Determination of azelaic acid and potassium azeloycinate diglycinate in cosmetics by HPLC

Objective An HPLC method was established for the determination of azelaic acid and potassium azeloycinate diglycinate in cosmetics.

Methods The samples were extracted with 60 mmol·L^-1 sodium hydroxide water solution-methyl alcohol. After centrifugation and filtration， the analysis of azelaic acid and potassium azeloycinate diglycinate was performed with a SVEA C8（250 mm×4.6 mm， 5 μm） column， using 15 mmol‧L^-1 potassium dihydrogen phosphate solution （pH=3.0） and acetonitrile for gradient elution at a flow rate of 1.0 mL·min^-1. The analytes were detected with UV detector， and quantified by external standard curve.

Results The results showed a good linearity in the range of 5‒1 000 μg‧mL^-1 with correlation coefficients （r） larger than 0.999. The detection limit of azelaic acid and potassium azeloycinate diglycinate （LOD） was 0.020% and 0.015%， respectively. The spiked recoveries were 87.66% to 108.96% with the relative standard deviation （RSD） of 0.6% to 3.3%.

Conclusion The method is simple， rapid and highly sensitive. It is suitable for the determination of azelaic acid and potassium azeloycinate diglycinate in cosmetics.