目的　介绍一种应用二阶导数紫外光谱测定尿和血浆中华法林的新方法。方法　尿和血浆用甲醇 /醋酸缓冲液稀释后 ,通过PT -C18柱进行固相萃取 ,用氯仿洗脱。洗脱液用NaOH溶液反提 ,测定NaOH溶液的二阶导数光谱 ,用 32 8nm处的吸光度值时行定量。结果　尿中华法林的检测下限为 0 5～ 1mg/L ,血浆则为 2～ 4mg/L。 结论　该方法可用于大剂量中毒检测 ,亦可用于微量血药浓度检测。 Objective To introduce a new method for the determination of warfarin in urine and plasma by second derivative UV spectrophotometry. Methods Urine and plasma were diluted with methanol / acetate buffer and subjected to solid phase extraction on a PT-C18 column eluting with chloroform. The eluent was back-extracted with NaOH solution and the second derivative of the NaOH solution was measured. The absorbance at 32 8 nm was quantified. Results The lower limit of detection of warfarin in urine was 0 5 ~ 1 mg / L and plasma was 2 ~ 4 mg / L. Conclusion The method can be used for detection of high-dose poisoning, but also for the detection of trace blood concentration.