Use of erythrocyte ghosts for preconcentration in element speciation

A totally new biosorption concept has been tested. It involves the use of a biological membrane with given transport characteristics that encloses a reaction compartment chosen to bind incorporated substances irreversibly. Such a system is an erythrocyte ghost: erythrocytes that are hypotonically lysed can be filled with the desired media and resealed by warming up for 1 h. The transport system exploited is the predominant one in erythrocytes, i.e., the anion transport system with 10(6) channels/cell. Erythrocyte ghosts (in the following simply called ghosts) filled with ascorbate or cysteine as intracellular reductants were compared to unmodified human erythrocytes with regard to their ability to accumulate chromate specifically. Furthermore, the lifetime and behavior of the ghosts with respect to the influence of extracellular Cr(III) were tested. The great similarity found between the ghosts tested and unmodified erythrocytes clearly shows the general applicability of this new biosorption concept which offers possibilities for the biosorption of analytes that cannot be accumulated by unmodified erythrocytes.