呼气中痕量挥发性有机物的质子转移反应质谱在线检测研究

通过对自主研制的大气成分在线检测质子转移反应质谱的进样管路系统进行改造,建立了可在线检测呼气中痕量挥发性有机物的质子转移反应质谱装置。通过对呼气进样系统的旁路流量控制,实现对进样速度的调控,既可提高进样速度,以满足实时监测呼气中指定成分浓度变化;也可适时关闭旁路,以降低进样速度,从而对呼气成分进行全谱分析,避免采样袋采样和浓缩的复杂程序和潜在干扰。以作者呼出气体作为研究对象,对装置性能进行测试,结果表明:装置最快响应时间可达1s,对呼气中丙酮的探测灵敏度高达每10-9(V/V)浓度的信号强度为14.6counts/s,多次呼气测量重复性好,有望广泛应用于呼气疾病诊断研究。

Proton Transfer Reaction Mass Spectrometry for On-line Detection of Trace Volatile Organic Compounds in Breath

Based on the independently developed proton transfer reaction mass spectrometry(PTR-MS),a new tester of volatile organic compounds(VOCs) in breath was built.The by-pass flow rate in the breath sampling inlet is controlled by mass flow controller(MFC) in this breath tester.Not only can it monitor the concentration of the concerned VOCs in real time when the MFC is opening,but detect the VOCs with full mass scan when the MFC is closed.This avoids the potential effect from the sample bag and preconcentration.The breath gas of the first author was used as the sample gas to test the performance of breath tester.The result shows that the best response time of breath tester is 1 s,and the sensitivity for acetone in breath is 14.6 counts/s per 10-9(V/V).Its repeatability is also good.The breath tester holds a potential of a wide studies in the auxiliary medical diagnosis with breath.