材料期刊网

近年来，分析工作者采用超高效液相色谱（ UPLC）完成了许多过去不能完成的分离分析工作。但是在阐述UPLC原理时不少人却采用了 van Deemter方程。这是不对的。本文研究了 UPLC 色谱过程动力学，从热传导方程出发运用色谱动力学原理推导了包括考虑流动相摩擦生热影响的 UPLC 塔板高度方程 H =2γD m／u+2λdpu1／3u1／3+ω（Dm／dp）1／3+2ku（1+k）2（1+κ0）kd +30θ（κ0+κ0k+k）2d2puDmκ0（1+κ0）2（1+k）2+κi（κ0+κ0k+k）2d5／3p u2／33κ0ΩD2／3m（1+κ0）2（1+k）2+ r20（κ0+κ0k+k）u4（1+k）Dr · exp（-Kr20α）。上述方程右端最后一项代表了流动相摩擦生热对塔板高度的贡献。当流动相线速度较低时，流动相摩擦生热对塔板高度的贡献趋近于零，塔板高度方程还原成 Horvath 和 Lin 的方程；当流动相线速度较高时，由于流动相摩擦生热，柱轴心与边缘温差增加，流动相线速度径向分布差异导致柱效率降低，而柱轴心与边缘的温差与流动相线速度平方成正比。作者明确指出：UPLC 的柱效率与柱内径密切相关，采用细内径柱有利于实现高效率；过高的流动相线速度将导致柱效率崩溃。

In recent years,separation and analysis workers have made considerable progress on ultra performance liquid chromatography( UPLC). A lot of separation works have been com-pleted which have never been done before. But the theory about chromatographic dynamics of UPLC from the beginning up to now,is remaining in 1950’s. Some people explain the principle of UPLC by the van Deemter equation,but this is not right. In this paper,the dynamic process of UPLC has been studied. According to the chromatographic dynamics principle and starting from the heat conduction equation,the plate height equation of UPLC including the influence of mobile phase friction heat production has been deduced as follows: H = 2γD m/u +2λdpu1/3u1/3+ω(Dm/dp)1/3 + 2ku(1+k)2(1+κ0)kd + 30θ(κ0+κ0k+k)2d2puDmκ0(1+κ0)2(1+k)2 + κi(κ0+κ0k+k)2d5/3p u2/33κ0ΩD2/3m(1+κ0)2(1+k)2 +r20(κ0+κ0k+k)u 4(1+k)Dr exp(-Kr20α). The last item on the right represents the contribution of mobile phase friction heat. When the linear velocity of mobile phase is lower,the contribution of mo-bile phase friction heat tending to become zero,the plate height equation is reduced to the Hor-vath and Lin equation. When the linear velocity of mobile phase is high,the temperature differ-ence between the column axial center and edge is directly proportional to the mobile phase line-ar speed square,and the contribution of thermal effect will largely increased. In this paper,the author clearly pointed out that the column efficiency of UPLC has a direct bearing on the col-umn diameter. Using fine diameter column is helpful to implement column efficiency. Too high mobile phase velocity will lead to the column efficiency collapsed.