Development of an optode for detection of trace amounts of Hg2+ in different real samples based on immobilization of novel tetradentate Schiff bases bearing two thiol groups in PVC membrane.

Ayman A Abdel Aziz, Soha F Mohammed, Magdy M El Gamel

Index: J. Fluoresc. 24(3) , 859-74, (2014)

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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 Hg(2+) determination is described. At optimum conditions (i.e. pH 6.0), the proposed sensor displayed a linear response to Hg(2+) over 1.0 × 10(-10) - 1.0 × 10(-2) mol L(-1) with a limit of detection of 7.23 × 10(-11) mol L(-1) (0.0145 μgL(-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 Hg(2+) ion with respect to common metal cations. The sensor was successfully applied for determination of Hg(2+) 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.