Preconcentration/separation of lead at trace level from water samples by mixed micelle cloud point extraction

A mixed micelle-mediated cloud point extraction procedure was developed for lead. Triton-X114 and benzyldimethyl hexadecyl-ammonium chloride were used as mixed micellar medium. Lead(II) was reacted with 4-(2-pyridylazo) resorcinol at pH 6.0 to form hydrophobic chelates. The parameters including pH, ligand volume, concentrations of surfactants and centrifugation time were optimized. The effect of some common ions was also tested. The limit of detection was 1.15 mu g L-1 with preconcentration factor of 50. The accuracy of method was evaluated by the analysis of certified reference materials. The method was successfully applied to determination of levels of lead in water samples. (C) 2015 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.