Influence of sample surface topography on laser ablation process

Zita Salajková; Markéta Holá; David Prochazka; Jakub Ondráček; David Pavliňák; Ladislav Čelko; Filip Gregar; Petr Šperka; Pavel Pořízka; Viktor Kanický; Alessandro De Giacomo; Jozef Kaiser

doi:10.1016/j.talanta.2020.121512

Influence of sample surface topography on laser ablation process

Talanta. 2021 Jan 15:222:121512. doi: 10.1016/j.talanta.2020.121512. Epub 2020 Aug 13.

Authors

Affiliations

¹ Materials Characterization and Advanced Coatings, Central European Institute of Technology, Purkyňova 656/123, Brno, Czech Republic; Department of Chemistry, University of Bari, Via Orabona 4, 70126, Bari, Italy. Electronic address: zita.salajkova@ceitec.vutbr.cz.
² Department of Chemistry, Masaryk University, Faculty of Science, Kamenice 735/5, 625 00, Brno, Czech Republic.
³ Materials Characterization and Advanced Coatings, Central European Institute of Technology, Purkyňova 656/123, Brno, Czech Republic; Faculty of Mechanical Engineering, Brno University of Technology, Technická 2, Brno, Czech Republic.
⁴ Department of Aerosol Chemistry and Physics, Institute of Chemical Process Fundamentals of the ASCR, Rozvojová 135, 165 00, Prague, Czech Republic.
⁵ Department of Physical Electronics, Faculty of Science, Masaryk University, Kotlářská 267/2, 611 37, Brno, Czech Republic.
⁶ Materials Characterization and Advanced Coatings, Central European Institute of Technology, Purkyňova 656/123, Brno, Czech Republic.
⁷ Institute of Machine and Industrial Design, Faculty of Mechanical Engineering, Brno University of Technology, Technická2896/29, 616 69, Brno, Czech Republic.
⁸ Department of Chemistry, University of Bari, Via Orabona 4, 70126, Bari, Italy.

PMID: 33167223
DOI: 10.1016/j.talanta.2020.121512

Abstract

In this work we discuss how sample surface topography can significantly influence the laser ablation (LA) process and, in turn, the analytical response of the LA Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) method. Six different surface topographies were prepared on a certified aluminium alloy sample BAM 311 and SRM NIST 610 to investigate the phenomenon. All the samples were repetitively measured by LA-ICP-MS using a spot by spot analysis. The effect of laser fluence in the range of 1-13 J/cm² was studied. For majority of measured isotopes, the ICP-MS signal was amplified with roughening of the sample surface. A stronger effect was observed on the Al alloy sample, where the more than sixty-time enhancement was achieved in comparison to the polished surface of the sample. Since the effect of surface topography is different for each analyte, it can be stated that surface properties affect not only the ICP-MS response, but also elemental fractionation in LA. The presented results show that different surface topographies may lead to misleading data interpretation because even when applying ablation preshots, the signal of individual elements changes. The utmost care must be taken when preparing the surface for single shot analysis or chemical mapping. On the other hand, by roughening the sample surface, it is possible to significantly increase the sensitivity of the method for individual analytes and supress a matrix effect.

Keywords: Fractionation; LA-ICP-MS; Laser ablation; Surface analysis; Surface topography.