Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA; Center for Wireless Integrated MicroSensing and Systems (WIMS(2)), University of Michigan, Ann Arbor, MI 48109, USA; Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI 48109, USA.
Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA; Center for Wireless Integrated MicroSensing and Systems (WIMS(2)), University of Michigan, Ann Arbor, MI 48109, USA.
J Chromatogr A. 2020 Jun 7;1620:461002. doi: 10.1016/j.chroma.2020.461002. Epub 2020 Feb 27.
Micro gas chromatography (µGC) is a technique developed for rapid, in situ analysis of volatile organic compounds (VOCs) for environmental protection, industrial monitoring, and toxicology. While reduced µGC size and power requirements allow for increased portability, the low moisture and oxygen resilience of current microcolumn technology result in increased peak broadening and tailing for humid samples, which necessitates the use of bulky helium or nitrogen carrier gas cartridges. Developing a microcolumn to address these deficiencies is desirable to improve µGC field performance and further reduce µGC system size. This paper reports the development and characterization of a microfabricated phosphonium ionic liquid (µIL) column and demonstrates separation of both polar and nonpolar compounds using this column via analyses of alcohols, chloroalkanes, aromatics, aldehydes, fatty acid methyl esters, and alkanes. The µIL column achieved operation at temperatures up to 345 °C for fatty acid methyl ester and alkane separation. Notably, all separations in this study used dry air as the carrier gas, showing that analysis of a diverse range of compounds was possible in the presence of oxygen. After exposure to dry air for 48 h at temperatures up to 220 °C, the µIL column's peak capacity was only degraded by 8.92%, which validated its long-term robustness against oxygen. The column's separation performance was not degraded by high moisture concentrations or long-term moisture exposure, also manifesting its robustness to moisture. The high temperature, moisture, and oxygen resilience of the µIL column enable more rapid separations in varying field environments without requiring additional µGC accessories (e.g., humidity filters and carrier gas cartridges). The µIL column is therefore expected to be useful for integration into future µGC devices.
微气相色谱（µGC）是一种为快速、原位分析挥发性有机化合物（VOCs）而开发的技术，用于环境保护、工业监测和毒理学领域。虽然µGC 的尺寸减小和功耗要求降低，从而提高了便携性，但当前微柱技术对低湿度和氧气的适应性较差，导致潮湿样品的峰展宽和拖尾增加，这需要使用体积庞大的氦气或氮气载气盒。开发一种能够解决这些缺陷的微柱，对于改善µGC 的现场性能和进一步减小µGC 系统尺寸是非常理想的。本文报道了一种微加工的膦离子液体（µIL）柱的开发和表征，并通过对醇、氯代烷烃、芳烃、醛、脂肪酸甲酯和烷烃的分析，展示了该柱在分离极性和非极性化合物方面的性能。该µIL 柱可在高达 345°C 的温度下操作，用于脂肪酸甲酯和烷烃的分离。值得注意的是，本研究中的所有分离都使用干燥空气作为载气，表明在存在氧气的情况下，也可以对各种化合物进行分析。该µIL 柱在高达 220°C 的温度下暴露于干燥空气 48 小时后，其峰容量仅下降了 8.92%，这验证了其长期对氧气的稳定性。该柱的分离性能不受高湿度浓度或长期湿度暴露的影响，也表现出对湿度的稳定性。µIL 柱在高温、高湿度和高氧气环境下的适应性，使其能够在不同的现场环境中进行更快速的分离，而无需额外的 µGC 附件（例如湿度过滤器和载气盒）。因此，µIL 柱有望集成到未来的 µGC 设备中。
