Isomers, holding similar chemical and physical properties, are difficult to separate especially by utilizing a microfabricated gas chromatography system due to limited column lengths mainly imposed by low-pressure (<20 kPa) micropump capability. In this paper, we demonstrated the separation of a pair of structural isomers, isopentane and pentane, in a micro-scale gas chromatography system with a circulatory loop of two 25-cm micro open tubular columns, while operating under a minimal pressure requirement of <10 kPa. The developed micro circulatory gas chromatography (MCGC) system achieved an effective column length of 12.5 meters by circulating the isomer gases for 25 cycles, the longest micro open tubular column length ever reported by any microfabricated GC systems yet.

具有相似化学和物理性质的异构体由于主要由低压（<20 kPa）微型泵功能引起的有限的色谱柱长度而难以分离，尤其是通过使用微型气相色谱系统。在本文中，我们证明了在具有两个25 cm微型开口管柱的循环回路的微型气相色谱系统中，在最小压力要求< 10 kPa。通过使异构体气体循环25个循环，已开发的微循环气相色谱（MCGC）系统达到了12.5米的有效柱长，这是迄今为止任何微型GC系统报告的最长的微开管柱长度。