Development and validation of a supercritical fluid chromatography method for fast analysis of six flavonoids in Citri Reticulatae Pericarpium

The study is aimed to develop a rapid and efficient supercritical fluid chromatography coupled with diode-array detection (SFC-DAD) method for simultaneous quantification of six flavonoids in Citri Reticulatae Pericarpium (CRP). The chromatographic parameters including stationary phase, mobile phase composition, back pressure, temperature and flow rate, were systematically optimized with single-factor test. The results indicated that the six compounds were baseline separated on an Agilent Zorbax RX-SIL column using gradient elution within 10 min. The optimized mobile phase was constituted of carbon dioxide (CO2) and methanol. And the parameters were set as follows: backpressure, 95 bar; temperature, 45 °C; flow rate, 0.8 mL/min. The optimized method showed satisfactory retention and resolution for the analytes. The method was validated to demonstrate its selectivity, linearity, precision, accuracy and robustness. Thus, the verified SFC method was successfully applied to quantification of flavonoids present in CRP samples. The results indicated that SFC has the potential to become an excellent alternative for the analysis of flavonoids in herbal medicines, owning to its intrinsic features like high efficiency, separation speed and eco-friendly characteristics.