Shaeen Chetty¹, Su-Ané Greyling¹, Letitia Pillay^1,

High-performance liquid chromatography (HPLC) is one of the most used analytical techniques for the identification and quantification of organic molecules in a variety of samples. In this simple laboratory experiment, quantification parameters and the factors affecting them were investigated using organic acids in plant material. Molar absorptivity (ε) and its implications on limit of detection (LoD) and limit of quantification (LoQ) were examined. Students prepared leaf samples by extraction and quantified the malic and fumaric acid concentrations based on calibration curves of a set of standards. Using the data the LoD, LoQ and ε were calculated and the implications of their values tested through a series of structured assessment questions. The learning goals include sample preparation, the application of theoretical calculations on method development, and calculating the organic acid concentrations. The experiment is suitable for senior undergraduate and early postgraduate students in analytical and environmental chemistry courses.

HPLC, organic acids, molar absorptivity, LoD, LoQ