Sample preparation for determination of steroids dulterated in herbal medicines by high performance liquid chromatography

Abstract

QuEChERS sample preparation was optimized and validated for high-performance liquid chromatographic determination of nine steroids adulterated in liquid herbal medicines: triamcinolone, prednisolone, hydrocortisone, methylprednisolone, betamethasone, dexamethasone, beclomethasone, fludrocortsone acetate and cortisone acetate. In QuEChERS procedures, a liquid sample (2.0 ml) was first extracted with acetonitrile (2.0 ml) in the presence of anhydrous magnesium sulfate (500 mg) and sodium chloride (125 mg). The sample cleanup was then performed by dispersive-solid phase extraction using primary secondary amine sorbents (50 mg) as well as magnesium sulfate for the removal of residual water. Satisfactory extraction recoveries of 91113 % for all nine steroids were obtained, along with an acceptable intraday and interday precision in extraction recoveries shown by relative standard deviation of  3.4 %. 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 commercial herbal medicines were found, such as 1.6 and 8.8 ppm dexamethasone and 0.43 ppm prednisolone