碱土金属和过渡金属离子在磺酸型阳离子交换树脂柱上以乙二胺-络合有机酸为流动相的保留行为

系统研究了碱土金属和过渡金属离子在磺酸型阳离子交换树脂柱上以乙二胺-络合有机酸(草酸、柠檬酸、酒石酸)为流动相的保留行为，比较了三种络合有机酸在洗脱和分离碱土金属和过渡金属离子时的差异，研究了流动相pH和乙二胺浓度对金属离子保留值的影响，流动相中络合有机酸的种类和浓度对碱土金属和过渡金属离子的选择性和分离均有影响，草酸和柠檬酸对过渡金属离子具有较好的选择性，以乙二胺一草酸或柠檬酸为流动相可以同时分离碱土金属和过渡金属离子，酒石酸对过渡金属离子的选择性差，用乙二胺一涵石酸作流动相可以分离碱土金属离子，但不适于分离过渡金属离子，当流动相中络合有机酸(草酸或柠檬酸)的浓度或pH(3.5～5.0)变化时，过渡金属离子保留值变化的幅度大于碱土金属离子，与此相应的会有碱土金属和过渡金属洗脱顺序的变化，这种差异可用于改善碱土金属与过渡金属离子之间的分离状况，改变流动相中乙二胺的浓度可以改变碱土金属和过渡金属离子的保留值，但它们的洗脱顺序不变。

RETENTION BEHAVIOR OF ALKALINE EARTH AND TRANSITION METAL IONS ON A SULFONIC CATION- EXCHANGE RESIN COLUMN WITH ETHYLENEDIAMINE - COMPLEX ORGANIC ACID AS MOBILE PHASE

Retention behavior of alkaline earth and transition metal ions on a sulfonic cation-exchange resin column with ethylenediamine-complex organic acid as mobile phase was studied. The elution and separation of alkaline earth and transition metal ions with three kinds of complex organic acid (oxalic, citric and tartaric acid) as mobile phase were compared. The effect of mobile phase pH and ethylenediamine concentration on retention value was investigated. The kind and concentration of complex organic acid influence the selectivity and separation of metal ions. The selectivity of transition metal is good with oxalic or citric acid. The simultaneous separation of alkaline earth and transition metal ions was achieved with ethylenediamine-oxalic or citric acid as mobile phase. When ethylenediamine-tartaric acid was used as mobile phase, the separation of alkaline earth was achieved, but the separation of transition metal ions was not success. When oxalic (citric) acid concentration or pH (3.5~5.0) of the mobile phase was changed, the variation of retention value of transition metal was greater than that of alkaline earth, and the order of elution for the ions was changed partly. The difference can be used to improve the separation between alkaline earth and transition metal ions. Varying concentration of ethylenediamine can change the retention value of alkaline earth and transition metal, but the order of elution for the ions can not be changed.