A method for on-line preconcentration of palladium at ultra-trace level on alumina microcolumns and determination by inductively coupled plasma mass spectrometry (ICP-MS) has been developed. A sampling time of 10 min (30 ml) and an eluent (KCN) volume of 300 μl provides a limit of detection of 1 ng l −1. The precision was 4% at the 25 ng l −1 level. The proposed system allows the on-line removal of the primary 105 Pd interferents (Cu and Y) providing the credible accuracy of the results. The proposed method is suitable for palladium determination in urban water samples. Platinum concentration in the analysed urban water samples was also determined.