目的建立人血浆中盐酸二甲双胍高效液相色谱测定方法。方法取200μL血浆,加入雷尼替丁(ranitidine)为内标,以400μL乙腈沉淀蛋白,上清液与二氯甲烷混合离心后,取上层水相进样分析。流动相:乙腈-0.05 mol·L^-1NaH₂PO₄-0.05 mol·L^-1Na₂HPO₄(75∶25∶5);流速1.0 mL·min^-1,紫外检测波长236 nm,室温操作。结果二甲双胍与内标分离良好,保留时间分别为12.5和11.6 min。标准曲线范围0.025～4.0 mg·L^-1,线性良好(r=0.999 5,n=5),批间RSD为2.46%～4.96%(n=5),批内RSD为1.85%～3.97%(n=10),最低检测限为0.01 mg·L^-1`。二甲双胍在检测过程中保持稳定。结论本方法取样量小,操作快速简便,专一性强,灵敏度高,可满足药动学研究需要。

OBJECTIVE To develop a HPLC assay for the determination of metformin in human plasma.METHODS 400 μL acetonitrile was added to 200 μL plasma sample with ranitidine as the internal standard for precipitating protein.The supernatant was washed with dichoromethane and 20 μL aqueous was injected to HPLC.The separation was performed on a Zorbax Rx-Sil column(4.6 mm×250 mm,5 μm).The mobile phase consisted of acetonitrile,0.05 mol·L^-1NaH₂PO₄ and 0.05 mol·L^-1Na2HPO4(75∶25∶5) at the flow rate of 1.0 mL·min^-1.The detection wavelength was at 236 nm.RESULTS An excellent linearity(r=0.999 5,n=5) was obtained over the range of 0.025～4.0 mg·L^-1,and the limit of detection was 0.01 mg·L^-1.The RSDs for 0.05,1.0 and 3.0 mg·L^-1 check samples were 2.46%～4.96% for intra-run validation(n=5),and 1.85%～3.97% for inter-run validation(n=10),respectively.CONCLUSION The improved method is sensitive,specific,reproducible and easy to process.It is practical and suitable for the pharmacokinetic study of metformin.