采用气相色谱电子捕获检测法测定５单硝酸异山梨酯的血药浓度。样品经乙醚—正己烷混合溶剂提取，三氟醋酐进行衍生化后，用５％ＳＥ３０硅烷化玻璃填充柱分离，以硝酸异山梨酯为内标，６３Ｎｉ电子捕获检测器检测。此法操作简便，日内、日间误差分别小于４％和６５％，平均回收率为９９６２％±１１９％。在２０～８００ｎｇ·ｍｌ－１血浆浓度范围内呈线性关系（γ＝０９９９５）。最低检测浓度为２０ｎｇ·ｍｌ－１。应用此法研究了１０名健康志愿者单次口服２０ｍｇ５单硝酸异山梨酯片后的药代动力学。 The plasma concentration of isosorbide 5 mononitrate was determined by gas chromatography-electron capture detection. The sample was extracted with diethyl ether-n-hexane mixed solvent. Trifluoroacetic anhydride was derivatized with 5% SE-30 silanized glass column and was separated with isosorbide dinitrate and detected by 63Ni electron capture detector. The method is simple and easy to operate. The daily and intra-day errors are less than 4% and 65%, respectively. The average recovery rate is 9962% ± 119%. In the range of 20 ~ 800ng · ml-1, there was a linear relationship (γ = 09995). The minimum detectable concentration was 2.0ng · ml-1. This method was used to study the pharmacokinetics of 10 healthy volunteers after a single oral administration of 20 mg 5 isosorbide mononitrate tablets.