Undergraduate Analytical Chemistry: Method Development and Results of the Analysis of Bismuth in Pharmaceuticals

Three different methods were developed and employed to analyze the concentration of bismuth subsalicylate in an oral liquid pharmaceutical suspension. These methods were UV-Visible spectroscopy utilizing the external calibration method and the standard addition method, flame atomic absorption spectroscopy, and complexometric titration with EDTA. All three methods were conducted within one 3-hr period by undergraduate students in analytical chemistry laboratory class settings and produced results within the allowable range of 90.0-110.0% as listed in the United States Pharmacopeia. Differences in sensitivity, precision, sample size, time, and reagent use between the three methods were observed.