Abstract: AimTo establish HPLC chiral separation method for ketoprofen enantiomers by using Chirobiotic V chiral seperation phase(CSP) (A) and vancomycin as chiral mobile phase additives (B). MethodsThe separation was first performed on Chirobiotic V CSP with the mobile phase of terahydrofran(THF)-0.5% triethylanine acetate(TEAA) buffer (15∶85) at the flow rate of 0.7 mL·min^-1. When using vancomycin as chiral mobile phase additive, the separation was carried out on C₈ column (150 mm×4.6 mm), the mobile phase was methanol-0.25% TEAA buffer (50∶50), the flow rate was 0.7 mL·min^-1. The effects of the concentration of vancomycin, organic modifier and the pH of the buffer on the resolution of ketoprofen enantiomers were investigated. Also, the feasibility of these two methods to be used as quantitative method was studied. ResultsKetoprofen enantiomers were separated at a baseline level under the chromatographic condition of both methods A and B, the resolution was 2.28 and 2.22, respectively. In method A the linearity of enantiomer was obtained from 0.5 mg·L^-1 to 100 mg·L^-1, the detection limit was 1 μg·L^-1. When using vancomycin as mobile phase additive the system was shown to have a high efficiency. In this system, the assay of enantiomer is linear from 2.5 mg·L^-1 to 250 mg·L^-1. The detection limit was 14.5 μg·L^-1. ConclusionBoth methods can be used to detect optical purity of S-(+)-ketoprofen.