Open AccessSelective Determination of Epinephrine in the Presence of Ascorbic Acid and Dopamine Using a Glassy Carbon Electrode Modified with Valine
Author(s) -
Xia Li,
Meifeng Chen,
Xuli Ma,
Xianfu Lin
Publication year - 2010
Publication title -
international journal of chemistry
Language(s) - English
Resource type - Journals
eISSN - 1916-9701
pISSN - 1916-9698
DOI - 10.5539/ijc.v2n1p206
Subject(s) - chemistry , ascorbic acid , detection limit , electrode , cyclic voltammetry , electrochemistry , selectivity , analytical chemistry (journal) , glassy carbon , inorganic chemistry , nuclear chemistry , catalysis , chromatography , organic chemistry , food science
A glassy carbon electrode (GCE) modified with valine was used for the sensitive volt metric determination of epinephrine (EP). The electrochemical response characteristics of the modified electrode toward EP, ascorbic acid (AA) and dopamine (DA) were investigated by cyclic voltammetry (CV). The results show an efficient catalytic activity of the electrode for the electro-oxidation of EP, which leads to an improvement to the reversibility of the electrode response. The effect of pH and potential sweep rate on the mechanism of the electrode process was investigated. The modified electrode exhibits an efficient electron mediating behavior along with well-separated oxidation peaks for EP, AA, and DA. Under the optimum pH of 7.0 in phosphate buffer solution(PBS), the CV anodic peak current showed a linear relation versus EP concentration in the range of 4.5×10-6~1.0×10-5mol·L-1 and 1.0×10-5~1.4×10-4 mol·L-1, with correlation coefficients of 0.9997 and 0.9942. The detection limit is 7.6×10-7 mol·L-1. High sensitivity and selectivity, submicromolar detection limit, high reproducibility, along with ease of preparation and regeneration of the electrode surface by simple polishing make this method suitable for the determination of EP in pharmaceutical and clinical preparations