Controlled-potential controlled-current electrolysis: In vitro and in vivo electrolysis of urea

Abstract

A controlled-potential, controlled-current (c.p.c.c.) method for electrolysis has been developed. Electrolysis is performed under controlled oxidative and controlled reductive currents within preset upper and lower bound potentials. The c.p.c.c. approach accomplishes both electrolysis and electrode regeneration concurrently. Compared with the existing galvanostatic and/or controlled potential electrolysis, the present approach demonstrates a greater selectivity for the electroactive species. The approach has been applied to direct electrolysis of urea in physiologic solutions and in recirculated canine hemodialysate. No undesirable, harmful, or toxic products have been found. The Pt-black electrodes, rejuvenated during the electrolysis, were found to perform as well in a standard test as they had prior to electrolysis of the hemodialysate. In view of its selective and regenerative nature, c.p.c.c. electrolysis is thought to be suitable for urea removal in a closed-loop, regenerative hemodialysis system. It is also most likely adapatable to other electrolyses of clinical substances.