Electrochemical behavior of 5-fluoro-1H-pyrimidine-2 on an ionic liquid modified carbon paste electrode

Abstract

In this paper an ionic liquid (IL) 1-butylpyridinium hexafluorophosphate (BPPF₆) modified carbon paste electrode was constructed and further used to establish a sensitive method for the detection of 5-fluoro-1H-pyrimidine-2 (5-FU). Compared with the carbon paste electrode (CPE), a single well-defined irreversible oxidation peak of 5-FU appeared on the IL-CPE with a great improvement of the electrochemical response, which was due to the presence of a high ionic conductive ionic liquid in the electrode that exhibited accumulation and electrocatalytic ability. The electrochemical parameters of 5-FU on the IL-CPE were calculated with the electron transfer coefficient (α) as 0.62 and the diffusional coefficient (D) as 7.02 × 10⁻⁵ cm² s⁻¹. Under the optimal conditions, the oxidation peak current was linear to 5-FU concentration in the range from 5.0 × 10⁻⁷ to 8.0 × 10⁻⁴ mol L⁻¹ with a detection limit of 1.3 × 10⁻⁸ mol L⁻¹ (3σ). Good selectivity to 5-FU detection was observed without the interference of coexisting substances and the method was further applied to determination in injection samples with satisfactory results.