Analytical Sciences

Abstract − Analytical Sciences, 37(11), 1577 (2021).

Quantification of Cathinone Analogues without Reference Standard Using 1H Quantitative NMR
Yuxin ZHAO,*1,*2 Bo WU,*1,*3 Zhendong HUA,*2,*4 Peng XU,*2,*4 Hui XU,*1,*2 Wenbin SHEN,*5 Bin DI,*1,*2 Youmei WANG,*2,*4 and Mengxiang SU*1,*2
*1 School of Pharmacy, China Pharmaceutical University, No. 24 Tongjiaxiang Road, Nanjing 210009, P. R. China
*2 China Pharmaceutical University Joint Laboratory on Key Technologies of Narcotics Control, China National Narcotics Control Commission, No. 24 Tongjiaxiang Road, Nanjing 210009, P. R. China
*3 The Narcotic Control Division, Nanjing Municipal Public Security Bureau, Nanjing 210042, P. R. China
*4 Key Laboratory of Drug Monitoring and Control, Drug Intelligence and Forensic Center, Ministry of Public Security, No. 18 Dongbeiwang West Road, Beijing 100193, P. R. China
*5 Center for Instrumental Analysis, China Pharmaceutical University, No. 24 Tongjiaxiang Road, Nanjing 210009, P. R. China
Synthetic cathinones are a type of new psychoactive substances (NPS) that have been seriously abused. Owing to the rapid variation in their structures, the absence of reference standards poses a challenge in quantitative investigations. In this study, a 1H quantitative nuclear magnetic resonance (1H qNMR) method was established using maleic acid as the internal standard and the shared signal (i.e., the methylidyne hydrogen) on the parent synthetic cathinones structure as the quantitative peak. Taking 3-methoxy-2-(methylamino)-1-(4-methylphenyl)propan-1-one (mexedrone) as an example, this study optimized the acquisition parameters and conducted method validation, including an evaluation of the specificity, linearity, accuracy, precision, and robustness. Using this 1H qNMR method, the contents of mexedrone and its analogues, including 1-(3-chlorophenyl)-2-(ethylamino)-propan-1-one (3-CEC), 4-chloro-α-pyrroli-dinopropiophenone (4-Cl-α-PVP), 1-(3,4-methylenedioxy-phenyl)-2-propylamino-propan-1-one (propylone), and methcathinone, were obtained. The obtained results showed that the method was accurate, rapid, versatile, and can be used to address the qualitative and quantitative issues related to similar substances.