Determination of trace element partitioning between fluid and melt using LA-ICP-MS analysis of synthetic fluid inclusions in glass

The partitioning of trace elements between an aqueous chloride fluid phase and a granitic melt was investigated using laser ablation ICP-MS on synthetic fluid inclusions in glass. A granite melt was equilibrated with included vesicles containing the chloride solution at 850 degrees C and 2 kbar; rapid isobaric quenching preserves the host phase as an unfractured granitic glass which contains typically > 100 two-phase fluid inclusions. Glass matrix and fluid inclusions were analysed for Na, K, Al, Cl, Nb, Cs, Mo and W, the integrated fluid inclusion intensities being corrected for the contribution from the doped host glass by using integrated intensities for Si and Al. The reproducibility of inclusion analyses for Na, K, Cs, Mo and W ranges between 3 and 25 % relative. The analyses of inclusions and host glass permit calculation of partition coefficients for Na, K, Cs, Mo and W; results were compared with those using classical bulk analytical techniques.