Application of multielectrode array modified with carbon nanotubes to simultaneous amperometric determination of dihydroxybenzene isomers

A novel multielectrode array modified with multiwall carbon nanotubes (MWCNTs) to simultaneous amperometric determination of dihydroxybenzene isomers was designed. The three oxidation peaks at the multielectrode array fabricated in 0.10 M KCl-0.20 M acetate buffer solution (pH 5.40) containing hydroquinone, catechol and resorcinol appeared at +0.192 V, +0.301 V and +0.683 V, corresponding to the oxidation of hydroquinone, catechol and resorcinol, respectively. A simple electrochemical method for simultaneous determination of dihydroxybenzene isomers was developed by multiple linear regression (MLR) method. Under the optimized conditions, the amperometric currents were linear over ranges from 1.0 × 10^-6 M to 1.0 × 10^-4 M for hydroquinone, from 1.0 × 10^-6 M to 1.0 × 10^-4 M for catechol and from 6.0 × 10^-6 M to 1.0 × 10^-4 M for resorcinol, with the detection limits of 3.0 × 10^-7 M, 2.0 × 10^-7 M and 6.0 × 10^-7 M, respectively. The developed method has been applied to simultaneous determination of dihydroxybenzene isomers in artificial wastewater with a satisfactory recovery from 97% to 101%. This work demonstrates that the MWCNTs-modified multielectrode array incorporating multiple linear regression method is a promising strategy for simultaneous electrochemical determination of isomers of organic compounds.