Simultaneous voltammetry detection of dopamine and uric acid in human serum and urine with a poly(procaterol hydrochloride) modified glassy carbon electrode.

In the present study, procaterol hydrochloride (ProH) was successfully electropolymerized onto a glass carbon electrode (GCE) with simply cyclic voltammetry scans to construct a poly(procaterol hydrochloride) (p-ProH) membrane modified electrode. Compared with the bare GCE, much higher oxidation peak current responses and better peak potentials separation could be obtained for the simultaneous oxidation of dopamine (DA) and uric acid (UA), owning to the excellent electrocatalytic ability of the p-ProH membrane. And it's based on that a square wave voltammetry (SWV) method was developed to selective and simultaneous measurement of DA and UA. Under the optimum conditions, the linear dependence of oxidation peak current on analyte concentrations were found to be 1.0-100 µmol/L and 2-100 µmol/L, giving detection limits of 0.3 µmol/L and 0.5 µmol/L for DA and UA, separately. The as prepared modified electrode shows simplicity in construction with the merits of good reproducibility, high stability, passable selectivity and nice sensitivity. Finally, the proposed p-ProH membrane modified electrode was successfully devoted to the detection of DA and UA in biological fluids such as human serum and urine with acceptable results.

Sensitive determination of bromhexine hydrochloride based on its quenching effect on luminol/H2 O2 electrochemiluminescence system.

In this paper, the electrochemiluminescence (ECL) behavior of luminol/H2 O2 system in the presence of bromhexine hydrochloride (BrH) was investigated. It was found that the ECL intensity of luminol/H2 O2 system on a platinum electrode could be intensely quenched by BrH owing to the scavenging superoxide radical ability of BrH, and therefore the sensitive determination of BrH was possible. Under optimal conditions, the quenched ECL intensity was linear to the concentration of BrH in a wide range of 0.08 to 500 µM, with a detection limit of 0.02 µM (signal-to-noise ratio (S/N) = 3). This ECL method possessed the merits of rapid, simple and sensitive, and was successfully applied to the BrH quantification in pharmaceutical preparations with satisfactory recoveries of 91.0 ± 4.0 to 106.5 ± 3.4%. The possible route of the quenched ECL of luminol/H2 O2 in the presence of BrH was also discussed.