Department of Chemistry, Tsinghua University, Beijing 100084, PR China.
Talanta. 2011 Oct 15;85(5):2458-62. doi: 10.1016/j.talanta.2011.07.097. Epub 2011 Aug 5.
A simple-structure, low-power, and low-cost low temperature plasma (LTP) ionization source, coupled with mass spectrometry, for the online detection of indoor volatile organic compounds (VOCs) has been constructed in this work. Air, instead of noble gases, was employed as the discharging and carrier gas. And a custom-built AC high-voltage power supply with a total power consumption of 5 W, frequency of 2-4 kHz, and amplitude around 1-5 kV(p-p) was used. This LTP source is a soft ionization source. The initial performance of the ionization source has been evaluated by ionizing samples including alcohols, ketones, aldehydes and aromatics. These compounds cover most of the common air pollutants concerning people's health. It is well known that those plasmas generated by dielectric barrier discharge (DBD) produce significant amount of metastable species and electrons with mean energies greater than several electronvolt, but minimal fragmentation was observed in our work. Protonated ions are the dominant product for the VOCs detected after the ionization process. Further work has been conducted to confirm the detection feature of this source. The results are promising enough to ensure the novel LTP ionization source as an effective tool for the online detection of indoor VOCs.
本工作构建了一种简单结构、低功耗、低成本的低温等离子体（LTP）电离源，并与质谱联用，用于在线检测室内挥发性有机化合物（VOCs）。空气而不是惰性气体被用作放电和载气。使用了一台定制的交流高压电源，总功耗为 5 W，频率为 2-4 kHz，幅度约为 1-5 kV（p-p）。该 LTP 源是一种软电离源。通过电离包括醇、酮、醛和芳烃在内的样品，评估了该电离源的初始性能。这些化合物涵盖了大多数与人们健康有关的常见空气污染物。众所周知，介质阻挡放电（DBD）产生的等离子体产生大量的亚稳态物种和平均能量大于几个电子伏特的电子，但在我们的工作中观察到最小的碎片化。在电离过程后，检测到的 VOCs 以质子化离子为主要产物。进一步的工作已经进行，以确认该源的检测特征。结果非常有希望，足以确保新型 LTP 电离源成为在线检测室内 VOCs 的有效工具。
