APPLICATION OF COVALENT AFFINITY-CHROMATOGRAPHY WITH THIOL-DISULFIDE INTERCHANGE FOR DETERMINATION OF ENVIRONMENTAL EXPOSURE TO HEAVY-METALS BASED ON THE QUANTITATIVE ISOLATION OF CD-THIONEIN FROM HUMAN BREAST-MILK

The aim of this study was to test a new chromatographic method for the quantitative determination of Cd-thionein (Cd-Th) in human breast mil k, in order to determine the level of exposure to heavy metals. Cd-thi onein was isolated by covalent affinity chromatography with thiol-disu lphide interchange, which is a modern separation technique of high aff inity, good repeatability and reproducibility, allowing specific isola tion of the thiolproteins. The fundamentals of indirect determination of the contents of metallothionein protein from human milk were worked out through estimation of the quantities of cadmium bound with Cd-thi onein and adsorbed on covalent affinity chromatography gel during a se paration process. (C) 1998 John Wiley & Sons, Ltd.