Lee Janghyeon, Lim Si-Hyung
Department of Mechanics and Design, Kookmin University, Seoul 02707, Korea.
School of Mechanical Engineering, Kookmin University, Seoul 02707, Korea.
Sensors (Basel). 2019 Aug 26;19(17):3706. doi: 10.3390/s19173706.
Gas chromatography (GC) is the chemical analysis technique most widely used to separate and identify gas components, and it has been extensively applied in various gas analysis fields such as non-invasive medical diagnoses, indoor air quality monitoring, and outdoor environmental monitoring. Micro-electro-mechanical systems (MEMS)-based GC columns are essential for miniaturizing an integrated gas analysis system (Micro GC system). This study reports an open-tubular-type micro GC (μ-GC) column with internal bump structures (bump structure μ-GC column) that substantially increase the interaction between the gas mixture and a stationary phase. The developed bump structure μ-GC column, which was fabricated on a 2 cm × 2 cm μ-GC chip and coated with a non-polar stationary phase, is 1.5 m-long, 150 μm-wide, and 400 μm-deep. It has an internal microfluidic channel in which the bumps, which are 150 μm diameter half-circles, are alternatingly disposed to face each other on the surface of the microchannel. The fabricated bump structure μ-GC column yielded a height-equivalent-to-a-theoretical-plate (HETP) of 0.009 cm (11,110 plates/m) at an optimal carrier gas velocity of 17 cm/s. The mechanically robust bump structure μ-GC column proposed in this study achieved higher separation efficiency than a commercially available GC column and a typical μ-GC column with internal post structures classified as a semi-packed-type column. The experimental results demonstrate that the developed bump structure μ-GC column can separate a gas mixture completely, with excellent separation resolution for formaldehyde, benzene, toluene, ethylbenzene, and xylene mixture, under programmed operating temperatures.
气相色谱法（GC）是最广泛用于分离和鉴定气体成分的化学分析技术，已广泛应用于各种气体分析领域，如无创医学诊断、室内空气质量监测和室外环境监测。基于微机电系统（MEMS）的气相色谱柱对于集成气体分析系统（微型气相色谱系统）的小型化至关重要。本研究报告了一种具有内部凸起结构的开管型微型气相色谱（μ-GC）柱（凸起结构μ-GC柱），该结构显著增加了气体混合物与固定相之间的相互作用。所开发的凸起结构μ-GC柱在2 cm×2 cm的μ-GC芯片上制造，并涂覆有非极性固定相，长1.5 m，宽150μm，深400μm。它有一个内部微流体通道，其中直径为150μm的半圆形凸起在微通道表面交替相对设置。制造的凸起结构μ-GC柱在17 cm/s的最佳载气速度下产生的理论塔板高度（HETP）为0.009 cm（11,110块塔板/m）。本研究中提出的机械坚固的凸起结构μ-GC柱比市售气相色谱柱和分类为半填充型柱的具有内部柱结构的典型μ-GC柱具有更高的分离效率。实验结果表明，所开发的凸起结构μ-GC柱能够在程序控制的操作温度下完全分离气体混合物，对甲醛、苯、甲苯、乙苯和二甲苯混合物具有出色的分离分辨率。
