Effect of Adulteration on Quality and Preliminary Risk Assessment of the Decoction Pieces of Farfarae Flos Based on the Determination of Hepatotoxic Pyrrolizidine Alkaloids by UHPLC–MS/MS

Abstract

Farfarae Flos (FF) is a frequently used traditional herbal medicine with outstanding antitussive actions. The adulteration of FF decoction pieces is common. This study aimed to study the effect of adulteration on the safety and quality of FF decoction pieces. The proportion of impurities was conducted by cone quartering method. A simple and accurate ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method was established to simultaneous determinate three pyrrolizidine alkaloids (PAs) as endogenous toxic compounds in FF. The traditional medicinal parts (flower bud), impurities (pedicel and rhizome) and unselected samples were determined respectively. The values of estimated daily intake (EDI) and margin of exposure (MOE) were used for risk assessment. Twenty batches of samples were collected from different habitats, and the proportion of impurities ranged from 17.51% to 41.27%. Pedicel and rhizome were the main impurities, accounting for more than 87.40% of the total impurities. The content of PAs in impurities was significantly higher. The EDI value range was 5.34 to 16.59 μg/kg bw/day, which was much higher than the standard safety value of 7.00 × 10⁻³μg/kg bw/day. The MOE values ranges for life long time and shorter exposure were 14.29 to 44.37 and 371.53 to 1153.63, respectively, indicating that at least 80% of the samples had safety risks. Correlation analysis showed that the proportion of adulterated impurities had significant correlation with the values of EDI and MOE. Adulteration of non medicinal parts may significantly increase the risk of medications of FF decoction pieces. This study provides an efficient methodology reference for the control of PAs and a basis for adulteration to affect the safety and quality of FF decoction pieces.