Kinetic Potentiometric Determination of some Thiols with Iodide Ion‐Sensitive Electrode

This paper describes a kinetic potentiometric method for the determination of thiols (RSH): l‐cysteine (cys), N‐acetyl‐l‐cysteine (NAC), l‐glutathione (glu), and d‐penicillamine (pen). The proposed method is based on the reaction of formation the sparingly soluble salts, RSAg, between RSH and Ag+ ions. During this reaction potential‐time curves were recorded by using an electrochemical cell with commercial iodide selective electrode. The rectilinear calibration graphs are obtained in the RSH concentration range from 1.0×10−5 to 1.0×10−3 M. The applicability of the proposed method was demonstrated by determination of chosen compounds in pharmaceutical dosage forms.