在线VOCs富集热脱附系统的研制及其应用

Development and application on online VOCs adsorption/thermal desorption system

研制开发了一套用于提高在线VOCs检测质谱仪灵敏度的在线VOCs富集热脱附系统。系统基于快速、精确的控温模块,采用大流量持续进样、双通路预浓缩模块转换交替的工作模式,满足与VOCs在线检测仪器联用的需求,且可以与常规离线技术的联用。采用苯系物标准气体对该系统的工作条件、富集能力、稳定性等性能参数进行了测试,同时考察了该系统在室内空气VOCs组分检测中的应用。结果表明:在线VOCs富集热脱附系统与在线VOCs检测质谱仪联用后,方法灵敏度提升了两个数量级;其次,与单独使用在线VOCs检测质谱仪相比,在线VOCs富集热脱附系统与在线VOCs检测质谱仪联用后可有效提高环境空气样品中痕量VOCs组分的检测能力。该系统为痕量VOCs气体检测等领域提供了一项新的检测技术。

An online VOCs adsorption/thermal desorption system was developed for enhancing the sensitivity of online VOCs mass spectrometry. By integrating a fast and precise temperature control module, a large flow rate sampling strategy and a switch mode pre-concentration module, the new system can be coupled to both online VOC detection instruments and offline ones. The performance of the system, such as operating conditions, enrichment capacity, stability, was tested by using a benzene series standard gas. Meanwhile the system was used to analyze the VOCs components in indoor air. The result show that the sensitivity of the online VOCs mass spectrometry was increased by two orders of magnitude. Secondly, compared to single online VOCs mass spectrometry, the system coupled to online VOCs mass spectrometry can greatly enhance the detectability of trace amount VOCs components in indoor air. This system will provide a new technology for trace VOCs gas detection.