Systematic Teaching Design and Practice of Liquid Chromatography-Mass Spectrometry Technology in Natural Product Chemistry Experiments

Building upon the existing experimental curriculum in natural product chemistry,this study introduces liquid chromatography-mass spectrometry (LC-MS) techniques through the development of following experimental modules:single quadrupole mass spectrometry was used to identify rutin via its M-H^- peak.Its purity was determined using a single-standard method.The M⁺,M+H⁺,and M+2H²⁺ peaks were used to identify berberine and berberine amine.Their purity was measured through an external standard method.Chrysophanol,rhein,and physcion is identified by quadrupole time-of-flight tandem mass spectrometry.Isomeric compounds,such as aloe-emodin and emodin,were distinguished based on fragmentation ion patterns in their secondary mass spectra.The instructional design of these experiments is problem-driven and systematically covers key LC-MS knowledge points,forming a progressively structured learning framework with distinct emphases.The new experimental modules integrate seamlessly with the original curriculum,effectively embedding LC-MS technology into undergraduate education and enhancing students' experimental competencies.