含盐流动相损坏色谱柱原因探讨

Research on the Reason of Chromatography Column Damaged by Salt-bearing Mobile Phase

用高压液相色谱(HPLC)分析某种原料药的实验过程中,采用KH2PO4缓冲液(pH值6.5)和甲醇组成的流动相进行梯度洗脱时,连续损坏两根新的色谱柱。经柱外梯度洗脱模拟实验发现了原因:流动相pH值随着有机相在流动相中体积百分数的上升而上升,最终超过色谱柱允许的pH值上限而造成色谱柱的损坏;同时,当有机相的比例超过80%时,有磷酸盐晶体析出,堵塞色谱柱,这也是损坏色谱柱的另一原因。

A raw medical was analysed by high -pressure liquid chromatography （HPLC）, in which phosphate buffer （ pH value 6.5 ） and methanol was used as mobile phase by gradient elution, two new columns were damaged in this condition. The reason was found in an outside - column simulated test： The pH value of mobile phase was raised with the increase of organic phase ratio. At last , the pH value of mobile phase exceeded the permitted upper limit of the column and hurt the column. At the same time, it was also found that phosphate salt would crystallize when the organic phase ratio exceeded 80% o When the organic phase ratio was reduced to 10%, the same type column was used normally for 3 years.