DETERMINATION OF PARTITION-COEFFICIENTS FOR TRACE-ELEMENTS IN HIGH-PRESSURE TEMPERATURE EXPERIMENTAL RUN PRODUCTS BY LASER-ABLATION MICROPROBE INDUCTIVELY-COUPLED PLASMA-MASS SPECTROMETRY (LAM-ICP-MS)

This paper reports the first trace element partition coefficients meas ured on experimentally produced products (clinopyroxene, garnet, rutil e, and glass) by laser ablation microprobe-inductively coupled plasma- mass spectrometry (LAM-ICP-MS). A 266 nm (UV) laser microprobe was use d to improve ablation characteristics and to achieve a fourfold reduct ion in ablation pit diameter compared to the previously used 1064 nm b eam. Results are compared with PIXE analyses on the same experimental products, and literature values, where available, for similar systems, and include the first simultaneously measured partition coefficients for Zr, Nb, and Ta between rutile and glass. Advantages of the LAM tec hnique include rapid results and simultaneous determination of a wide range of major and trace elements, thus ensuring sampling integrity th rough time-resolved analysis of the sampled material.