Investigation on simultaneous determination of dihydroxybenzene isomers in water samples using multi-walled carbon nanotube modified screen-printed electrode

A disposable electrode, multi-walled carbon nanotube modified screen printed electrode (MWCNT/SPE), had been fabricated using screen printing technology and drop-coating method to determine dihydroxybenzene isomers (hydroquinone, catechol and resorcinol). The cyclic voltammetry behavior of dihydroxybenzene isomers had been investigated with the MWCNT/SPE. The results reveal that MWCNT/SPE, which shows a strong electrocatalytic activity for the oxidation of dihydroxybenzenes, can entirely separate the oxidation peaks of them. According to differential pulse voltammetry tests, the peak currents of dihydroxybenzene isomers are linear to their concentrations at the range of 8.20 × 10^-6-1.00 ×10^-3, 8.20 × 10^-6-1.00 × 10^-3 and 1.64 × 10^-5-1.16 × 10^-3 mol · L^-1, with the detection limits of 4.34 × 10^-6, 3.42 × 10^-6 and 6.70 × 10^-6 mol · L^-1 for hydroquinone, catechol and resorcinol, respectively. For the determination of dihydroxybenzene isomers in water samples, the value of recovery found by standard addition method was in the range of 96.2%-104.9%. These results indicate MWCNT/SPE can be applied to rapid in-situ determination of dihydroxybenzenes-polluted water samples.