Use of liquid chromatography‐tandem mass spectrometry for determination of higenamine in urine following oral administration of traditional Chinese medicine

Since higenamine (HG) was first included in the World Anti‐doping Agency (WADA) 2017 Prohibited List, an increasing number of plants have been found to contain this ingredient. As a result, doctors are hesitant to prescribe traditional Chinese medicine (TCM) to athletes. Thus, it is very important to assess the risks of doping violations due to HG following the oral administration of TCM. We determined the drug concentration‐time curves for HG in urine by liquid chromatography–tandem mass spectrometry (LC–MS/MS) after single or multiple administrations of lotus seed powder on volunteers, the single dose was equivalent to 750 μg of HG, and the multiple doses were equivalent to 90 μg of HG each, 3 times daily for 5 consecutive days. For the single‐dose group, the HG could be detected in urine 0.5 h after administration and reached a maximum concentration of 16.5 ng/mL 1 h after administration. For the multiple‐dose group, the HG concentrations in urine showed two peaks at 29 and 77 h post‐administration with 22.6 and 23.1 ng/mL, respectively. At the dosage used in this study, the maximum concentration of HG in some urine samples exceeded the WADA limit of 10.0 ng/mL; the risk was still very high, so athletes must avoid this amount of HG when using TCM. In addition, our study provided further data supporting the presence of sulfonated metabolites of HG in urine samples. The drug concentration‐time curves for higenamine (HG) in urine by liquid chromatography–tandem mass spectrometry after single or multiple administrations (3 times/day, 5 days) of lotus seed powder on 10 volunteers with a known HG content of 750 or 270 μg were determined, and sulfonated higenamine was detected; the presence of a sulfonated metabolite of HG in urine samples was further verified.