Spectrophotometric detremination of Lead in Environment Samples by Benzoic acid Azo PhenylCalix[4]arene (BAPC)

Abstract

A new and selective spectrophotometric method for the determination of trace amounts of Pb(II) in aqueous environmental samples is reported. The interaction in solution between Pb(II) and Benzoic acid Azo Phenyl Calix[4]arene (BAPC, 1) was studied. Upon reaction of PABC and Pb(II) a stable complex is formed. Under the conditions reported here the method furnishes reproducible results with basic media. The calixarene derivative shows strong binding ability to Pb 2+ ion with formation of a 1:1 complex. Beer's law is obeyed in the range of 2.0×10-6 − 2.4×10-5 molL-1 of Pb 2+. The apparent molar absorptivity (ε) of 1-Pb 2+ complex was 1.89 x10 4 Lmol-1 cm-1 at 440 nm, and the detection limit is 1.4x10-6 mol L-1. The calixarene 1 showed high sensitivity and selectivity for Pb 2+. The method was used to determine the content of Pb(II) in synthetic and natural samples.