Using Capillary Electrophoresis to Determine the Purity of Acetylsalicylic Acid Synthesized in the Undergraduate Laboratory

Abstract

Capillary electrophoresis (CE), although a powerful analytical tool, has found only limited application in undergraduate laboratory study. In an effort to expose freshman and sophomore chemistry students to this technique, thereby giving them practical instrumental experience early in their careers, we propose to use CE in the analysis of student-synthesized acetylsalicylic acid (ASA). The synthesis of ASA from salicylic acid (SA) is a routine undergraduate laboratory, although students rarely have the opportunity to test the purity of their product. The CE method described herein provides students with a method to test purity and yield of their product and to determine the effect of aging on their sample. CE can accomplish this in a short period of time, with minimal disruption to the regular laboratory curriculum. Optimized separation conditions, limits of detection, and linear range for ASA and SA are also given.