[Determination of liensinine in plasma by high performance liquid chromatography].

A sensitive method of high performance liquid chromatography (HPLC) for determination of liensinine in plasma is reported. An Ultrasphere Si column, 250 mm x 4.6 mm i.d. with dichloromethaneisopropyl alcohol-diethylamine (75:25:0.2, V/V) as mobile phase at a flow-rate of 1.0 mL/min and UV-detector at 282 nm were used. Neferine was served as the internal standard. Liensinine in plasma was extracted with diethyl ether three times after adding ammonia-ammonium chloride buffer (pH 10). Liensinine was completely separated from nefrine. The retention times of liensinine and neferine were 8.5 and 5.0 minutes, respectively. The calibration line of liensinine was linear in the range of 0.0625-5.0 mg/L (r = 0.9996). The mean recovery was 93.6% with RSD of 1.9%. The precision of intra-day and inter-day for liensinine was in the range of 1.4%-4.1% and the detectable limit was 0.025 mg/L based on a signal-to-noise ratio of 3. The results showed that the method was simple and sensitive.