反相离子对色谱中有机溶剂浓度和离子对试剂浓度对保留值的影响

我们测定了氨基苯磺酸和氨基萘磺酸在反相离子对色谱中不同乙腈/水, 甲醇/水配比和离子对试剂浓度下的保留值,并把两种冲洗剂下的保留值和关系式lnk'=a+C~c~b中的参数a,C作线性关联,得到很好的相关性,这表明有机溶剂乙腈和甲醇对选择性并无显著的影响,但乙腈有更大的冲洗强度.证明关系式lnk'=A+Blnc~p+C~c~ b能较好地描述有机溶剂和离子对试剂浓度对保留值的影响, 但当离子对试剂浓度较高时该关系式不成立.同时提出了有机溶剂浓度和离子对试剂浓度"等同效应" 的概念

Comparison of aromatic sulphonic acids in reversed-phase ion-pair liquid chromatography with different organic modifier and ion-pair reagent concentration

The capacity factors of 15 aromatic sulfonic acids in reversed-phase ion-pair liquid chromatog. (RP-IPC) with acetonitrile/water and methanol/water containing ion-pair reagent tetrabutylammonium iodide were measured. The linear regression between the ln k' values and methanol, acetonitrile concns. according to equation ln k' = a + Ccb was carried out. Good linear relations of the ln k' values, the parameters a and C with acetonitrile as organic modifier vs. those with methanol as organic modifier were obtained, which mean that there is no significant difference in acetonitrile and methanol affecting the selectivity; the acetonitrile has a stronger eluent strength than methanol. The combined effect of organic modifier and ion-pair reagent concentration on retention values can be expressed by the equation ln k' = A + B ln cp + Ccb in a suitable range of ion-pair reagent concentration A crit. value the pos. effect of ion-pair reagent concentration on retention is the neg. effect of organic modifier concentration on retention was obtained.