A method of separation and preconcentration for the determination of Zn, Cu, and Mn in natural water was described and real samples studied using flame atomic absorption spectrometry. The method is based on the adsorption of Mn 2+ , Cu 2+ and Zn 2+ onto 3-((1H-Indol-3-yl)(3-nitrophenol)methyl)-1H indole (INMI) that is loaded onto Triton X-100-coated polyvinyl chloride. The effects of pH, reagent amount, sample volume and matrix of the sample on the sorption of metal ions were also investigated. Detection limits (3 SDb/m) of 1.9, 2.1 and 1.8 ng mL −1 for Cu 2+ , Zn 2+ and Mn 2+ along with a preconcentration factor of 270 for these ions were achieved. We demonstrated highly efficient solid phase extraction for the determination of analytes in complex matrices. The proposed procedure was applied to analyses of industrial, natural and waste water as well as to those of soil and fruit samples.