Preparation of an iminodiacetic acid-modified capillary and its performance in capillary liquid chromatography and immobilized metal chelate affinity capillary electrophoresis.

We prepared iminodiacetic acid (IDA)-modified and Cu(II)-IDA-modified capillaries through polymerization of N-(vinylbenzylimino) diacetic acid. The fundamental performance of these capillaries was examined in capillary liquid chromatography (LC) and immobilized metal chelate affinity capillary electrophoresis (IMACE). Copper(II), cobalt(II), and hematin were detected at different retention times by means of capillary LC with a chemiluminescence detector, during which the IDA-modified capillary was used. The difference in the retention times was attributed to the difference in the interaction between metal ions or complex and IDA moieties on the inner wall of the capillary. In addition, human serum albumin (HSA) and human serum gamma-globulin (HgammaG) were separated and detected using IMACE with an absorption detector, during which the Cu(II)-IDA-modified capillary was used. The separation of HSA and HgammaG was achieved through the interaction between proteins and Cu(II) chelate moieties on the inner wall of this capillary.