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 0.06-0.17ppm. Adulterated steroids in three out of six real commercial liquid herbal medicines were found, such as 1.6 and 8.8ppm dexamethasone and 0.43ppm prednisolone.