Abstract
A very sensitive and reversible optical chemical sensor based on a novel tetradentate Schiff base namely N.N(/)bis(2-aminothiophenol)benzene-1,2-dicarboxaldehyde (ATBD) immobilized within a plasticized PVC film for Hg2+ determination is described. At optimum conditions (i.e. pH 6.0), the proposed sensor displayed a linear response to Hg2+ over 1.0 x 10(-10) - 1.0 x 10(-2) mol L-1 with a limit of detection of 7.23 x 10(-11) mol L-1 (0.0145 mu gL(-1)). Moreover, the results revealed that, under batch condition, the sensor is fully reversible within a response time 35 s. In addition to its high stability and reproducibility, the sensor showed good selectivity towards Hg2+ ion with respect to common metal cations. The sensor was successfully applied for determination of Hg2+ ion in some real samples, including hair, urine and well water samples. The results were in good correlation with the data obtained using cold vapor atomic absorption spectrometry.