Fusion and Solvent Evaporation Ionization Mass Spectrometry for Rapid Detection of Microplastics (MPs)

Microplastic (MP) pollution has gradually become a significant environmental concern, as MPs are widely present in soil, beaches, oceans, and even the atmosphere. Rapid detection and identification of MPs are crucial for monitoring and assessing environmental pollution. In this study, a fusion and solvent evaporation ionization (FSEI) device, comprising a heated plate and nebulizer, was developed for the direct detection and identification of six types of MPs. In the mass spectra, these MPs presented characteristic mass intervals corresponding to the monomer, realizing a more intuitive identification. After optimization, FSEI-MS demonstrated high sensitivity, good linearity (<i>R</i>² > 0.992), and accuracy (72.7-132.7%). Moreover, FSEI-MS realized discrimination of mixed MPs in terms of both time and spectra dimensions and was successfully applied to the detection of MPs in soil with good recoveries (82.6-117.5%, RSD < 13.2%). Furthermore, FSEI-MS overcame the environmental matrix interference and achieved the direct analysis of MPs in soil by utilizing a commercial spray bottle as the nebulizer. Overall, this research established a comprehensive methodology that integrates time-resolved and MS-based dimensions, offering a concise and efficient solution for MP analysis.