Undergraduate Laboratory Project Comparing Two Analytical Techniques for Ascorbic Acid Determination

We describe a project implemented in the honors section of an upper-level analytical chemistry undergraduate course, in which students designed an experiment to compare the performance of two analytical techniques to determine the amount of ascorbic acid in a commercial sample. This project designed for 18 students is composed of three stages. In the first stage, students investigate the fundamentals of the analytical techniques available for this lab, perform calculations similar to the ones they will use for data analysis, and propose an experimental procedure based on the physicochemical properties of the analyte reported in the literature. In the second stage of the project, students perform the measurements using a classical iodometric titration and one instrumental technique of their choice: cyclic voltammetry or spectrophotometry. In the final stage, students write a lab report in which they summarize their results and compare the techniques using appropriate statistical tests. In a survey conducted at the end of the project, students stated that investigating new analytical approaches, suggesting their own experimental approach, and implementing it in the lab had a positive impact on their scientific skills. Finally, this project enabled students to evaluate the merits of each technique for the determination of an analyte in a complex sample.