Laser ablation-ICPMS

Direct sampling of solids may be carried out using laser ablation. In this technique a high-power laser, usually a pulsed Nd-YAG laser, is used to vaporize the solid, which is then swept into the plasma for ionization. Besides not requiring dissolution or other chemistry to be performed on the sample, laser ablation ICPMS (LA-ICPMS) allows spatial resolution of 20-50 pm. Depth resolution is 1-10 pm per pulse. This aspect gives LA-ICPMS unique dit nostic capabilities for geologic samples, surface features, and other inhomogeneous samples. In addition minimal, or no, sample preparation is required. 

Norman, M. D., Pearson, N. J., Sharma, A., and Griffin, W. L. (1996). Quantitative analysis of trace elements in geological materials by laser ablation ICPMS instrumental operating conditions and calibration values of NIST glasses. Geostandards Newsletter 20 247-261. 

Prohaska, T., Stadlbauer, C., Wimmer, R., et al. (1998). Investigation of element variability in tree rings of young Norway spruce by laser-ablation-ICPMS. Science of the Total Environment 219 29-39. 

Sylvester, P. (ed.) (2001). Laser-Ablation-ICPMS in the Earth Sciences principles and applications. Ottawa, Ont, Mineralogical Association of Canada. 

Keywords NI-Cu-PGE deposit, sulfides, Sudbury, Laser-Ablation ICPMS, PGM... 

However, for many of the PGE, the concentrations in ores from Ni-Cu-PGE deposits were less than detection limit, laser ablation ICPMS (LA-ICPMS) offers three advantages over these techniques, namely 1) lower detection limits (ppb level), 2) accessibility, and 3) time-resolved analysis. 

Rare earth element variations in volcanogenic massive sulfides, Bathurst Mining Camp, New Brunswick evidence from laser-ablation ICPMS analyses of phosphate accessory phases... 

B. Hattendorf, C. Latkoczy, and D. Gunther, Laser Ablation-ICPMS, ... 

Gtlnther, D. Hattendorf, B. In Laser-Ablation-ICPMS an the Earth Sciences Principles and Applications, Sylvester, P., Ed. Short Course Series Mineralogical Assocation of Canada St. Johns, Newfoundland, 2001 Vol.29, pp 83-91. 

T. W. M. Fan, E. Pruszkowski, S. Shuttleworth, Speciation of selenoproteins in Se-contaminated wildlife by gel electrophoresis and laser ablation-ICPMS, J. Anal. Atom. Spectrom., 17 (2002), 1621-1623. 

Figure 24 Concentration profiles of siderophile elements in a radially zoned Fe,Ni grain in the CBb chondrite, QUE 94411 (a) electron microprobe data (b) and (c) trace element data from laser ablation ICPMS (Campbell et ai, 2001). The nickel, cobalt, and chromium profiles can be matched by nonequilibrium nebular condensation assuming an enhanced dust-gas ratio of —36 X solar, partial condensation of chromium into silicates, and isolation of 4% of condensates per degree of cooling (Petaev etal, 2001). Concentrations of the refractory siderophile elements, osmium, iridium, platinum, ruthenium, and rhodium, are enriched at the center of the grain by factors of 2.5-3 relative to edge concentrations, which are near Cl levels after normalization to iron (reproduced by permission of University of Arizona on behalf of The Meteoritical Society from Meteorit. Planet. ScL, 2002, 37, pp. 1451-1490).

Norman M. (2001) Apphcations of laser-ablation ICPMS to the trace element geochemistry of basaltic magmas and mantle evolution. In Min. Assoc. Can. Short Course Series (ed. P. Sylvester). Ottawa, vol. 29, pp. 163-184. 

Norman M. D. (1998) Melting and metasomatism in the continental hthosphere laser ablation ICPMS analysis of minerals in spinel Iherzohtes from eastern Australia. Contrib. Mineral. Petrol. 130, 240-255. 

Kosler J., Fonneland H., Sylvester P., Tubrett M., and Pedersen R. B. (2002) U—Pb dating of detrital zircons for sediment provenance studies a comparison of laser ablation ICPMS and SIMS techniques. Chem. Geol. 182(2—4), 605-618. 

Milton D. A. and Cheney S. R. (1998) The effect of otolith storage methods on the concentration of elements detected by laser-ablation ICPMS. J. Fish Biol. 53, 785-794. 

Fig. 4. Element to calcium ratios in Globigerinoides sacculifer and G. ruber determined by laser ablation ICPMS indicating the spatial heterogeneity in Mg concentrations in G. sacculifer but not in G. ruber (modified after Eggins et al. 2003). The Mg concentrations are higher in the inner part of G. sacculifer but constant in G. ruber which lacks Mg-poor gametogenic calcite. In contrast, Sr concentrations are relatively stable throughout the test and very similar for both species. Note that the 1 pm layer with very high Mg values, which we interpret as contamination on the outside of the test, has been excluded from this plot to highlight the internal variability. The different duration of the analysis is determined by the thickness of the foraminiferal test.

Lyakhovich W (1961) Accessory minerals and the absolute age of igneous rocks. Trudy Inst Mineral Geokhim Krisallokhim Redkikh Elementov 7 212-225 Machado N, Gauthier G (1996) Determination of Pb/ Pb ages on zircon and monazite by laser-ablation ICPMS and apphcation to a study of sedimentary provenance and metamorphism in southeastern Brazil. Geochim Cosmochim Acta 60 5063-5073... 

Eggins, S., Grtin, R., Pike, A.W.G., Shelley, M.,Taylor, L. (2003) U, h profiling and U-series isotope analysis of fossil teeth by laser ablation-ICPMS. Quaternary Science Reviews, 22(10-13), 1373-1382. 

Hattendorf, B., Latkoczy, C, Gunther, D. (2003) Laser ablation-ICPMS. Analytical Chemistry, 75,341A-347A. 

Hoffmann, D.L., Paterson, B.A., Jonckheere, R. (2008) Measurements of the uranium concentration and distribution in a fossil equid tooth using fission tracks, TIMS and laser ablation ICPMS implications for ESR dating. Radiation Measurements, 43, 5-13. 

FIGURE 1.30 A schematic representation of the laser ablation—ICPMS system. (From Gunther, D. and Hattendorf, B., TrAC, 255, 2005. With permission.)... 

The uranium content in soil can be determined directly by some analytical methods that are mainly based on nuclear techniques (variations of neutron activation analysis, gamma spectrometry, x-ray fluorescence, or laser-ablation ICPMS), but the common, popular, and more accurate methods require digestion and dissolution of the entire soil sample or at least rely on leaching the uranium out of the sample matrix. In principle, the methods used for assaying uranium in minerals (see Chapter 2) are also suitable for soil characterization, but uranium is usually present in the latter only as a low-level impurity, usually below 100 pg U g. We shall first overview the procedures deployed for the treatment of soil samples prior to analysis and refer to the analytical devices used for the measuranent of the uranium content and isotopic composition in these studies. 

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