Simultaneous Determination of Hydroquinone, Catechol and Resorcinol at Graphene Doped Carbon Ionic Liquid Electrode

Abstract

A new composite electrode has been prepared with doping graphene into the paste consisting graphite and ionic liquid, n-octyl-pyridinum hexafluorophosphate (OPFP). This electrode shows an excellent electrochemical activity for the redox of hydroquinone (HQ), catechol (CC), and resorcinol (RS). In comparison with bare paste electrode, the redox peaks of three isomers of dihydroxybenzene can be obviously, simultaneously observed at graphene doping paste electrode. Under the optimized condition, the simultaneous determination of HQ, CC, and RS in their ternary mixture can be carried out with a differential pulse voltammetric technique. 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The limits of detection are <svg style="vertical-align:-0.3135pt;width:65.824997px;" id="M7" height="14.4625" version="1.1" viewBox="0 0 65.824997 14.4625" width="65.824997" xmlns="http://www.w3.org/2000/svg"> <g transform="matrix(1.25,0,0,-1.25,0,14.4625)"> <g transform="translate(72,-60.43)"> <text transform="matrix(1,0,0,-1,-71.95,60.79)"> <tspan style="font-size: 12.50px; " x="0" y="0">1</tspan> <tspan style="font-size: 12.50px; " x="6.2515001" y="0">.</tspan> <tspan style="font-size: 12.50px; " x="9.3772497" y="0">8</tspan> <tspan style="font-size: 12.50px; " x="18.404415" y="0">×</tspan> <tspan style="font-size: 12.50px; " x="29.182001" y="0">1</tspan> <tspan style="font-size: 12.50px; " x="35.433502" y="0">0</tspan> </text> <text transform="matrix(1,0,0,-1,-30.26,65.96)"> <tspan style="font-size: 8.75px; " x="0" y="0">−</tspan> <tspan style="font-size: 8.75px; " x="5.99512" y="0">6</tspan> </text> </g> </g> </svg>&#x2009;mol&#x2009;L<sup >&#x2212;1</sup> for HQ, <svg style="vertical-align:-0.3135pt;width:65.824997px;" id="M8" height="14.225" version="1.1" viewBox="0 0 65.824997 14.225" width="65.824997" xmlns="http://www.w3.org/2000/svg"> <g transform="matrix(1.25,0,0,-1.25,0,14.225)"> <g transform="translate(72,-60.62)"> <text transform="matrix(1,0,0,-1,-71.95,60.99)"> <tspan style="font-size: 12.50px; " x="0" y="0">7</tspan> <tspan style="font-size: 12.50px; " x="6.2515001" y="0">.</tspan> <tspan style="font-size: 12.50px; " x="9.3772497" y="0">4</tspan> <tspan style="font-size: 12.50px; " x="18.404415" y="0">×</tspan> <tspan style="font-size: 12.50px; " x="29.182001" y="0">1</tspan> <tspan style="font-size: 12.50px; " x="35.433502" y="0">0</tspan> </text> <text transform="matrix(1,0,0,-1,-30.26,66.16)"> <tspan style="font-size: 8.75px; " x="0" y="0">−</tspan> <tspan style="font-size: 8.75px; " x="5.99512" y="0">7</tspan> </text> </g> </g> </svg>&#x2009;mol&#x2009;L<sup >&#x2212;1</sup> for CC, and <svg style="vertical-align:-0.3135pt;width:65.824997px;" id="M9" height="14.225" version="1.1" viewBox="0 0 65.824997 14.225" width="65.824997" xmlns="http://www.w3.org/2000/svg"> <g transform="matrix(1.25,0,0,-1.25,0,14.225)"> <g transform="translate(72,-60.62)"> <text transform="matrix(1,0,0,-1,-71.95,60.99)"> <tspan style="font-size: 12.50px; " x="0" y="0">3</tspan> <tspan style="font-size: 12.50px; " x="6.2515001" y="0">.</tspan> <tspan style="font-size: 12.50px; " x="9.3772497" y="0">6</tspan> <tspan style="font-size: 12.50px; " x="18.404415" y="0">×</tspan> <tspan style="font-size: 12.50px; " x="29.182001" y="0">1</tspan> <tspan style="font-size: 12.50px; " x="35.433502" y="0">0</tspan> </text> <text transform="matrix(1,0,0,-1,-30.26,66.16)"> <tspan style="font-size: 8.75px; " x="0" y="0">−</tspan> <tspan style="font-size: 8.75px; " x="5.99512" y="0">7</tspan> </text> </g> </g> </svg>&#x2009;M for RS, respectively.