The overall capacity of the microcolumn (C18, 5 μm beads, 20 mm × 1 mm × 0.1 mm) was calculated to be 0.45 μg/mm for Cr(VI). Loading only 80 μL samples onto the microchip and nebulizing the methanolic effluent of 30 μL into the FAA spectrometer, 0.0031 μg/mL limit of detection was obtained.