Amperometric Detection Of Hydroquinone At Modified Ionic Liquid Graphene Composite Paste Electrode

The ionic liquid 1-ethyl-3-methylimidazolium bromide (EMIMBr) based graphene composite paste electrode (GrPE) was fabricated and applied for the determination of hydroquinone. By using square wave voltammetry, the electrochemical response of hydroquinone on EMIMBr-GrPE was greatly enhanced in 0.7 M phosphate buffer solution (pH 7.0). Under optimized conditions, the proposed electrode showed a linear relationship with concentration in the range of 1.0x10(-6) to 1.0x10(-2) M hydroquinone with limit of detection of 2.77x10(-7) M. The interferences of Ba2+, Cu2+, Na+, K+, NO3-, Cl-, SO42-, glycine, glucose, fructose and sucrose were negligible. Electrochemical impedance spectroscopy indicated that the charge transfer at the electrode-solution interface was excellent. The proposed electrode was successfully applied to determine of hydroquinone in wastewater and cosmetic creams with range of recovery 97 - 104%.