Accuracy in quantitative analysis using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) depends on the availability of matrix-matched external calibration standards. While several certified reference materials have been developed, suitable standards for carbon-rich matrices, such as polymers and biological tissues, remain scarce. Consequently, many laboratories rely on in-house standards and carbon as an internal standard.[1]

However, earlier studies on the analysis of polymers by Todolí et al. (1998) and Frick et al. (2012) demonstrated that up to 80% of ablated carbon is transported in the gaseous phase[2], and that gaseous carbon species formation critically depends on the oxygen content of the sample matrix and the ablation environment.[3] Therefore, both studies were raising concerns about the reliability and suitability of carbon as an internal standard.
More recently, Van Helden et al. (2024) reported the formation of gaseous species for various elements upon laser ablation on a spiked gelatine sample.[4] They showed that gaseous species formation during LA is both element- and matrix-dependent and further modulated by instrumental parameters such as laser wavelength and fluence.

In this study, we extend these investigations by analyzing gaseous species formation across different sample matrices and instrumental conditions, with particular emphasis on the effect of laser pulse width. Both nanosecond (ns) and femtosecond (fs) lasers were employed. Gaseous and particulate fractions were separated using a Gas Exchange Device (GED), 0.2 µm Milipore filter and an elongated aerosol transport tube between the ablation cell and the ICP-MS. The temporal separation of gas and particle phases was investigated under different ablation cell designs and ablation gas compositions.

[1]  D. Pozebon, G. L. Scheffler and V. L. Dressler, J Anal At Spectrom, 2017, 32, 890–919.
[2]  J.-L. Todolí and J.-M. Mermet, Spectrochimica Acta Part B, 1998, 53, 1645–1656.
[3]  D. A. Frick and D. Günther, J Anal At Spectrom, 2012, 27, 1294–1303.
[4]  T. Van Helden, K. Mervič, I. Nemet, J. T. van Elteren, F. Vanhaecke, S. Rončević, M. Šala and T. Van Acker, Anal Chim Acta, 2024, 1287, 342089.