Microwave-assisted synthesis of a new chelating resin containing 2-aminothiophenyl S-acetic acid and its application to the determination of lead

Chloromethyl polystyrene has been functionalised with 2-aminothiophenyl S-acetic acid using microwave assisted reflux. The resulting chelating resin has been characterised by elemental analyses, infrared spectra, thermogravimetric analysis, hydrogen ion capacity and metal sorption capacity. It has been used for the preconcentration and separation of lead prior to its determination by flame atomic absorption spectrometry. The optimum conditions for both synthesis of the resin as well as the digestion of the road dust samples by microwave assisted treatment have been evaluated. Parameters such as the amount of the resin, effect of pH, equilibration rate, sorption and desorption of metal ions, and effect of diverse ions have been studied. The maximum sorption capacity for lead was found to be 0.03 mmol g(-1) at the pH range 5.5-6.0. Recovery of Pb(II) was 98.9+/-3.5 at the 99% confidence level with a detection limit of 40.6 ng ml(-1). The proposed method has also been applied for the determination of lead in road dust. (C) 2002 Elsevier Science B.V. All rights reserved.