Synthesis and Characterization of 1-Chloro-4-Hydroxy-9H-Thioxanthen-9-One and its Efficient Application as Neutral Carrier for Preparation of New Copper Selective Electrode

Abstract

A new copper carbon paste electrode (CPE) based on 1-chloro-4-hydroxy-9H-thioxanthen-9-one has been prepared and investigated. The influence of variables including carbon paste composition, sodium tetraphenylborate (NaTPB), ionophore and Nujol on the electrode response was studied and optimized. The optimum conditions were set as following, carbon: NaTPB: Nujol: CHTX in the ratio of 77.11:0.37:22.05:0.46%. At optimum values of all variables, electrode response is linear over the 1.0 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX">$\,\times 10 ^{-6}$</tex></formula> to 1.0 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX">$\,\times 10 ^{-1}~{\rm mol ~L} ^{-1}$</tex></formula> with a Nernstian slope of 28.5 mV per decade of a <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX">${\rm Cu}^{2+}$</tex></formula> ion concentration. The good performance of electrode viz. low detection limit [3.16 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX">$\,\times 10 ^{-7}~{\rm mol~L} ^{-1}$</tex></formula> (20.2 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${\rm ng~m~ L} ^{-1}$</tex></formula> )], wide applicable pH range (2.8–5.8), fast response time (10 s) and adequate shelf life after (3 months) indicate the utility of the proposed electrode for evaluation of <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${\rm Cu}^{2+}$</tex></formula> ion content in various analysis. The good potentiometric selectivity coefficients evaluated by the fixed interference method (FIM) indicate selective response of proposed electrode for <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX">${\rm Cu}^{2+}$</tex></formula> ions over various interfering ions. Due to this good figure of merit, the proposed electrode could be successfully applied for the determination of <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${\rm Cu}^{2+}$</tex></formula> ions content in various real samples.