Abstract
Catecholamines (CAs) are important neurotransmitters and hormones in mammalian species. They are highly reactive and are readily oxidized to aminochromes.
That enables the use of electrochemical method for their determination. In this paper, differential pulse voltammetric (DPV) determination and HPLC with amperometric detection of dopamine (D), epinephrine (E), norepinephrine (NE) and L-Dopa (DOPA) is developed and optimized.
The carbon paste electrode (CPE) prepared of carbon powder CR2 and single-wall carbon nanotubes (SWCNT) (50:50 m/m) was used. The miniaturized body for CPE was used to reduce consumption of all chemicals.
In Britton-Robinson buffer solution pH 6, the limits of detection 1 x 10(-6), 2 x 10(-6), 2 x 10(-6) and 8 x 10(-6) mol dm(-3) have been found for DPV determination of D, E, NE and DOPA, respectively. HPLC was carried out using 0.1 M phosphate buffer pH 3: methanol (95: 5) mobile phase containing 10 mM EDTA.
The above described CPE in a wall-jet arrangement was used for amperometric detection. The limit of detection of each analyte in a mixture was 2 x 10(-6) mol dm(-3).
Practical application of this method on spiked urine samples was verified.