Determination of Crude Drug Di-phenyl-di-(2,4-difluobenzohydroxamato) tin and Its Related Substances by HPLC

OBJECTIVE To establish a method to determine the content of crude drug di-phenyl-di-(2,4- diflurobenzohydroxamato)tin (DPDFT) and its related substances by RP-HPLC. METHODS The HPLC system was adopted with Diamonsil C₁₈(250 mm× 4.6 mm, 5 µm) as the stationary phase. The mobile phase was consisted of methanol-water (20∶80, adjusted to pH 3.0 with phosphoric acid) with the flow rate of 0.8 mL·min^-1 and column temperature was 25 ℃. The detection wavelength for determination of contents and related substances were set at 228 nm and 246 nm, respectively. RESULTS Under the selected chromatographic conditions, related substances and degraded substances were completely separated from DPDFT. The average recovery was 99.0 % and the RSD was 0.65%(n=9). The linear range was 1.7-150 µg·mL^-1, and the regression equation was A=1.65×107C-3 286 (r=0.999 9). The limit of detection was10 ng. CONCLUSION The analytical method was simple, quick, accurate, sensitive and selective for the determination of crude drug DPDFT and its related substances.