Qualitative and quantitative analysis of ephedrine stimulants in urine by ultra‐performance liquid chromatography–tandem mass spectrometry

Ephedrine analogues are stimulants that are explicitly required to be quantified and characterized in the Anti-Doping Prohibited List of the World Anti-Doping Agency. Given the difficulty of distinguishing diastereoisomers, the qualitative and quantitative analyses of ephedrine diastereoisomers are difficult.An ultra-performance liquid chromatography-tandem mass spectrometry (UHPLC/MS/MS) method was developed to detect five ephedrine analogues, and two pairs of diastereoisomers were identified using this method. The samples were analyzed qualitatively and quantitatively using a tandem mass spectrometer with an electrospray ionization source in multiple reaction detection mode after one-step dilution.The effective detection limits of this method were below 0.5 ng/mL. A matrix effect (range: 83.4% to 102%) was observed in quality control samples. The intra- and inter-day precision was lower than 9.16% and 8.60%, respectively, and the accuracy was within ±8.0%.The method is efficient, accurate, stable and sensitive, and fully meets the requirements for the detection of ephedrine substances in stimulants.