QUANTITATIVE-ANALYSIS OF TRACE-ELEMENTS IN GEOLOGICAL-MATERIALS BY LASER-ABLATION ICPMS - INSTRUMENTAL OPERATING-CONDITIONS AND CALIBRATIONVALUES OF NIST GLASSES
Md. Norman et al., QUANTITATIVE-ANALYSIS OF TRACE-ELEMENTS IN GEOLOGICAL-MATERIALS BY LASER-ABLATION ICPMS - INSTRUMENTAL OPERATING-CONDITIONS AND CALIBRATIONVALUES OF NIST GLASSES, Geostandards newsletter, 20(2), 1996, pp. 247-261
A UV laser ablation microprobe coupled to an ICPMS has been used to de
termine trace element concentrations in solids with a spatial resoluti
on of less than or equal to 50 microns and detection limits ranging fr
om less than or equal to 2 mu g/g for Ni to less than or equal to 50 n
g/g for the REE, Th, and U. Experiments designed to optimize laser ope
rating conditions show that pulse rates of 4 Hz produce a steady state
signal with less inter-element fractionation per unit time than highe
r pulse rates (10-20 Hz). Comparisons of laser microprobe analyses of
garnets and pyroxenes using the NIST 610 and 612 glasses as calibratio
n standards, with proton microprobe, solution ICPMS, INAA and XRF data
show no significant matrix effects. Laser microprobe analyses of the
NIST 610 and 612 glasses have a precision and accuracy of 2-5%, and er
ror analysis shows that counting statistics and the precision on the i
nternal standard concentration accounts for the analytical uncertainty
. The NIST glasses appear to be useful calibration materials for trace
element analysis of geological materials by laser microprobe.