Determination of hydroquinone in cosmetic emulsion using microdialysis sampling coupled with high-performance liquid chromatography.

A method based on microdialysis sampling combined with high-performance liquid chromatography (HPLC) has been developed for the determination of hydroquinone in cosmetic emulsion. In microdialysis sampling, using deionized water as perfusate, a probe length of 10mm and dialysis flow-rate of 5 microl min(-1) were found to be the optimum conditions for the analysis. The accuracy (% bias) for intra-day (n=3) and inter-day (n=12, four consecutive days) ranged from -9.