EarthRef.org Reference Database (ERR) -- Dalpe et al. 1995

The synchrotron X-ray-fluorescence microprobe (SXRFM) and laser-ablation microprobe with inductively coupled plasma - mass spectrometer (LAM-ICP-MS) have been found to be efficient instruments for the accurate measurement of a large suite of trace elements in natural and synthetic minerals and glasses. The small beam-sizes of both instruments (10 and 34 mu m in diameter for SXRFM and LAM-ICP-MS, respectively) permit in situ analysis of samples whose cross-section is at least 7500 mu m(2) (i.e., corresponding to a sampling area of 50 x 150 mu m analyzed by LAM-ICP-MS in rastered grid). This sampling technique applied to LAM-ICP-MS avoids sample damage and minimizes the depth of penetration by the laser using a single hole. Optimization of both instruments was carried out using two in-house basaltic glass standards. The lower limits of detection of the SXRFM for Rb, Sr, Y, Zr, and Nb are approximately 5.5 ppm or less, based upon our in-house standards, and the analyses have an associated precision of +/- 20% relative. The lower limits of detection of the LAM-ICP-MS are approximately 2 ppm or less; these analyses have a precision of +/- 10 to 15% relative. Both instruments were used to measure partition coefficients between a Ti-rich calcic amphibole and a Ti-rich basanitic quenched glass produced experimentally. The D values determined by SXRFM for Sr, Y, and Zr are: D-Sr, 0.32 (+/- 0.04), D-Y 0.25 (+/- 0.04), D-Zr 0.12 (+/- 0.07). Partition coefficients determined by LAM-ICP-MS are: D-Rb 0.22 (+/- 0.04), D-Sr 0.38 (+/- 0.01), D-Y 0.33 (+/- 0.03), D-Zr, 0.12 (+/- 0.01), D-Nb 0.05 (+/- 0.01). The LAM-ICP-MS was also used to measure the D values for Ba, Ta, La, Ce, Nd, Hf, Sm, and Eu, which are: D-Ba 0.28 (+/- 0.01), D-Ta 0.07 (+/- 0.02), D-La 0.039 (+/- 0.005), D-Ce 0.067 (+/- 0.002), D-Nd 0.14 (+/- 0.01), D-Hf 0.33 (+/- 0.01), D-Sm 0.19 (+/- 0.08), and D-Eu 0.35 (+/- 0.02).