Determination of folic acid by high-performance liquid chromatography with direct electrogenerated chemiluminescence reaction.

In our present work, it was found that the electrooxidation of folic acid (FA) was accompanied by electrogenerated chemiluminescence (ECL) emission. Out of the four inorganic salts, NaNO(3) solution was found to be a suitable supporting electrolyte for the ECL emission of FA. Coupled with high-performance liquid chromatography separation, this simple ECL method was used for post-column determination of FA. Under the optimal conditions, the ECL intensity has a linear relationship with the concentration of FA in the range of 1.0 x 10(-7) to 1.0 x 10(-5) g/mL and the detection limit was 5 x 10(-8) g/mL (signal-to-noise ratio = 3). Application of the present method to the analysis of FA in human urine proved feasible.