This conventional method of Solid sample analysis is very dirty and produces a lot of
chemical waste. Conversely, laser ablation is a green technology because it does not require
acid dissolution and does not generate chemical wastes.
Moreover, LA-ICPMS technique presents other interesting features such as high spatial
resolution, extended linear dynamic range, low detection limits, extremely small sample
quantities required for analysis.
We propose an analytical strategy to enhance the sensitivity of LA- ICPMS by the
deposition of gold nanoparticles (AuNPs) on the surface of investigated samples. The
undoubted strengths of this approach are represented by simplicity, low-cost budget and fast
performance. The commercial LA-ICPMS set-up has not been changed in any way and laser
parameters, type and flow of gas carrier is not modified to improve the ablation of the sample
[1].
The sample surfaces have been altered by depositing metallic nanoparticle (NPs) colloidal
dispersions, thus increasing their response to laser, but preserving their chemical properties. A
consistent lowering of the breakdown threshold and a remarkable increase in the measured
signal intensity have been observed. This has allowed to determine traces and ultratraces in
many areas (environmental, forensic, clinical, cultural heritage, food analysis, ecc.).
In the method developed, the drops of NPs can be put in a controlled manner on the sample
surfaces and completely removed before the analysis by laser ablation. This represents a
further advantage compared to the classical methods of sample analysis.
The first results obtained with this technique in the analysis of metal matrices show
enhancement of the signal of one order of magnitude for most of the analyzed metals.
[1] Z. Wang, B. Hattendorf and D. Günther, J. Am. Soc. Mass Spectrom. 17 (2006) 641-651
