A method using RP-HPLC with fluorescence detector was developed for determining the intracellular and extracellular concentrations of Doxorubicin (Dox) in K562/A cells. To analyze the intracellular concentration of Dox, a Lichrospher C₁₈ column maintained at 35℃ was used, and the mobile phase consisted of methanol-0.01% acetic acid solution (50:50, V/V) at the flow rate of 1.0 mL/min. A Lichrospher C₁₈ column maintained at 35℃ was used to analyze the extracellular concentration of Dox, and the mobile phase consisted of Methanol-0.01% acetic acid solution (55:45, V/V) at the flow rate of 0.8 mL/min. Daunorubicin was used as the internal standard, and the excitation wavelength and emission wavelength were 495 nm and 560 nm respectively. The proposed method has been verified to be simple, accurate and sensitive. It has low limit of determination, wide linear range, satisfied precision, and good mean recovery. For multi-drug resistance cancer cells, the dynamic status of the intracellular and extracellular concentrations of Dox could be investigated by using this method.

Key words: HPLC, Doxorubicin, MDR cancer cell, K562/A cell