Journal of the Serbian Chemical Society 2010 Volume 75, Issue 12, Pages: 1685-1699
https://doi.org/10.2298/JSC100311134E
Full text (
331 KB)
Cited by
Voltammetric determination of dopamine in the presence of uric acid using a 2-hydroxy-1-(1-hydroxynaphthyl-2-azo)- naphthalin-4-sulfonic acid modified glassy carbon electrode
Ensafi Asghar Ali
Dadkhah-Tehrani Samira
Rezaei B.
A polymerized film of 2-hydroxy-1-(1-hydroxynaphthyl-2-azo)-
naphthalin-4-sulfonic acid (HHNANSA) was prepared at the surface of a glassy
carbon electrode by electropolymerization. The modified electrode was used
for the simultaneous determination of dopamine (DA) and uric acid (UA). The
electrochemical behaviors of the compounds at the surface of the modified
electrode were studied using cyclic voltammetry, chronoamperometry, and
square wave voltammetry (SWV). The experimental results indicated that the
modified electrode exhibited an efficient electrocatalytic activity towards
the oxidation of DA and UA, with a peak separation of about 140 mV at pH 5.0.
Using chronoamperometry, the catalytic reaction rate constant was measured
and found to equal to 1.23 × 104 mol-1 L s-1. At pH 5.0, the catalytic peak
currents linearly depended on the DA and/or UA concentrations in the range of
1.0 - 300 μmol L-1 DA (two linear segments with different slopes) and 6.7 -
20 μmol L-1 UA, using SWV. The detection limits for DA and UA were 0.25 μmol
L-1 and 1.17 μmol L-1, respectively. The RSD % for 40.0 and 140.0 μmol L-1 DA
were 1.9 % and 2.2 %, respectively, whereas for 10.0 and 20.0 μmol L-1 UA,
they were 1.8 % and 1.2 %, respectively. The modified electrode showed good
sensitivity, selectivity, and stability. It was successfully applied for the
determination of DA and UA in real samples, such as drugs and urine.
Keywords: 2-hydroxy-1-(1-hydroxynaphthyl-2-azo)-naphthalin-4-sulfonicacid, simultaneous determination, dopamine and uric acid, voltammetry