A method has been developed for the separation of Be, Co, Ni and Cr as their β-isopropyltropolone complexes on a reversed-phase column. Acetonitrile-water-methanol was used as a mobile phase. The geometric isomers of the trischelate of Cr(III) were also separated and the method was applied to the determination of chromium in air samples collected from an environment where welding work was being carried out.