线性非理想条件下液相色谱柱末端峰形规律

Peak Shape Distribution Rule of High Performance Liquid Chromatography in the End of Column Under Linear and Nonideal Conditions

色谱流出曲线的二阶中心矩μ２和三阶中心矩μ３以及描述峰形非对称程度的偏态系数∑ｋ＝μ３／μ１．５２是反映色谱峰形的重要参数。从液相色谱过程动力学方程出发，运用电子计算机证明了在线性非理想条件下高效液相色谱体系中不同保留值组分在柱末端峰形的分布基本一致的结论。

The central moments of chromatographic elution curve are important parameters for describing the column efficiency and chromatographic peak shape. According to the equation of chromatographic dynamics, we can get the second central moment and the third central moment of elution curve of HPLC under linear nonideal conditions. In our work, we investigated the relationships between second central moment, third central moment, coefficient of skewness of components distribution in the end of column and chromatographic column parameters, operation conditions, such as diameter of packing particle, desorption constant, diffusion coefficient in mobile phase, linear velocity of mobile phase, effect of extra column and so on. By means of computer, we discovered that there are no significant differences the second central moment, third central moment and coefficient of skewness for different components with different distribution coefficients. In the column end, therefore, different components have similar peak shape if there exist no obvious extra column effects. The column extra effect which stems from joint line and/or dead volume of detector is an important factor, causing column efficiency lower and peak shape tailing.