AIM: To establish a rapid analysis method for the determination of
sodium valprate in serum by HPLC after
precolumn derivatization.
METHODS: 2-Bromo-4'-nitroacetophenone was selected as derivative reagent. Cyclohexanecarboxylic acid was used as an internal standard. The analytical column was Nova-pak C 18 column (150 mm×3.9 mm,4 μm). The mobile phase consisted of methanol-water (77∶23,V/V). The detection wavelength was 262 nm and the flow rate was 1 mL·min -1,column temperature was 25℃. RESULTS: The retention time of cyclohexanecarboxylic acid and
sodium valprate was 3.0 and 4.5 min,respectively. The linear range of sodium valprate was 20-180 mg·L -1. The mean relative recovery was 100.2%. The relative standard deviation (RSD) of within day and between day were all less than 3.5%. The method was used for monitoring serum sodium valprate concentration of 230 epileptic patients, 77.8% of the patients who had taken sodium valprate was found the serum concentration in effective level and 22.2% lower or higher than effective level. CONCLUSIONS: This method is found to be rapid, accurate, sensitive and more suitable for clinical practical application.