Crystallization and Solvent Evaporation Ionization Mass Spectrometry (CSEI-MS) for Rapid Detection of Drugs in Complex Matrices

Illegal addition of drugs is common but seriously threatens public health safety. Conventional mass spectrometry methods are difficult to realize direct analysis of drugs existing in some complex matrices such as seawater or soil due to the ion suppression effect and contamination to MS parts caused by nonvolatile salts. In this work, a novel crystallization and solvent evaporation ionization mass spectrometry (CSEI-MS) method was constructed and developed to achieve rapid desalting detection. CSEI only consists of a heated plate and a nebulizer and exhibits excellent desalting performance, enabling direct analysis of six drugs dissolved in eight kinds of salt solutions (up to 200 mmol/L) and three complex salty matrices. Under optimized conditions, CSEI-MS presents high sensitivity, accuracy, linearity, and intraday and interday precision. Finally, this method is applied to the quantitative analysis of drugs in seawater, hand cream, and soil. Furthermore, the highly sensitive detection of CSEI-MS is demonstrated to remain even if the detection processes are conducted within 5 s via common commercial tools.