Elemental mass spectrometry and Raman spectroscopy join forces to characterise single particles

David Clases

Nano- and microparticles are increasingly produced and emitted into the environment. Unfortunately, we continue to face difficulties to study their behaviour which are dependent on size, molecular and atomic composition as well as on number concentrations. This is anchored in the elusive nature of small particles and the requirement for very different analytical strategies to retrieve comprehensive and coherent information on a single particle level. As such, we fail to understand basic traits and their implications for human and environmental health.

The development and maturation of single particle inductively coupled plasma – mass spectrometry (SP ICP-MS) set a paradigm shift for the tracing and characterisation of particles. However, the pure “elemental” perspective provided through SP ICP-MS also obscures our vision at the nano-scale and we are blind for a considerable number of particles as well as properties.

This presentation will showcase new strategies to enable a comprehensive molecular and elemental characterisation of single particles (SP). Through the on-line coupling of two-dimensional optical traps, SP Raman spectroscopy and SP ICP-TOFMS, it becomes possible to carry out non-target screenings, to decipher the molecular and elemental composition of individual entities as well as to determine number concentrations and size distributions. The presentation will detail the underlying considerations and strategies and focus on new instrumentation, its hyphenation and future potential.

Literature:

• Neuper, M. Šimić, T. E. Lockwood, R. Gonzalez de Vega, U. Hohenester, H. Fitzek, L. Schlatt, C. Hill, D. Clases, “Optofluidic Force Induction meets Raman Spectroscopy and Inductively Coupled Plasma – Mass Spectrometry: A new hyphenated technique for comprehensive and complementary characterisations of single particles”, (2023) (10.26434/chemrxiv-2023-hwgll)
• E. Lockwood , R. Gonzalez de Vega, Z. Du, L. Schlatt, X. Xu, D. Clases, “Strategies to enhance figures of merit in ICP-ToF-MS”, J. Anal. At. Spectrom. (2024), 39, 227-234 (10.1039/D3JA00288H)
• R. Gonzalez de Vega, T. E. Lockwood, L. Paton, L. Schlatt, D. Clases, “Non-target analysis and characterisation of nanoparticles in spirits via single particle ICP-TOF-MS”, J. Anal. At. Spectrom. (2023), 38, 2656-2663, (10.1039/D3JA00253E)