Solid‐phase extraction and pre‐concentration of trace metals in natural waters using indigenously synthesized chelating resin and their subsequent determination by ICP‐OES

A laboratory made chelating resin based on immobilization of fluorinated beta-diketone group on styrene divinyl benzene was employed for the extraction and pre-concentration of trace metals in natural water samples before their determination by inductively coupled plasma optical emission spectrometry (ICP-OES). Extraction efficiency of the resin toward metal ions was examined by column procedure. Various experimental parameters consisting pH, sample loading flow rate, eluent concentration/volume and breakthrough limits were investigated for the effective uptake of metals on the resin. The resin capacity at pH (9) was found to be 10.20, 9.13, 7.47, 8.67, 3.12, 6.45 and 9.80 mg g-1 for Cd (Cadmium), Co (Cobalt), Fe (Iron), Mn (Manganese), Mo (Molybdenum), Ni (Nickel) and Zn (Zinc), respectively. The method was applied for the extraction/pre-concentration of Cd, Co, Fe, Mn, Mo, Ni and Zn in natural water samples and their subsequent determination was carried out by ICP-OES. Percentage recoveries obtained for the selected metals except Mo were = 95% under similar experimental conditions with < 5% relative standard deviation. Alkali/alkaline earth metals, the major matrix ions were not retained on the resin, the resin is selective for trace metals, therefore it is suitable for the extraction of these metals in natural water samples for environmental and health-related studies. (C) 2011 Curtin University of Technology and John Wiley & Sons, Ltd.