Xie Xiaofeng, Dennis Tolley H, Lee Milton L
Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602, United States.
Department of Statistics, Brigham Young University, Provo, UT 84602, United States.
J Chromatogr A. 2017 Jun 16;1502:1-7. doi: 10.1016/j.chroma.2017.04.020. Epub 2017 Apr 26.
Rapid determination of trace level (parts-per-trillion) volatile organic compounds cannot always be achieved with conventional analytical techniques. In this study, a device was developed to sample a large volume of air in a short time period. The basic design involves packing sorbent layers concentrically around an empty permeable tube. Single digit parts-per-trillion detection limits were reached in less than 25min with this sampling system using gas chromatography-mass spectrometry for analysis. The concentric packed trap can sample at high flow rates (>10L/min) because it has a large sampling surface cross-section and short combined sorbent bed. Additionally, the large sorbent amount (>1g) provides large breakthrough volume (>100L) required to achieve low detection limits. The trapped analytes were thermally desorbed and transferred into a needle trap device for final analysis. This high flow sampling system was explored for detection of low ppt benzene, toluene, ethylbenzene and xylenes (BTEX) in air.
采用传统分析技术无法始终实现痕量水平（万亿分之一）挥发性有机化合物的快速测定。在本研究中，开发了一种能在短时间内对大量空气进行采样的装置。其基本设计是围绕一根空的渗透管同心填充吸附剂层。使用该采样系统结合气相色谱 - 质谱分析法，在不到25分钟内实现了个位数的万亿分之一检测限。同心填充捕集器能够以高流速（>10L/分钟）进行采样，因为它具有较大的采样表面横截面和较短的组合吸附剂床层。此外，大量的吸附剂（>1g）提供了实现低检测限所需的大穿透体积（>100L）。捕集到的分析物通过热脱附并转移到针阱装置中进行最终分析。本研究探索了这种高流速采样系统用于检测空气中低ppt浓度的苯、甲苯、乙苯和二甲苯（BTEX）。
