氩微波等离子体炬作为气相色谱离子化检测器的研究

Studies on Argon Microwave Plasma Torch as Gas Chromatographic Ionization Detector

用氩气为工作气体的微波等离子体炬(ArMPT)作为气相色谱的离子化检测器,在优化实验参数的基础上,考察和对比了氧气或氮气分别作为ArMPT的屏蔽气体时,该检测器的响应特性及相应的离子化机理.研究结果表明,氧气作为ArMPT的屏蔽气体显示出更优的性能特性;重点测定了氧气作为ArMPT屏蔽气体时,该检测器对不同种类有机化合物的检出限.测定结果表明,该检测器对多数有机化合物的检出限为10-9～10-10g.该检测器具有运转费用低,可以在常压、低功率及低工作气体流量下安全稳定工作、操作简单方便等特点.对有机化合物的最大样品承受能力的对比结果表明,该检测器对有机化合物的最大样品承受能力明显优于surfatron和TM010等同类检测器,因而更有利于复杂样品中痕量组分的分析与测定.

In this paper, a microwave plasma torch (MPT) ionization detector for gas chromatography is studied while argon(Ar) is used as the plasma support gas. The response characteristics and the ionization mechanism when O2 and N2 were, respectively, used as the sheath gas of ArMPT are evaluated. It shows better response characteristics when oxygen is used as sheathing ArMPT than that when nitrogen is used. than nitrogen. The detection limit of organic compounds was also investigated. The detector could stably and easily work under the atmospheric pressure, with a lower cost, a lower power and a lower gas flowrate, moreover, the maximum endurance capacity of ArMPT to various organic compounds is superior to the similar detectors such as surfatron and TM010, thus it is helpful to the detection of the trace component in the complex mixtures.