mass spectrometer （TOFMS） has a limit-of-detection for H2S as low as 0.0571 mg/m3, and it is expected to be used widely in the field of on-site rapidanalvsis.
文摘研制了真空紫外灯单光子电离源飞行时间质谱仪(Vacuum ultraviolet single photon ionization timeof-flight mass spectrometer,VUV-SPI-TOFMS),包括真空系统、毛细管进样系统、真空紫外灯电离源、垂直加速反射式飞行时间质量分析器和数据采集系统等。仪器采用的真空紫外单光子电离方式,能够将电离能低于紫外单光子能量(10.6eV)的挥发性有机物(Volatile organic compounds,VOCs)电离。与电子轰击源比较,紫外光电离基本无碎片产生,比较适合样品定性分析。结果表明,仪器的质量分辨率优于800(Fullwidth at half maximum,FWHM),质量精度优于1.0×10-4。仪器能够检测出香烟主流烟气中的60多种化合物,对于丙酮、环己烷、乙酸乙酯和甲苯的定性检出限分别为0.33×10-6,0.27×10-6,0.42×10-6和0.11×10-6。本仪器能够实现对各种环境介质(气相、固相、液相)中挥发性有机物的实时、在线检测,若与膜富集、加热进样装置或吹扫捕集系统联用,仪器的灵敏度能得到有效提高。
文摘Ultra performance liquid chromatography(UPLC) coupled with orthogonal acceleration time-of-flight(oaTOF) mass spectrometry is becoming an effective and high-throughput analytical technique in metabonomics research.In this paper,an UPLC-oaTOF-MS system was employed to investigate the serum profiles of 40 diabete mellitus(DM)/diabetic nephropathy(DN) patients and 25 healthy volunteers in an effort to find potential biomarkers.The UPLC system produced information-rich chromatograms with typical measured peak widths of 4 s,and generated peak capacities of 225 in 15 min.After the UPLC-oaTOF-MS analysis,principal component analysis(PCA) was used for group differentiation and marker selection.In the projection of positive mode,DM/DN patients and the controls were obviously divided into three groups.Furthermore,two potential markers were identified as phytosphingosine and sphinganine,respectively.Phytosphingosine and sphinganine with decreased concentrations in the patients,were closely related to the sphingolipid metabolism.
