Laser Ablation for Nondestructive Sampling of Microplastics in Single-Particle ICP-Mass Spectrometry

• Published in: Analytical chemistry (Washington) Vol. 95; no. 50; pp. 18579 - 18586
• Main Authors: Van Acker, Thibaut, Rua-Ibarz, Ana, Vanhaecke, Frank, Bolea-Fernandez, Eduardo
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 19.12.2023
• Subjects: Ablation; Inductively coupled plasma; Laser ablation; Laser beams; Lasers; Mass spectrometry; Mass spectroscopy; Microfibers; Microplastics; Polymethylmethacrylate; Sampling; Transport processes
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/acs.analchem.3c04473

In this work, laser ablation (LA) was characterized as a method for sampling and introducing microplastic particles (MPs) into an inductively coupled plasma (ICP) for subsequent 13C+ monitoring using an ICP-mass spectrometer operated in single-event mode. MPs of different types (PS, PMMA, and PVC) and sizes (2–20 μm) were introduced intactly. The laser energy density did not affect the particle sampling across a wide range (0.25–6.00 J cm–2). Single-shot analysis separated clustered MPs (2–7 MPs per cluster) during the LA and particle transport processes, allowing the temporally resolved analysis of the individual constituting MPs. Line scanning showed superior performance when using a small laser beam diameter combined with a high repetition rate. The 13C+ signal intensity correlated linearly (R 2 >0.9945) with the absolute C mass in a 2–10 μm size range, while the use of He in the collision-reaction cell (CRC) allowed extension of the linear range to 20 μm. The LA approach generated narrower 13C+ signal distributions than the traditional solution-based approach (dry versus wet plasma conditions) and proved successful for the analysis of a mixed suspension (containing four sizes of PS MPs in a 2–5 μm size range) and for sampling MPs from PVDF and glass microfiber filters, with the latter offering a lower background.