Analysis of soil and sediment samples by laser ablation inductively coupled plasma mass spectrometry

Abstract

The analysis of soil and sediment samples using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS ) was studied. Solution-based calibration was used for the quantification of trace elements in these samples. In most cases, the measured concentrations were within ±20% of the certified values using 60Ni or 107Ag as the internal standard. Measurements with Ag were carried out to investigate whether an internal standard could be spiked into soils for quantification purposes. The influence of particle size on the applicability of sample spiking was briefly studied, and it was demonstrated that particle size could significantly influence measurements if only the surface constituents of the particle were ablated. Use of 43Ca or 44Ca as an internal standard produced poorer results owing to interferences at these masses. In some cases, such as with Sr, Ba, Y and Rb, the measured concentrations were low by a factor of 2-3. This could be remedied by using one of these elements as an internal standard for the others. The effects of elemental speciation, organic content and particle size were investigated. Elemental speciation and organic content of the soils did not appear to significantly affect the LA-ICP-MS measurements. Particle size, however, was found to influence the precision and sensitivity of the measurements. Samples with smaller particle sizes yielded higher signal levels and better precision.

Applications of LA-ICP-MS in the elemental analyses of geological samples

“…to <1 μm) [128]. If the particle size of the sample powder is relatively large or if the pellet is not sufficiently compacted, selective ablation of different minerals, signal variations caused by powder outbreak during ablation and the incomplete vaporization of particles could result in poor precision and accuracy [28,135]. The addition of binders could result in the production of discs with greater mechanical stability than that of discs obtained by pressing the sample alone, and the use of such discs could reduce signal instability caused by powder outbreak ablation [127,136].…”

“…If internal standard normalization is used, the element used as an internal standard should be analyzed using other independent methods (e.g. XRF or wet chemical methods) or added into the powder sample during the preparation of the pressed pellet or whole-rock glass [28,136]. The bulk content of volatile components (such as H 2 O and CO 2 ) in the sample should be accurately measured using other independent methods if the summed metal oxide normalization technique is used.…”

“…As a consequence, LA-ICP-MS has been used in the geosciences not only as a single-spot analysis method, especially where trace element or isotope concentrations are required at high spatial resolution (e.g. the analysis of a single fluid/melt inclusion, a single zircon grain, or the zonation of a mineral) [2,4,5,9-16] or distribution analyses of elements and isotopes of rocks and minerals are required [17][18][19][20][21], but also for bulk analyses of rocks and soils [22][23][24][25][26][27][28][29].…”

Laser ablation in analytical chemistry—a review

“…Several authors [135][136][137] have described the application of LA-ICP-MS for the analysis of whole-rock geological samples, such as pressed power pellets and lithium metaborate fusions.…”

Improved Analytical Characterization of Solid Waste-Forms by Fundamental Development of Laser Ablation Technology

“…For glasses, small size particles are condensed from vapor, whereas the recoil plasma interacting with the melted layer and an exfoliation process mainly produce larger particles and bulk solid flakes (31). For pressed pellets, particle generation processes also include shockwave spallation (52). F or high-density alloys, thermal vaporization may dominate the formation of small particles.…”