Covalent modification of glassy carbon electrode with aspartic acid for simultaneous determination of hydroquinone and catechol.
Glassy carbon electrode (GCE) is covalently modified with aspartic acid (Asp). The modified electrode is used for the simultaneous electrochemical determination of hydroquinone (HQ) and catechol (CC) and shows an excellent electrocatalytical effect on the oxidation of HQ and CC by cyclic voltammetry (CV) in 0.1 mol/L acetate buffer solution (pH 4.5). In differential pulse voltammetric (DPV) measurements, the modified electrode could separate the oxidation peak potentials of HQ and CC present in binary mixtures by about 101 mV though the bare electrode gave a single broad response. A successful elimination of the fouling effect by the oxidized product of HQ on the response of CC has been achieved at the modified electrode. The determination limit of HQ in the presence of 0.1 mmol/L CC was 9.0 x 10(-7) mol/L and the determination limit of CC in the presence of 0.1 mmol/L HQ was 5.0 x 10(-7) mol/L. The proposed method has been applied to the simultaneous determination of HQ and CC in a water sample with simplicity and high selectivity.
Wang
Liang
L
College of Life Science, Dalian Nationalities University, Dalian 116600, China. qier102@hotmail.com
Huang
Peng-Fei
PF
Wang
Hong-Jing
HJ
Bai
Jun-Yue
JY
Zhang
Li-Ying
LY
Zhao
Yu-Qing
YQ
D001224:Aspartic Acid / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D002244:Carbon / Q000737:chemistry*; D002396:Catechols / Q000032:analysis*; D004563:Electrochemistry; D004566:Electrodes; D006873:Hydroquinones / Q000032:analysis*; D010084:Oxidation-Reduction; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D002396:Catechols; D006873:Hydroquinones; D001224:Aspartic Acid; D002244:Carbon; C034221:catechol; C031927:hydroquinone