| AVS 66th International Symposium & Exhibition | |
| Applied Surface Science Division | Tuesday Sessions |
| Session AS+BI+CA+LS-TuA |
| Session: | Beyond Traditional Surface Analysis |
| Presenter: | Yanyan Zhang, Institute of Chemistry, Chinese Academy of Sciences, China |
| Authors: | Y. Zhang, Institute of Chemistry, Chinese Academy of Sciences, China D.R. Baer, Pacific Northwest National Laboratory Z.H. Zhu, Pacific Northwest National Laboratory |
| Correspondent: | Click to Email |
Ion solvation plays very important roles in many important biological and environmental processes. Mass spectrometry (MS)-based methods have been used to investigate this topic with molecular insights. To study ion solvation, ionization processes should be as soft as possible in order to retain solvation structures. An in situ liquid secondary ion MS (SIMS) approach developed in our group has been recently utilized in investigations of Li ion solvation in nonaqueous solution, and it detected a series of solvated Li ions.[1] As traditionally SIMS has long been recognized as a hard ionization process with strong damage occurring at the sputtering interface, it is very interesting to study further how soft in situ liquid SIMS can be. In this work, we used halide ion hydration as a model system to compare the ionization performance of the in situ liquid SIMS approach with regular electrospray ionization MS (ESI-MS). Results show that, although ESI has been recognized as a soft ionization method, nearly no solvated halide ions were detected by regular ESI-MS analysis, and only strong signals of salt ion clusters were seen. As a comparison, in liquid SIMS spectra, a series of obvious hydrated halide ion compositions could be observed.[2] Our findings demonstrated that the in situ liquid SIMS approach is surprisingly soft, and it is expected to have very broad applications on investigation of various weak interactions and many other interesting chemical processes (e.g., the initial nucleation of nanoparticle formation) in liquid environment.
References:
[1] Zhang, Y.; Baer, D.; Zhu, Z.*, et al., “Investigation of Ion-Solvent Interactions in Non-Aqueous Electrolytes Using in situ Liquid SIMS”, Anal. Chem., 2018, 90, 3341–3348.
[2] Zhang, Y.; Zhu, Z.*, et al., “In Situ Liquid SIMS: A Surprisingly Soft Ionization Process for Investigation of Halide Ion Hydration”, Anal. Chem.2019, published online, DOI: 10.1021/acs.analchem.8b05804.