分子印迹技术手性分离氨基酸衍生物(Ⅱ)—流动相对分子印迹聚合物手性拆分效果的影响

系统研究了乙腈流动相中甲醇、乙酸和水的体积分数变化对分子印迹聚合物手性拆分效果的影响。在流动相乙腈中添加较少量的甲醇或乙酸时〔φ(甲醇)≤8%,φ(乙酸)≤2%〕,随其体积分数的增加,手性分离效果提高;但当其体积分数继续增加,分离效果变差。以水作为添加物质时,当体积分数相对较少〔φ(H2O)≤30%〕,随其体积分数增加,手性分离效果变差;当水体积分数继续增加,拆分效果有所提高,在φ(H2O)=70%时,选择性因子达到1 52。降低流动相的pH值有利于手性拆分。利用梯度洗脱技术可以改善色谱分离中印迹分子洗脱峰的拖尾。

Chiral Separation of Amino Acid Derivatives by Molecular Imprinting Technique(Ⅱ)-Influence of the Components of Mobile Phase on the Chiral Separation

Influence of the components,such as methanol,acetic acid and H2O in the acetontrile mobile phase on the chiral separation of enantiomers was systematically investigated,and the mechanism of enantiomophous recognition was discussed.The results indicated that the enantiomophous recognition was improved with increase of methanol or acetic acid percentage in the mobile phase when the percentages of acetic acid and methanol were relatively low 〔φ(methanol)≤8%,φ(acetic acid)≤2%〕,but on continuously increasing the contents of those competitive substances,the effect of chiral separation was decreased.When the water percentage in the acetonitrile was relatively high, the effect of chiral separation became better.When the water percentage is 70%,the selective separation parameter is 152.It was found that the recognition was highly dependent on the pH of the water/organic mobile phase.Besides,the tailing and asymmetric eluted peak of solutes could be improved by using the gradient elution of the mobile phase.