Determination of 6-Hydroxykynurenic Acid in Ginkgo Preparation by HPLC

OBJECTIVE To establish the method of determining the 6-hydroxykynurenic acid (6-HKA) content with HPLC. METHODS XDB-C₈ column(4.6 mm×250 mm, 5 μm) was used. Mobile phase was mixture of 0.1% phosphoric acid-CH₃CN-CH₃OH(94∶5∶1). The flow rate was 1.0 mL·min^-1. The UV detector was operated at 350 nm. Tablets were comminution, dissolution with 50% methanol, and determination after filtration. RESULTS The linear range of 6-HKA was 5.025-100.5μg·mL^-1(r=1.000 0); the average recovery was 99.86%. The content of 6-HKA in 6 batches of Ginkgo tablets was 0.22%-0.35%. CONCLUSION The method is simple, the result is accurate, and the reproducibility is good.