Yaftian MR, Rayati S, Emadi D, Matt D. A Coated Wire-type Lead(II) Ion-Selective Electrode Based on a Phosphorylated Calix[4]arene Derivative.
ANAL SCI 2006;
22:1075-8. [PMID:
16896245 DOI:
10.2116/analsci.22.1075]
[Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The preparation of a lead-selective electrode based on 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetrakis-(diphenylphosphinoylmethoxy)calix[4]arene (1) as an ionophore is reported. The plasticized PVC membrane containing 30% PVC, 57% ortho-nitrophenyloctylether (NPOE), 4% sodium tetraphenylborate (NaTPB) and 9% ionophore 1 was directly coated on a graphite electrode. It exhibits a nearly Nernstian slope of 28.0 +/- 0.2 mV decade(-1) over a concentration range of 1 x 10(-5) - 1 x 10(-2) mol dm(-3) with a detection limit of 1.4 x 10(-6) mol dm(-3). The response time of the electrode was found to be ca. 17 s. The potential of the sensor was independent of the pH variation in the range 3.5 - 5.0. The selectivity of the electrode performance towards lead ions over Th4+, La3+, Sm3+, Dy3+, Y3+, Ca2+, Sr2+, Cd2+, Mn2+, Zn2+, Ni2+, Co2+, NH4+ Ag+, Li+, Na+ and K+ ions was investigated. The prepared electrode was used successfully as an indicator electrode for a potentiometric titration of a lead solution using a standard solution of EDTA. The applicability of the sensor for Pb2+ measurements in various synthetic water samples spiked with lead nitrate was also checked.
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