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Lead‐Selective Electrode Based on a Quinaldic Acid Derivative
Author(s) -
Casado Marta,
Daunert Sylvia,
Valiente Manuel
Publication year - 2001
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/1521-4109(200101)13:1<54::aid-elan54>3.0.co;2-1
Subject(s) - ionophore , chemistry , inorganic chemistry , polyvinyl chloride , carboxylic acid , ion selective electrode , electrode , vinyl chloride , metal ions in aqueous solution , membrane , plasticizer , chloride , quinoline , derivative (finance) , metal , detection limit , nuclear chemistry , polymer chemistry , selectivity , organic chemistry , chromatography , biochemistry , polymer , economics , financial economics , copolymer , catalysis
The derivative of quinaldic acid, 8‐(dodecyloxy)quinoline‐2‐carboxylic acid, has been used as an ionophore in the development of a lead(II)‐selective electrode. Solvent extraction studies showed that this compound is selective for lead(II) and copper(II) over a variety of divalent and monovalent metals. Liquid polymeric membranes of plasticized poly(vinyl chloride) were prepared using bis‐(2‐ethylhexyl) sebacate as the plasticizer and the lead(II) complex of 8‐dodecyloxy quinoline‐2‐carboxylic acid as the ionophore. The effect of several parameters, such as content of ionophore in the membrane, pH of the sample solution, and electrode conditioning was investigated. When optimized, the electrode responded in a near‐Nernstian fashion to lead(II) and the detection limit was found to be 5.0×10 −7 M. The electrode is selective for Pb 2+ over Cu 2+ , Al 3+ , Mn 2+ , Ni 2+ , Co 2+ , Zn 2+ , Mg 2+ , Ca 2+ , Na + , K + , with Hg 2+ and Cu 2+ the most interfering metal ions.