源后脉冲聚焦技术应用于气溶胶激光飞行时间质谱仪

Application of the Post-source Pulse-focusing Technique in Aerosol Laser Time-of-flight Mass Spectrometer

采用源后脉冲聚焦(PSPF)技术,极大地改善了气溶胶激光飞行时间质谱仪(ALTOFMS)系统的分辨率,在可聚焦的质量数范围内分辨率提高到原来的5.7倍。细致研究PSPF技术中的两个关键参数(脉冲电压延时和幅值),得到最佳的脉冲电压延时和幅值范围。采用多项式标定质量数,标定时的理论相对误差为10^(-4)～10^(-5)。PSPF-ALTOFMS现已应用于在线实时检测空气气溶胶粒子。

The post-source pulse focusing （PSPF） technique was used in a linear ALTOFMS. In its focused mass range, a mass resolution of a factor of 5.7 was achieved with the optimum parameters in our experiments. The influence of various experimental parameters, such as the delay time and the amplitude of the PSPF pulse on the performance of the instrument were discussed respectively. In addition, a new simple way, polynomial calibration, to calibrate mass number was discussed and the experimental relative error is 10^-4～10^-5. PSPF-ALTOFMS is used on-line to detect the indoor air particles.