人参皂甙的反相高效液相色谱多台阶梯度优化方法

建立了一种反相高效液相色谱多台阶梯度分离人参皂甙的方法.该方法以乙腈-水溶液为流动相,通过一系列等度实验,获得了8种人参皂甙Rg1,Re,Rf,Rg2,Rb1,Rc,Rb2和Rd的色谱保留参数,发现两参数保留方程不适合用于人参皂甙这种天然产物的分离条件的优化,而三参数保留方程的高精度才可满足预测的要求.在三参数保留方程的基础上,通过计算确定了8种人参皂甙(包括3台阶梯度)的液相色谱分离条件.通过实验对此优化条件进行了验证,实验结果显示了较好的预测精度和分离度.将本方法用于分离人参皂甙,分析时间短且分离度高,显示了等度台阶梯度优化方法对确定色谱分离条件的优越性.

Optimization Method of Multi-segment Gradient for Separation of Ginsenosides in Reversed Phase-High Performance Liquid Chromatography

A multi-segment gradient method for the separation of ginsenosides in reversed phase-high performance liquid chromatography(RP-HPLC) was developed. The retention parameters of 8 ginsenosides(Rg1, Re, Rf, Rg2, Rb1, Rc, Rb2 and Rd) were obtained on an ODS2 C18 column(4.6 mm×250 mm) from a series of isocratic acetonitrile-water elution. It is found that two-parameter retention equation of ginsenosides can′t be used to accurately predict the resolution, but the three-parameter retention equation can. The reason is that the retention factor k′ decreases fast while the volume fractions of acetonitrile increase in mobile phase, which make the precision of two-parameter retention equation can′t satisfy the predicting need of resolution. Based on the three-parameter retention equation, an optimum elution program consisting of three segments was developed. Under the optimized gradient conditions, the retention time and resolution of ginsenosides are in good agreement with the predicted ones. The analysis time of ginsenosides is shortened and the resolution is improved by the method.