Simultaneous determination of hydroquinone and catechol by SWNTs/GC electrode

A single-walled carbon nanotubes modified glassy carbon(SWNTs/GC) electrode was prepared.The electrochemical determination of two dihydroxybenzenes(hydroquinone and catechol) at the SWNTs/GC electrode was investigated by cyclic voltammetry.The results showed that the SWNTs/GC electrode exhibited strong recognition and electrocatalytical ability toward two isomers.The oxidation peak potential difference between hydroquinone and catechol was 106 mV,which indicated that the two isomers could be identified entirely at the SWNTs/GC electrode.Based on their voltammetric behavior,a method was proposed for the simultaneous determination of two dihydroxybenzenes at the SWNTs/GC electrode.Under the optimum conditions,the calibration curves showed good linear relationship for catechol with the range of 3.0×10-6~8.0×10-5 mol·L-1,and its detection limit was 1.0×10-6 mol·L-1.The oxidation peak current was linearly proportional to the concentration of hydroquinone with the range of 8.0×10-6~1.0×10-4 mol·L-1,and its detection limit was 2.67×10-6 mol·L-1.