A method for mercury speciation analysis was developed by CE-ICP-MS with a Micro Mist nebulizer and a removable interface. Contamination of ICP-MS detector by the rising solution was avoided with the use of a removable interface during capillary rinsing. Baseline separation of methylmercury (MeHg) and inorganic mercury (Hg2+) was obtained by CE in a 45 cm x 75 microm i.d. fused-silica capillary at 22.5 kV, while a mixture of 30 mmol(-1) H3BO3 + 10% CH3OH (pH 8.7) acted as running electrolyte. The precisions (RSD, n=5) of migration time and peak area for the mercury species were in the ranges of 3.5%-3.8% and 2.3%-5.1%, respectively. The limits of detection (3sigma) of MeHg and Hg2+ were 47 and 48 microg x L(-1), respectively.