Determination of steroids adulterated in liquid herbal medicines using QuEChERS sample preparation and high-performance liquid chromatography

QuEChERS sample preparation was optimized using solvent extraction with acetonitrile and dispersive-solid phase extraction with primary and secondary amine sorbents, and validated for high-performance liquid chromatographic determination of nine steroids commonly used to adulterate herbal medicines: such as triamcinolone, prednisolone, hydrocortisone, methylprednisolone, betamethasone, dexamethasone, beclomethasone, fludrocortsone acetate and cortisone acetate. Satisfactory extraction recoveries of 91–113% for all nine steroids were obtained, along with an acceptable precision in extraction recoveries shown by R.S.D. of ≤4.6 and 3.2% for intraday and interday, respectively. The QuEChERS sample preparation developed here allows the reliable detection of adulterated steroids with the limits of detection in the range of 0.06–0.17 ppm. Adulterated steroids in three out of six real commercial liquid herbal medicines were found, such as 1.6 and 8.8 ppm dexamethasone and 0.43 ppm prednisolone.