Screening for Corticosteroid Adulterants in Korean Herbal Medicines

The objective of this study was to determine the presence of corticosteroids in illegal herbal medicines using ultra‐high‐performance liquid chromatography–tandem mass spectrometry. We collected 212 herbal medicine samples that were advertised as being effective for treatment of joint pain and bone aches. Samples were from the Korean commercial market during a span of four years (2010–2013), and the method was validated. The limits of quantification ranged from 0.47 to 15.0 ng/mL, and recoveries ranged from 80.6% to 119.5%. The intra‐ and interday precision ranged from 0.18% to 8.82% and from 0.09% to 8.96%, respectively. Among the samples, three samples (1.4%) were identified as adulterants. Dexamethasone was the only compound detected in the adulterated products. As the corticosteroid–adulteration of herbal medicines may become a major problem and lead to side effects, the continued development of screening procedures for herbal medicines is critical.