Determination of naproxen in human urine by high-performance liquid chromatography with direct electrogenerated chemiluminescence detection

A simple and sensitive liquid chromatographic method coupled with electrogenerated chemiluminescence (ECL) was described for the separation and quantification of naproxen in human urine. The method was based on the ECL of naproxen in basic NaNO₃ solution with a dual-electrode system. Factors affected the ECL emission were investigated. Under the optimal conditions, the ECL intensity has a linear relationship with the concentration of naproxen in the range of 4.0 × 10⁻⁸ g mL⁻¹ to 2.0 × 10⁻⁶ g mL⁻¹ and the detection limit was 1.6 × 10⁻⁸ g mL⁻¹ (S/N = 3). Application of the method to the analyses of naproxen in human urine proved feasible.