The combination of solid sample analysis by Laser Ablation with argon-based Inductively Coupled Plasma Mass Spectrometry (LA-ICPMS) for trace element analysis was introduced over 40 years ago.[1] Over these years, significant improvements were achieved ranging from the use of helium as carrier gas[2] to the measurement in 3-dimensions of elemental distributions using state-of-the-art fast washout ablation cells.[3] Yet, not every sample can be placed inside an air-tight ablation cell. Open ablation cells were developed to allow analysis of samples independent of their size and shape. However, these designs suffered from sample contamination due to the use of sealants or required a gas exchange device for online ICPMS measurement,[4] increasing the total gas consumption and the required hardware. Sampling methods for laser generated aerosol on filters was also developed using a portable setup, but its applications were restricted to off-line analysis,[5] requiring additional sample preparation and increasing the risk of contamination. Most of these drawbacks can now be circumvented with the recently introduced nitrogen-based high-power plasma source for ICPMS, which provides similar figures of merit as conventional argon-based ICPs, while reducing the operating costs significantly.[6]

Therefore, detailed characterization of nitrogen as an alternative carrier gas and its comparison to helium has been carried out[7] and will be presented including quantitative insights into the laser-induced fractionation. These fundamental considerations will be discussed in combination with the new possibilities offered by the nitrogen plasma source, including the current development of a novel portable laser ablation setup. These new applications will be described along with the evaluation of the operating conditions required for such on-line analyses in the field.

[1]   A.L. Gray, Analyst, 1985, 110, 551-556
[2]   S.M. Eggins, L.P.J. Kinsley, J.M.G. Shelley, Appl. Surf. Sci., 1998, 127-129, 278-286
[3]   M. Burger, A. Gundlach-Graham, S. Allner, G. Schwarz, H.A.O. Wang, L. Gyr, S. Burgener, B. Hattendorf, D. Grolimund, D. Günther, Anal. Chem., 2015, 87, 8259-8267
[4]   D. Tabersky, K. Nishiguchi, K. Utani, M. Ohata, R. Dietiker, M.B. Fricker, I.M. de Maddalena, J. Koch, D. Günther, J. Anal. At. Spectrom., 2013, 28, 831-842
[5]   M. Burger, R. Glaus, V. Hubert, S. van Willigen, M. Wörle-Soares, F. Convertini, P. Lefranc, E. Nielsen, D. Günther, J Archaeol Sci, 2017, 82, 62–71.
[6]   M. Schild, A. Gundlach-Graham, A. Menon, J. Jevtic, V. Pikelja, M. Tanner, B. Hattendorf, D. Günther J. Anal. At. Spectrom., 2018, 90, 13443-13450
[7]   D. Käser, R. Kägi, B. Hattendorf, D. Günther, J. Anal. At. Spectrom., 2024, 39, 3069-3071