Determination of Pb in river water samples by inductively coupled plasma optical emission spectrometry after ultrasound-assisted co-precipitation with manganese dioxide

A simple and efficient procedure for separation and pre-concentration using ultrasound-assisted co-precipitation with manganese dioxide was developed for Pb determination by inductively coupled plasma optical emission spectrometry (ICP OES). The optimization process was carried out using a two-level factorial design and a Doehlert matrix. Three variables (i.e. concentration of oxidizing solution-KMnO4, concentration of MnSO4 solution and time of ultrasonic irradiation) were used as factors in the optimization. The recoveries, based on the analysis of spiked samples, were between 90% and 105%, and the precision was <= 5%. The detection limit and quantification limit for Pb determination were 3.2 and 10.7 mu g L-1, respectively. The proposed method was applied for the determination of Pb in water samples from a river heavily polluted by industrial effluents. The recovery measured by analyte addition technique showed that the proposed preconcentration method had good accuracy. (c) 2005 Elsevier B.V. All rights reserved.