“首项分裂”的进一步验证及所发现的异常峰形

Further Verifying on "First Term Splitting” and Abnormal Peak Shape Found in High Velocity of Carrier Gas

采用ＨＰ－５８９０Ａ气相色谱仪，ＨＰ－３３９２Ａ积分仪（工作在ＰＬＯＴ方式），配用长３０ｃｍ、内径０．５ｍｍ涂ＤＮＰ的铜毛细管柱，柱温１００℃，０．１μＬ正十四烷为样品，采用单池热导及氢焰检测器，通过改变流速再次验证了“首项分裂”现象。完成实验的关键是设法克服伴随进样过程产生的干扰。实验过程中再次发现了异常峰形。

First term splitting” is one type of peak splitting, which is deduced from “nonequilibrium plate theory”. Peak splits at very high flow rate, especially with a short column. The characteristic of the phenomenon for a single component is the appearing of two peaks in its chromatogram, a very narrow one located at the front of the mobile phase is called “first term peak” and another located slightly ahead of its normal place, “main peak”. In this work, the phenomenon was again verified by changing flow rate, with HP 5890A Gas Chromatograph and HP 3392A Integrator(at PLOT mode), copper capillary column(30cm×0.5mm i.d.) coated with DNP, at column temperature of 100℃, with both single cell TCD and FID and 0 1μL tetradecane as sample, The key of the experiment is to avoid the disturbance accompanied by the sampling process. It is also found some types of abnormal peak shape, which is supposed to be caused by high linear velocity of gas passing TCD.