MICROPROBE ANALYSIS OF GEOLOGICAL-MATERIALS BY LASER ABLATION INDUCTIVELY COUPLED PLASMA MASS-SPECTROMETRY

The distribution of 25 elements from Mg to U in the geological materials, stalactite and fossil shell were obtained by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The laser pulses in the free-running mode were fired several times at the same position while the samples were fixed in each measurement. The variation of the signal intensity was normalized using the Ca-43 signal as the internal standard, assuming that the CaCO3 content is 100% in every position. The standards were made from part of the samples themselves, whose elemental concentrations were determined separately by solution method. The analytical results by laser method for the inhomogeneous geological samples were assessed with those obtained by solution analysis.