Determination of free radical reaction products and metabolites of salicylic acid using capillary electrophoresis and micellar electrokinetic chromatography.

Hydroxylated radical products of salicylic acid are often used as a relative measurement in free radical research. Several analytical methods exist to determine the amount of 2,3-dihydroxybenzoic acid and 2,5-dihydroxybenzoic acid. In this study we use capillary zone electrophoresis (CZE) and micellar electrokinetic capillary chromatography (MECC) in order to determine these free radical products. The CZE experiment was optimized with a CZE simulation program HPCESIM in order to achieve an optimal pH. Calibration curves were recorded in the range 10(-6)-10(-4) M and the detection limit was determined. For both CZE and MECC it was 2x10(-7) M. Both methods resulted in a reproducible analysis of salicylate and its hydroxylated free radical products in 6 min.