The determination of blood glutathione by amperometric titration.

In 1946 Kolthoff and Harris devised a method of titrating mercaptans in aqueous alcoholic solution with silver nitrate. They used a rotating platinum electrode with suitable current measuring equipment to locate the titration end-point. Benesch and Benesch (1948) applied this technique to the determination of sulphydryl groups in serum protein, and Weissman, Schoenbach, and Armistead (1950) used the same method in a study of the sulphydryl content of albumin and globulin fractions in Connecting Wire normal sera. Since variations in the sulphydryl concentration of the blood are of interest to workers in the field of rheumatic diseases and to those concerned with diabetes, it was considered that a relatively simple method of estimating blood " glutathione " might usefully be evolved from an amperometric titration procedure. This proved to be correct. A description of the apparatus, an account of the technique, and of the results obtained, are now presented.