Validation of a capillary electrophoresis method for determination of 5-aminolevulinic acid and degradation products

A capillary electrophoresis method was developed for simultaneous quantification of 5-aminolevulinic acid (ALA) and its degradation products 2,5-dicarboxyethyl-3,6-dihydropyrazine and 2,5-dicarboxyethylpyrazine in aqueous solution within a total analysis time of 9 min. The optimized method was validated with respect to specificity, precision, linearity, limits of detection and quantitation, and robustness. The degradation products were quantified with respect to the ALA peak. A related micellar electrokinetic chromatography method, involving the addition of sodium dodecylsulfate to the running buffer solution, was applied for direct injection of an oil-in-water emulsion containing ALA, i.e. without sample pretreatment. (C) 2000 Elsevier Science EX All rights reserved.