Water determination in drugs containing thiols

A new rapid analytical method is applied for water determination in alpha-M ono-thioglycerol and Captopril tablets containing thiols, and therefore, no t amenable for direct Karl Fischer titration. The method is based on the co nsecutive titration first of thiol by a novel reagent, and then of water by a conventional K. Fischer reagent in the same sample and cell with the ele ctrometric 'dead-stop' location of the end point in both titrations. The ne w reagent consists of iodine, potassium iodide and sodium acetate in non-aq ueous medium. Estimated repeatability and accuracy of both water and thiol determinations are satisfactory. (C) 1999 Published by Elsevier Science B.V . All rights reserved.