[en] Preconcentration by 8-quinolinol (oxine) extraction to determine molybdenum concentration in natural water by ICP-AES is described. Selection of the organic solvent was investigated. The molybdenum-oxine complex was extracted quantitatively into nitrobenzene, which was directly introduced into the ICP. Interfering substances, such as iron and copper, were removed by shaking with 1 M HCl after the extraction. This method was applied to the determination of molybdenum in seawater. The effect of treating the samples with acids prior to extraction was studied. Organic forms of molybdenum and/or permolybdic acid may be present in natural waters. (author)