Abstract: Five natural sulfide minerals were determined using laser ablation inductively coupled plasma mass spectrometry(LA-ICP-MS) with a 193 nm ArF excimer laser ablation system. Elemental fractionation effect and influences of spot size, repetition rate and laser energy on laser ablation behavior of different sulfides were investigated based on different laser ablation profiles and transient signal response. The results show that laser ablation characteristics and elemental fractionation effect of sulfides vary significantly with the physical properties and chemical components of sulfides. The ablation halos of pyrite, molybdenite and sphalerite are approximately 10 times the diameter of the corresponding spot size, whereas chalcopyrite and pyrrhotite are about 14 times. The elemental fractionation indexes(EFI) indicate that pyrite and molybdenite behave apparent elemental fractionation while chalcopyrite, pyrrhotite and sphalerite, EFI of which approached to 1.0, do not. For sulfide minerals microanalysis by LA-ICP-MS, accurate analysis results can be obtained under the laser ablation parameters of large spot size, low repetition rate and low laser energy.

Key words: Sulfide mineral, Laser ablation inductively coupled plasma mass spectrometry(LA-ICP-MS), Elemental signal response