高等学校化学学报

高等学校化学学报

• 研究论文 • 上一篇    下一篇

快速测量挥发性有机物的膜进样-飞行时间质谱仪的设计和应用

侯可勇1,3, 陈新华1,3, 董璨1,3, 李京华1, 姚琏2, 王海龙1, 王俊德1, 李海洋1   

    1. 中国科学院大连化学物理研究所, 大连 116023;
    2. 安阳工学院电气工程系, 安阳 455000;
    3. 中国科学院研究生院, 北京 100039
  • 收稿日期:2006-09-14 修回日期:1900-01-01 出版日期:2007-07-10 发布日期:2007-07-10
  • 通讯作者: 李海洋

Design and Application of Membrane Inlet-Time-of-Flight Mass Spectrometer for Rapid Analysis of Volatile Organic Compounds

HOU Ke-Yong1,3, CHEN Xin-Hua1,3, DONG Can1,3, LI Jing-Hua1, YAO Lian2, WANG Hai-Long1, WANG Jun-De1, LI Hai-Yang1*   

    1. Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China;
    2. Department of Electrical Engineering, Anyang Institute of Technology, Anyang 455000, China;
    3. Graduate School, Chinese Academy of Sciences, Beijing 100039, China
  • Received:2006-09-14 Revised:1900-01-01 Online:2007-07-10 Published:2007-07-10
  • Contact: LI Hai-Yang

PDF (PC)

被引次数

41

摘要：

研制了一种膜进样-微型飞行时间质谱仪, 该仪器使用双层50 μm硅橡胶膜作为大气压下直接进样的接口. 实验结果表明, 随着样品流速的提高, 膜富集效率信号强度呈线性提高. 双膜中间具有真空差分系统, 富集得到的样品被迅速抽走, 进样系统中样品无记忆效应. 样品在膜中的响应时间为100 s, 而打开差分系统后仅需10 s信号即下降为平稳状态. 与毛细管直接进样相比, 双层膜的富集作用显著, 在相同的实验条件下使用膜进样技术测定10×10-6 (体积分数)苯、甲苯和对二甲苯的信号强度分别提高了280, 370和600倍. 膜进样系统与真空紫外光软电离方式联用, 对于苯的检出限已经达到了25×10-9 (体积分数), 线性范围为3个数量级. 由于采用了软电离方法, 无碎片离子产生, 所以能够根据分子量进行快速定性分析. 将该仪器应用于香烟主烟气中可挥发性有机物的在线分析, 得到50多种可挥发性的有机物. 实验结果表明, 膜进样-飞行时间质谱将在在线分析(特别是环境监测)方面具有广泛的应用空间.

关键词: 膜进样, 飞行时间质谱仪, 快速分析, 软电离

Abstract:

This article describes a membrane inlet-miniature time-of-flight mass spectrometer. Double silicone sheet membranes with a thickness of 50 μm was used as interface for the atmospheric pressure direct sample inlet. The experimental result indicates that the enrichment factor of membrane is increased with the increase of the flow speed of the sample, and the signal intensity is almost linear with the gas flow. There is a vacuum differential system between the double membranes and the enriched sample is pulled out quickly, there is almost no memory effect in the membrane inlet system. The response time for benzene, toluene and o-xylene is about 100 s, but it only takes 10 s to get the steady condition after opening the vacuum valve. Comparing with the capillary sample inlet, the enrichment of double membrane is quite effective, the signal intensity for 10×10-6(volume fraction) benzene, toluene and o-xylene is enhanced 280, 370 and 600 times, when the membrane inlet was used under the same experimental conditions. Combining with vacuum ultraviolet soft ionization, the detection limit of the membrane inlet mass spectrometer is 25×10-9 (volume fraction) for benzene, and the linear dynamic range is about three orders of magnitude. The soft ionization is fragment free and qualitative analysis quickly according to the molecular weight of compounds. The instrument was used to on-line analyze volatile organic compounds (VOCs) in mainstream cigarette smoke, more than fifty compounds of VOCs on a mass spectrum were observed. The results indicate that the membrane inlet-time-of-flight mass spectrometer will be useful for a wide range of field application, particularly for environmental monitoring.

Key words: Membrane inlet, Time-of-flight mass spectrometer, Rapid analysis, Soft ionization

中图分类号: 

TrendMD: