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Ephedrine and pseudoephedrine are stimulant drugs whose use is prohibited in athletic competition by the World Anti Doping Agency (WADA) at very different threshold doping violation concentrations. We use a recently developed universal approach that integrates UV photofragmentation spectroscopy of cold ions with Orbitrap mass spectrometry (MS) for highly selective and highly sensitive identification of these diastereomers. Both species can be selectively detected at a solution concentration of a few tens of ng/mL, which is almost 3 orders of magnitude lower than the threshold concentration required by WADA. Relative concentrations of the isomers in solutions have been determined with the standard deviation of 3.1%, when the ions were cooled in an ion trap maintained at T = 6 K. Considering practical implementation of the method, we evaluated its performance for a simplified instrumentation. At an affordable elevated temperature similar to 70 K and with a low-maintenance midbandwidth optical parametric oscillator, a few second measurement should yield nearly the same selectivity and only ten times lower sensitivity than with the current research grade instrument.
Julia Schmale, Ivo Fabio Beck, Benjamin Jérémy Laurent Heutte, Imad El Haddad, Hélène Paule Angot, Lubna Dada
Nicolas Lawrence Etienne Longeard
Jian Wang, Matthias Finger, Qian Wang, Yiming Li, Matthias Wolf, Varun Sharma, Yi Zhang, Konstantin Androsov, Jan Steggemann, Xin Chen, Rakesh Chawla, Matteo Galli, Anna Mascellani, João Miguel das Neves Duarte, Tagir Aushev, Tian Cheng, Yixing Chen, Werner Lustermann, Andromachi Tsirou, Alexis Kalogeropoulos, Andrea Rizzi, Ioannis Papadopoulos, Paolo Ronchese, Hua Zhang, Siyuan Wang, Tao Huang, David Vannerom, Michele Bianco, Sebastiana Gianì, Sun Hee Kim, Kun Shi, Abhisek Datta, Federica Legger, Gabriele Grosso, Ji Hyun Kim, Donghyun Kim, Zheng Wang, Sanjeev Kumar, Wei Li, Yong Yang, Geng Chen, Ajay Kumar, Ashish Sharma, Georgios Anagnostou, Joao Varela, Csaba Hajdu, Muhammad Ahmad, Ioannis Evangelou, Milos Dordevic, Meng Xiao, Sourav Sen, Xiao Wang, Kai Yi, Jing Li, Rajat Gupta, Zhen Liu, Hui Wang, Seungkyu Ha, Long Wang, Pratyush Das, Anton Petrov, Xin Sun, Valérie Scheurer, Giovanni Mocellin, Muhammad Ansar Iqbal, Lukas Layer