Preconcentration of manganese(II) from natural and sea water on a palmitoyl quinolin-8-ol functionalized XAD copolymer resin and spectrophotometric determination with the formaldoxime reagent Original Research Article

A palmitoyl quinolin-8-ol (P.Ox)-functionalized Amberlite XAD-2 copolymer resin (XAD-P.Ox) was used in the column mode to preconcentrate trace Mn(II) from artificial and real seawater, and Mn in the eluate was determined by the formaldoxime (FAD) spectrophotometric method, the results compared with those of FAAS. The optimal pH interval of Mn uptake by the resin was between pH 7 and 10 (best at 8). Other column operation parameters such as adsorption and elution flow rate, and eluent volume were optimized. Since a preconcentration factor of approximately 60 was achieved with the resin column, the detection limits (LOD) of spectrophotometry and FAAS for Mn (i.e. 17 and 12 μg l−1, respectively) were significantly reduced. The most serious interferent to the FAD procedure, i.e. ferric iron, was eliminated using the resin retention–elution procedure. The proposed method of preconcentration and analysis of Mn(II) was not adversely affected from high ionic strength media, rendering the method suitable for Mn determination in seawater.