A novel way of exploiting flow injection/sequential injection (FIA/SIA) on-line ion-exchange preconcentration with detection by electrothermal atomic absorption spectrometry (ETAAS) is described and demonstrated for the determination of trace-levels of nickel. Based on the use of a renewable microcolumn incorporated within an integrated micro FI-system, the column is loaded with a defined volume of small beads of an SP Sephadex C-25 cation-exchange resin and subsequently exposed to a metered amount of sample solution. However, instead of eluting the retained analyte from the organic ion-exchange resin, the beads are along with 30ml of carrier (buffer) solution transported via air segmentation directly into the graphite tube, where they are ashed during the pyrolysis and atomization process. The ETAAS determination is performed in parallel with the preconcentration process of the ensuing sample. An enrichment factor of 72.1, a detection limit of 9ng l−1, along with a sampling frequency of 12h−1 were obtained with 150 s of sample loading time at a sample flow rate of 12ml s−1 (corresponding to 0.72ml min−1). The relative standard deviations were 3.4%. The procedure was validated by determination of the nickel contents in two certified reference materials and in a human urine sample.