Multiple trace element analyses for silicate minerals and glasses by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS)

Abstract

( 2015 ) Multiple trace element analyses for silicate minerals and glasses by laser ablation-inductively coupled plasma-mass spectrometry ( LA-ICP-MS ) . Bull. Geol. Surv. Japan, vol. 66 ( 9/10 ) , 6 figures, 6 tables.Abstract: Programs were established in the shared research facilities of the Geological Survey of Japan ( GSJ-Lab ) for trace element analysis of silicate minerals and glasses in microspots using laser ablationinductively coupled plasma-mass spectrometry ( LA-ICP-MS ) . National Institute of Standards and Technology ( NIST ) synthetic glasses reference materials ( NIST 613 and NIST 611 ) were used as external calibration standards, and suitable instrumental operation settings were set as follows; 0.5 L min -1 He carrier gas flow rate, 100 μm laser spot diameter, 5 Hz repetition rate, and 40 % laser energy ( fluence ca. 2.0 J cm -2 ) . NIST 615 and NIST 613 were analyzed as unknown samples to evaluate precision and accuracy. Precision was mostly less than 30 % for 45 elements from 45 Sc to 238 U for laser spot diameters ranging from 100 to 10 μm. Accuracy was evaluated according to the difference ( DIF ) between the analytical results and reference values in the literature. Accuracy for the analysis of NIST 613 was DIF < 30 %, except for Sc, Mn, Ni, and Ge. For NIST 615, DIF was less than 30 %, except for Tl with laser spot diameters of 20 and 10 μm, and for Cd with a laser spot diameter of 20 μm. The depths of laser pits for generic conditions for the analysis of clinopyroxene, amphiboles and plagioclase were estimated as extents without penetration of the thin section samples. Two suites of analytical programs ( 34 and 27 elements ) were additionally prepared for general purpose petrological and geochemical discussion and the accuracy of both was evaluated. The DIFs for the suite of 34 elements were mostly less than 30 %, although some for Cr, Mn, Ni, and Cs with laser spot diameters < 40 μm exceeded 30 %. In the suite of 27 elements, the DIFs were < 30 %, except for Sc.

Whole rock multiple trace element analyses using fused glass bead by laser ablation-ICP-MS

“…Detailed information about the instrument is given in Yamasaki et al (2015). The large sample chamber allowed nine glass beads, including the calibration reference material, to be loaded and analyzed in a single uninterrupted session.…”

“…following the results of Yamasaki et al (2015). Prior to analysis, the LA-ICP-MS system was calibrated using NIST613 reference glass for high sensitivity over a large mass range and low production rate of oxides.…”

“…The same analytical elements were used as those in the full elemental set of Yamasaki et al (2015), and 100 sweeps of 45 elements from 45 Sc to 238 U with dwell times shown in Table 2 were replicated three times in the peak hopping and spectrum modes. The acquisition time on ICP-MS was ca.…”

“…85 s, including 10 s for both the shuttered laser warm-up and laser stabilization. After completing the ablation, signal intensities returned to background levels after approximately 25 s (Yamasaki et al, 2015). All signal intensities were corrected with respect to the background signal obtained from the measurement of a gas blank for 40 s prior to initiating the calibration standard and unknown measurements.…”

“…Advantages and disadvantages of the solution and − 28 − Japan, vol. 67 (1), 2016 LA methods have been described by Yamasaki et al (2015).…”