Article

Selective determination of uric acid in the presence of ascorbic acid at poly(p-aminobenzene sulfonic acid)-modified glassy carbon electrode

People’s Hospital of Gansu Province Lanzhou 730000 People’s Republic of China
Journal of Applied Electrochemistry (Impact Factor: 2.15). 12/2009; 39(12):2323-2328. DOI: 10.1007/s10800-009-9916-0

ABSTRACT The electrocatalytic behavior of uric acid has been investigated with a glassy carbon electrode modified with p-aminobenzene sulfonic acid through electrochemical polymerization. This resulting electrode shows an excellent electrocatalytic
response to uric acid and ascorbic acid, with a peak-to-peak separation of 0.267V in a 0.1molL−1 phosphate buffer solution (PBS) at pH 7.0. These results indicate that the proposed electrode can eliminate the serious interference
of ascorbic acid, which coexists with uric acid in body fluids. Differential pulse voltammetry (DPV) was used for detecting
uric acid with selectivity and sensitivity. The anodic peak current of uric acid was proportional to its concentration in
the range of 1.2×10−7–8.0×10−4molL−1, with a detection limit of 4.0×10−8molL−1. The proposed method has been applied with satisfactory results to the determination of uric acid in human urine without
any pretreatment.

0 Followers
 · 
109 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Glassy carbon electrode was modified with multi-walled carbon nanotubes, electropolymerized 4-amino-3-hydroxynaphthalene sulfonic acid, and their layer-by-layer composite. The electrodes were used to study the oxidation of an important fish spoilage indicator, histamine. Enhanced current responses and lower peak potentials were observed for histamine oxidation at modified electrodes compared to the bare electrode. Among the modified electrodes, a better catalytic response was observed using the multi-walled carbon nanotubes coated polymer modified glassy carbon electrode. This composite electrode was employed for the analytical determination of histamine after experimental parameters were optimized. Under optimum conditions, the oxidation peak current increased linearly with the concentration of histamine over the range of 1.0 × 10−7 to 1.0 × 10−4 M. The calculated limit of detection (3σ) and limit of quantitation (10σ) were 7.62 × 10−8 M and 2.54 × 10−7 M, respectively. The electrode showed excellent repeatability (2.80%) and reproducibility (4.60%) for measurements at 10.0 × 10−6 M histamine. The method was also successfully applied for the determination of histamine in fish muscle extract and spiked sample recovery results were in the range of 96.6–102.9%.
    Synthetic Metals 05/2014; 191:135–140. DOI:10.1016/j.synthmet.2014.03.005 · 2.22 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A sensitive amperometric hydrogen peroxide (HP) sensor was constructed based on silver nanoparticles/poly(2-(N-morpholine) ethane sulfonic acid) (PMES) modified glassy carbon electrode. PMES and silver nanoparticles were orderly introduced to the surface of the electrode by electrochemical methods and characterized by cyclic voltammetry, scanning electron microscopy, and X-ray powder diffraction. The fabricated electrode showed a good electrocatalytic activity toward the reduction of HP with a line range from 0.6 μM to 0.54 mM and a detection limit of 0.18 μM. In addition, the sensor exhibited favorable reproducibility and good long-term stability, and was applied to determine HP in real sample with satisfactory result.
    Journal of Applied Electrochemistry 12/2011; 41(12). DOI:10.1007/s10800-011-0364-2 · 2.15 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The electrochemical behaviors of rutin at a poly(p-aminobenzene sulfonic acid) modified glassy carbon electrode (PABSA/GC) have been investigated. Rutin can generate a pair of well-defined redox peaks at the PABSA/GC located at 0.440 V (E(pa)) and 0.396 V (E(pc)) (vs. saturated calomel electrode (SCE)), respectively. The results indicate that the reaction involves two electrons transfer, accompanied by two protons and the electrochemical process is controlled by adsorption. The electrochemical parameters of rutin on the modified electrode were calculated with the results of the charge transfer coefficient (alpha), the number of electron transfer (n) and the electrode reaction rate constant (k(s)) as 0.61, 2.08 and 2.18 s(-1), respectively. Under the selected conditions, the oxidation peak current was linear to the rutin concentration over the range of 2.5x10(-7)-1.0x10(-5) M with a detection limit of 1.0x10(-7) M. The proposed method has been successfully applied to the determination of compound rutin tablets with no interference from the coexisting ascorbic acid.
    Chemical & pharmaceutical bulletin 04/2010; 58(4):475-8. DOI:10.1248/cpb.58.475 · 1.38 Impact Factor