Rapid fingerprint analysis based on supercritical fluid chromatography for quality evaluation of Hedyotis diffusa

In this study, quality evaluations of Hedyotis diffusa (H. diffusa) batches by rapid fingerprint analysis based on supercritical fluid chromatography (SFC) were accomplished. Abundant chemical components of H. diffusa were effectively extracted by optimal supercritical fluid extraction conditions (20 % MeOH as modifier, 45 °C, 300 bar and 60 min). Then, the extract was separated by SFC on a Torus 1-AA column (100 × 3.0 mm i.d., 1.7 µm) within 10 min by gradient elution increasing from 5 % to 45 % modifier (MeOH containing 0.05 % TFA) at 1.2 mL/min, 30 °C and 2000 psi. The SFC approach exhibited short analysis time, while maintaining good peak shape and resolution. Seven major compounds were further identified by SFC coupled with tandem mass spectrometer to be phenylpropanoid, iridoids and anthraquinones. Finally, fingerprint analysis of 10 batches of H. diffusa by the developed SFC method was accomplished. The similarity values were between 0.894 and 0.968, indicating quality differences of H. diffusa from depending on origin and harvest year exist. The result demonstrates the feasibility of the SFC in batch quality evaluation of H. diffusa.