A glass rod (5-20 cm long, 2 mm o.d.) containing more than 1200 parallel microchannels (<40 μm i.d.) was converted into a high-resolution (> 100 theoretical plates cm-1) GC column by coating the inside of each channel in a way that compensated for the dispersion of the channel inner diameter. The columns were evaluated for the separation of mixtures of several organometallic (Hg, Sn, Pb) compounds prior to on-line sensitive metal- selective detection by ICPMS. Chromatographic separation conditions were optimized to enable a rapid (within a maximum 30 s) multielemental speciation analysis. Absolute detection limits were 0.1 pg for Hg, 0.05 pg for Sn, and 0.03 pg for Pb using the carrier gas flows of ~200 mL min-1. The microcolumn multicapillary GC/ICPMS developed was applied to the analysis of a number of environmental samples. The results were validated with certified reference materials for fin (BCR477, PACS-2) and mercury (DORM-1, TORT-1).