Determination of the related substances of benzyl hydroxybenzoate by RP-HPLC

An RP-HPLC method was established to separate the related substances of benzyl hydroxybenzoate. The separation was carried out on a Agilent ZORBAX Eclipse Plus Phenyl-Hexyl column. The mobile phase was methonal-0. 1% glacial acetic acid, using linear gradient elution, and the detection wavelength was 254 nm. There was a good linear relationship between 0. 051-101. 88 μg/mL(r=1. 00)and 0. 050-99. 48 μg/mL(r=0. 999 8)for benzyl hydroxybenzoate and p-hydroxybenzoic acid, repectively. The average recovery of p-hydroxybenzoic acid was 100. 3% and the RSD was 0. 95%. The LOQ of p-hydroxybenzoic acid was 0. 24 ng. The detected impurities were also identified by UPLC-Q-TOF. The established method is accurate and reproducible, and could be used for the quality control of benzyl hydroxybenzoate.