A Undergraduate Laboratory Innovating Project for Chiral Amino Acid Separation and Detection Using a Self-Made Low-Pressure Liquid Chromatography

Abstract The separation and detection of chiral compounds are fundamental yet often costly topics in organic chemistry education. To address these challenges, a self-made low-pressure liquid chromatography (SLLC) system was designed and implemented in an innovative laboratory project. The device, assembled from low-cost household items and a smartphone, was used to separate and detect l-phenylalanine obtained from a racemic mixture via diastereomeric salt crystallization. A synergistic strategy combining β-cyclodextrin as a chiral mobile-phase additive and pre-column derivatization with o-phthaldialdehyde/2-mercaptoethanol enabled real-time fluorescence detection using the smartphone’s light sensor. Students assembled the SLLC, performed the chiral resolution, and analyzed enantiomeric excess (ee) using the Phyphox app. The entire project was completed within six class hours at a cost of approximately 100 RMB (≈13 USD) per device. Feedback indicated increased engagement, deepened understanding of chromatography and chiral recognition principles, and enhanced confidence in hands-on experimentation. This approach provides a cost-effective, visually intuitive, and pedagogically robust method for teaching chiral separation in undergraduate curricula.