Diperoxyazelaic acid as redox titrant. Part II. Potentiometric determination of N-acetylcysteine in ACC-100 pharmaceutical preparation

Abstract

A new redoх method for the quantitative determination of micro-quantities of N-acetylcysteinе (ACC) in the presence of ascorbic acid (AA), which is based on stoichiometrical and quantitative oxidation processes of analyzed analyte to the different products depending on pH medium generating by diperoxyazelaic acid in a situ iodine (triiodide) by the method of potentiometric titration was developed. A method is characterized by high sensitivity and sufficient accuracy and precision and also easy to perform. RSD was ≤1.62% (δ=0… 0.3%) for 1.63-3.26 mg ACC in the presence 1.76-3.52 mg AA in model solution. A method for determination of ACC in commercial samples (sachets) of famous pharmaceutical preparation ACC®100, that contain as antioxidant preservative of 12.5 mg ascorbic acid was proposed. The RSD was 1.02-1.61% (trueness, δ +0.33%... 0.44%).