A method of aerosol introduction for matrix-assisted laser desorption/ionization （MALDI） is described. The aerosol particles containing matrix and analyte enter directly into the aerosol time-of-flight mass spectrom...A method of aerosol introduction for matrix-assisted laser desorption/ionization （MALDI） is described. The aerosol particles containing matrix and analyte enter directly into the aerosol time-of-flight mass spectrometer （ATOFMS） at atmospheric pressure. The scattered light signals from the aerosol particles are collected by a photomultiplier tube （PMT） and are passed on to an external electronic timing circuit, which determines particle size and is used to trigger a 266 nm pulsed Nd：YAG laser. The aerosol MALDI mass spectra and aerodynamic diameter of single particles can be obtained in real-time. Compared with other methods of liquid sample introduction, this method realizes detection of single particles and, more importantly, the sample consumption is lower. The effects of matrix-to-analyte ratio and laser pulse energy on analyte ion yield are examined. The optimal matrix-to-analyte ratio and laser energy are 50-110：1 and 200-400μl respectively.展开更多
Single aerosol particles were measured by matrix-assisted laser desorp-tion/ionization(MALDI)with an aerosol time-of-flight mass spectrometer(ATOFMS).The inlet to the ATOFMS was coupled with an evaporation/condensatio...Single aerosol particles were measured by matrix-assisted laser desorp-tion/ionization(MALDI)with an aerosol time-of-flight mass spectrometer(ATOFMS).The inlet to the ATOFMS was coupled with an evaporation/condensation flow cell that allowed matrix addition by condensation onto the particles.The coated particles entered the ion source through three-stage differentially pumped capillary inlet and were then ionized by a focused 266 nm Nd:YAG laser.The mass spectra and aerodynamic size of the single particles can be obtained simultaneously.The on-line matrix addition technique makes it possible to identify biological aerosols in real-time.展开更多
文摘A method of aerosol introduction for matrix-assisted laser desorption/ionization （MALDI） is described. The aerosol particles containing matrix and analyte enter directly into the aerosol time-of-flight mass spectrometer （ATOFMS） at atmospheric pressure. The scattered light signals from the aerosol particles are collected by a photomultiplier tube （PMT） and are passed on to an external electronic timing circuit, which determines particle size and is used to trigger a 266 nm pulsed Nd：YAG laser. The aerosol MALDI mass spectra and aerodynamic diameter of single particles can be obtained in real-time. Compared with other methods of liquid sample introduction, this method realizes detection of single particles and, more importantly, the sample consumption is lower. The effects of matrix-to-analyte ratio and laser pulse energy on analyte ion yield are examined. The optimal matrix-to-analyte ratio and laser energy are 50-110：1 and 200-400μl respectively.
文摘Single aerosol particles were measured by matrix-assisted laser desorp-tion/ionization(MALDI)with an aerosol time-of-flight mass spectrometer(ATOFMS).The inlet to the ATOFMS was coupled with an evaporation/condensation flow cell that allowed matrix addition by condensation onto the particles.The coated particles entered the ion source through three-stage differentially pumped capillary inlet and were then ionized by a focused 266 nm Nd:YAG laser.The mass spectra and aerodynamic size of the single particles can be obtained simultaneously.The on-line matrix addition technique makes it possible to identify biological aerosols in real-time.
