New Dual-Technique Approach Advances Microplastic Detection at Single-Particle Level

A recent study published in the journal Talanta investigated how single-particle inductively coupled plasma–mass spectrometry (SP-ICP-MS) with optofluidic force induction coupled with Raman spectroscopy (OF2i-Raman) can overcome longstanding limitations in microplastic characterization.¹ This study was led by Svenja Seiffert of BASF SE and David Clases of the University of Graz, who we interviewed as part of our coverage of the 2026 Winter Conference in Plasma Spectrochemistry in Tucson, Arizona.

What are microplastics and why are they difficult to detect?

Microplastics are small plastic particles that are no more than 5 mm in size.² Because of their small size, and because they can predominantly be transparent, they are often hard to detect in water, soil, and air systems.² Some of the most common polymers found in microplastics include polyethylene, polyamide, and terephthalate.^2,3 The tendency of microplastics to co-exist with natural organic matter in environmental samples also make reliable identification difficult.¹ Current methods often struggle to distinguish plastic particles from other carbon-containing colloids, or to provide both mass and molecular identity from a single analysis.

What did the researchers do in their study?

In their study, the researchers used SP-ICP-MS to document carbon mass, particle size, and abundance during controlled UV-degradation experiments on two industrial polymers, polyamide-6 (PA-6) and low-density polyethylene (LDPE). The researchers found that SP-ICP-MS was able to successfully detect longitudinal mass loss and changes in particle populations as degradation progressed.¹ However, the authors noted that SP-ICP-MS was constrained by a narrow detectable size range and cannot differentiate polymer types because it measures total carbon only.¹

That is why the researchers used OF2i-Raman to identify polymer-specific spectral fingerprints for PMMA, polystyrene, PA-6, and LDPE.¹ Critically, it was also able to detect molecular-level structural changes caused by UV aging.¹ Together, the techniques link elemental mass data with molecular identity at single-particle resolution.

What work still needs to be done with OF2i-Raman and SP-ICP-MS in the detection of microplastics?

The authors acknowledge that SP ICP-MS currently remains suited to controlled laboratory conditions, whereas OF2i-Raman shows stronger potential for real-world environmental samples.¹ They frame the findings as a systematic benchmark rather than a proof-of-concept, positioning the combined approach as a practical framework for future microplastic research and environmental monitoring programs.¹

“SP-ICP-MS was useful to monitor mass, size and number-based changes of MPs in the low micrometer range during controlled UV-aging experiments of selected polymers,” the authors wrote in their study.¹ “However, SP ICP-MS analyses remain constrained by the narrow detectable size window and by the size-dependent transport efficiency.”

The researchers also noted that SP-ICP-MS was only able to detect total carbon, so it was unable to differentiate them from the other carbon-containing colloids. That’s where OF2i-Raman comes in.

“To overcome these limitations, an OF2i-Raman method was developed, which monitors the elastic and inelastically scattered light of single particles,” the authors noted in their study.¹

References

1. Candussi, M.; Neuper, C.; Gonzalez de Vega, R.; et al. Complementary Analysis of Pristine, UV-aged and Extracted Microplastics Using Single Particle ICP-MS and OF2i-Raman Spectroscopy. Talanta 2026, 302, 129339. DOI: 10.1016/j.talanta.2025.129339
2. Chen, J.; Chen, Y.; Peng, X. et al. Preliminary Study on the Distribution and Risk Assessments of Microplastic Pollution in Surface Water in Chengdu, China. Sci Rep. 2026. DOI: 10.1038/s41598-026-41638-5
3. Serranti, S.; Bonifazi, G.; Cocozza, P.; et al. Comparison of Hyperspectral Imaging and FTIR Spectroscopy for Microplastic Polymer Identification: Proposal of a Scalable Protocol Validated in a 12-Month River Survey. Talanta 2026, 129361. DOI: 10.1016/j.talanta.2026.129361