VOCs在线检测质谱仪单光子电离源的研制

该文介绍了两个不同结构的真空紫外单光子电离源(SPI),电离源与自制的飞行时间质谱仪(TOFMS)连接实现了对挥发性有机物的在线检测。在搭建的SPI-TOFMS上比较了两个电离源的电离效率之间的差异。虽然轴向SPI本质上不是一个纯粹的单光子电离源,但可明显看出,其电离效率比径向SPI要高约50%。同时还考察了仪器的部分性能指标。在质荷比(m/z)为92位置,质量分辨率达767;在1谱/s分析速度下,检测限低于20×10-9(v/v)。实验结果证明该仪器能够用于挥发性有机物的在线检测。

Research on Single Photon Ionization Sources of Mass Spectrometer for On-line Detection of VOCs

Two vacuum ultraviolet single photon ionization(SPI)sources with different structures were introduced in this paper,and on-line detection of volatile organic compounds(VOCs)was realized by coupling the sources with a home-made time-of-flight mass spectrometer(TOFMS).The difference of ionization efficiency between the two sources was compared on the installed SPI-TOFMS.Obviously,the axial SPI,whose ionization efficiency was approximate 50% higher than the radical one,was not a pure SPI source in essence.Some performance indices of this instrument were also investigated at the same time.A mass resolution power of 767 was reached at location of mass-to-charge ratio(m/z)of 92;the limit of detection for toluene was 20×10-9(v/v)at the state of 1 spectrum/s analytical speed.It was demonstrated by the experimental results that this instrument can be using for on-line detection of VOCs.