Gholizadeh Azam, Chowdhury Mustahsin, Agah Masoud
VT MEMS Lab, Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, VA, 24061, United States.
VT MEMS Lab, Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, VA, 24061, United States.
J Chromatogr A. 2021 Jun 21;1647:462144. doi: 10.1016/j.chroma.2021.462144. Epub 2021 May 3.
This work highlights the effect of the stationary phase coating process on the separation efficiency of gas chromatography microcolumns. The stationary phase coating quality was characterized by three different bis(trifluoromethylsulfonyl)imide (NTf) anion based ionic liquids. The ionic liquids containing NTf anion are used for gas chromatography due to their high temperature stability. In this work, the chemical and physical approaches of column deactivation as well as the temperature treatment were evaluated by separating a mixture of 20 organic components and saturated alkanes. The results show that higher oven temperature treatment provides higher efficiency while losing a bit of peak symmetry. The thermal treated 1-butylpyridinum bis(trifluoromethylsulfonyl) imide [BPY][NTf] stationary phase at 240°C demonstrated as high as 8300 plates per meter for naphthalene. This was a 5-fold increase in separation efficiency in comparison to those of the columns treated at 200°C. Albeit being within acceptable ranges, the peak tailing degraded from 1.17 to 1.46 for naphthalene when the processing temperature for coating increased. Both chemical and physical deactivation process increased separation efficiencies and peak resolution.
这项工作突出了固定相涂覆过程对气相色谱微柱分离效率的影响。固定相的涂覆质量由三种不同的基于双（三氟甲基磺酰）亚胺（NTf）阴离子的离子液体来表征。含NTf阴离子的离子液体因其高温稳定性而用于气相色谱。在这项工作中，通过分离20种有机成分和饱和烷烃的混合物，对柱去活的化学和物理方法以及温度处理进行了评估。结果表明，较高的柱箱温度处理能提供更高的效率，但会损失一些峰对称性。在240°C下热处理的1-丁基吡啶双（三氟甲基磺酰）亚胺[BPY][NTf]固定相，萘的塔板数高达每米8300块。与在200°C处理的柱相比，分离效率提高了5倍。尽管在可接受范围内，但当涂覆处理温度升高时，萘的峰拖尾因子从1.17降至1.46。化学和物理去活过程都提高了分离效率和峰分辨率。
