Jump to main content
Jump to site search


Comparison of signal intensities and elemental fractionation in 257 nm femtosecond LA-ICP-MS using He and Ar as carrier gas

Abstract

The signal intensities and elemental fractionation at different ambient gas conditions (He, Ar and pre-mixed He-Ar mixture) were investigated using 257 nm femtosecond (fs)-LA-ICP-MS. The experiments show that the change of ablation carrier gases from argon to helium increases the sensitivities of refractory elements (e.g. rare earth elements) in NIST SRM 610 by a factor of 1.05-1.20. Whereas, the signal intensities of volatile elements (e.g. Tl, Cd, Se, Sn, Te, Zn, Pb, Bi, Ge, Ga, Sb, Ag, Cu) were increased by a factor of 1.5-3.0. The much less deposited aerosol particles around the ablation craters produced in helium when compared to argon may partly account for this phenomenon. Our results also suggest that volatile elements may enriched in small aerosol particles produced by femtosecond laser ablation whose transport efficiencies are increased when using He instead of Ar. The calculated elemental fractionation indices (with respect to Ca) of volatile elements (B, Cu, Zn, Ga, Ge, As, Cd, Mo, Ag, Sn, Sb, Pb and Bi) rapid increased to 1.1-1.2 with increasing the spot size from 24 μm to 60 μm when using helium as carrier gas. In contrast, they remain nearly constant at spot sizes of 24-60 μm when using argon as carrier gas. However, indices of volatile elements (Co, Ni, Cu, Zn, Ga, Ge, As, Ag, Cd, Sn, Sb, Pb, Bi) is less than 1 for all the spot sizes investigated. The signal intensities of all elements obtained in pre-mixed He-Ar mixture is similar to the sensitivities acquired in pure helium. Meanwhile, the calculated elemental fractionation indices for all elements generally remain constant and more close to 1 than in pure He or Ar at different spot sizes. The technique of using the pre-mixed He-Ar mixture as carrier gas has been successfully used for the determination of major and trace elements in USGS and MPI-DING glasses by using fs-LA-ICP-MS.

Back to tab navigation

Supplementary files

Publication details

The article was received on 21 May 2017, accepted on 05 Sep 2017 and first published on 05 Sep 2017


Article type: Paper
DOI: 10.1039/C7JA00190H
Citation: J. Anal. At. Spectrom., 2017, Accepted Manuscript
  •   Request permissions

    Comparison of signal intensities and elemental fractionation in 257 nm femtosecond LA-ICP-MS using He and Ar as carrier gas

    T. Luo, Q. Ni, Z. hu, W. Zhang, Q. Shi, D. Günther, Y. liu, K. Zong and S. H. Hu, J. Anal. At. Spectrom., 2017, Accepted Manuscript , DOI: 10.1039/C7JA00190H

Search articles by author

Spotlight

Advertisements