Detection of adulteration of anti-hypertension dietary supplements and traditional Chinese medicines with synthetic drugs using LC/MS

A sensitive and specific liquid chromatography-electrospray ionization mass spectrometry (LC/ESI-MS) method was developed for the analysis of 18 drugs used for the treatment of anti-hypertension, including diuretics, calcium antagonists, and angiogenesis-converting enzyme inhibitors (ACEI) as adulterants in dietary supplements and traditional Chinese medicines. Separation was accomplished on a Xtimate? C₁₈ reversed-phase column using a mixture of methanol, acetonitrile and 20 mM ammonium formate buffer (pH 3.2) as mobile phase. The method demonstrated linearity from 0.03 to 21.52 mg kg^?1. Limits of detection ranged from 6.5 to 86.0 µg kg^?1. The recoveries of spiked samples ranged from 71% to 109%. The procedure was successfully applied in routine inspection analysis.