Simultaneous determination of picroside I and picroside II in dietary supplements by high performance liquid chromatography with PDA detector

Abstract

Picroside I and picroside II are two compounds found in the Picrorhiza Kurroa plant, which have anti-cirrhosis, antioxidant, anti-inflammatory, fever, and asthma effects, etc. They are included in the ingredients of many dietary supplement products that help protect the liver and bile, prevent oxidation, etc. Therefore, determining the content of these two active ingredients in dietary supplements is necessary to evaluate product quality. In this study, highperformance liquid chromatography (HPLC-PDA) was used to simultaneously determine picroside I and picroside II in dietary supplements. The analytes in the samples were extracted with methanol for 60 min using a horizontal shaking technique. The extract was then filtered and determined by the HPLC–PDA method with the following conditions: C18 Column (250 mm x 4.6 mm; 5 µm) and a corresponding pre-column (3.9 mm x 5 mm; 5 µm), the mobile phase consists of a solvent mixture of acetonitrile and water according to the gradient program, detection wavelength 265 nm. The method has good specificity, the calibration curve of picroside I and picroside II has a linear coefficient R2 > 0.9999 and the repeatability and recovery meet the AOAC requirements. The method limits of detection (MDL) for these two substances were 4.3 mg/kg and 3.2 mg/kg, respectively. The method was applied to simultaneously determine picroside I and picroside II in 30 different dietary supplement products. The results detected analytes in 3 samples positive with picroside I and picroside II concentrations ranging from 98.8 to 148 mg/kg.