Bulk optode sensors for batch and flow-through determinations of lead ion in water samples.

Shali Li, Leilei Du, Lu Zhang, Yue Hu, Wenchun Xia, Jia Wu, Jing Zhu, Lingling Chen, Fengqi Zhu, Chunxian Li, Sijun Yang

Index: Talanta 82(2) , 660-667, (2010)

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Abstract

A sensitive optode consisting of highly lead-selective ionophore (Lead IV), proton-selective chromoionophore (ETH 5294) and lipophilic anionic sites (KTpClPB) in plasticized polyvinyl chloride (PVC) membrane was fabricated. The optode membranes were used for determination of Pb(2+) by absorption spectrophotometry in batch and flow-through systems. The influence parameters such as pH, type of buffer solution, response time and concentration of regenerating solution were optimized. The membrane responded to Pb(2+) by changing its color from blue to pinkish purple in Tris buffer containing different concentration of Pb(2+) at pH 7.0. The optode provided the response range of 3.16x10(-8) to 5.00x10(-5) mol L(-1) Pb(2+) with the detection limit of 2.49x10(-8) mol L(-1) in the batch system within the response time of 30 min. The dynamic range of 1.26x10(-8) to 3.16x10(-5) mol L(-1) Pb(2+) with detection limit of 8.97x10(-9) mol L(-1) were obtained in the flow-through system within the response time of 15 min. Moreover, the proposed optode sensors showed good selectivity towards Pb(2+) over Na(+), K(+), Mg(2+), Cd(2+), Hg(2+) and Ag(+). It was successfully applied to determine Pb(2+) in real water samples and the results were compared with well-established inductively coupled plasma optical emission spectrometry (ICP-OES). No significant different value (t(critical)=4.30>t(exp)=1.00-3.42, n=3 at 95% of confidence level) was found.Copyright 2010 Elsevier B.V. All rights reserved.