An improved high performance liquid chromatography-photodiode array detection-atmospheric pressure chemical ionization-mass spectrometry method for determination of chlorophylls and their derivatives in freeze-dried and hot-air-dried Rhinacanthus nasutus

► We develop HPLC-DAD-APCI-MS method for chlorophyll analysis in Rhinacanthus nasutus. ► 12 chlorophylls and their derivatives are identified and quantified in hot-air-dried sample. ► Only 4 chlorophylls found in freeze-dried sample, with chlorophylls a and b dominating. ► High recovery and reproducibility of chlorophylls and their derivatives are achieved.