RESUMO
AIM: To determine the content of emodin and physcion in rat plasma by nonaqueous RP-HPLC. METHODS: After hydrolysis and extraction, the content of emodin in the plasma was determined by nonaqueous RP-HPLC. The separation was performed on Kromasil C 18 column (250 mm?4.6 mm, 5.0 ?m) with the mobile phase comprised of methanol-acetic acid (99.9∶0.1). The flow rate was 1.0 mL?min -1 and the detection wavelength was at 254 nm. RESULTS: The linear ranges for emodin and physcion were in the range of 0.0425-2.8 ?g?mL -1 and 0.0491-3.14 ?g?mL -1 , respectively. The average recoveries of emodin and physcion were 95.7%-100.1% and 96.2%-99.8%, with corresponding RSD of 1.3% and 1.6% respectively. CONCLUSION: This method is simple, rapid, accurate and reproducible with RP-HPLC to detect rhein in plasma.