Separation of metallothionein into isoforms by column switching on gel permeation and ion-exchange columns with high-performance liquid chromatography-atomic-absorption spectrophotometry.

Metallothionein in tissue supernatant was separated into isoforms by on-line switching from gel filtration to ion-exchange columns and the metals bound to the isoproteins were directly determined by using a flame atomic-absorption spectrophotometer as a specific detector for metals. Conditions for elution of the gel filtration column were established and Tris-HCl buffer solutions in low concentration were shown to be applicable to the column-switching experiment. The effects of pH, buffer and salt concentrations on the elution of metallothionein are discussed.