目的建立固相萃取反相高效液相色谱法测定人血浆麦考酚酸(MPA)浓度，探讨MPA与其代谢产物间的转化。方法用固相萃取法处理样品，以泼尼松为内标物，C₁₈硅胶键合相为固定相，甲醇-四氢呋喃-水(60∶2∶50)作流动相，在波长254 nm处紫外定量检测。结果MPA浓度在0.2～40 μg·mL^-1范围内与色谱峰高呈良好线性关系，血浆MPA回收率为92.3%～103.1%，绝对回收率为50.2%～53.7%。最低检测极限为0.2μg·mL^-1，批内与日间(n＝5)RSD为3.34%和4.70%。结论本法用于MPA测定具有准确、灵敏、简便等特点，能满足临床常规血药浓度监测。

OBJECTIVE To determine the concentration of mycophenolic acid (MPA) in plasma using a solidphase extraction and reversed phase high performance liquid chromatography.METHODS A solution of prednisone as the internal standard was added to a 0.2 mL plasma aliquot.The resulting sample was treated with water and dilute HCl and applied to a C₁₈solid phase extraction column,a C₁₈column (7μmparticle size,250mm×4.6mmID) was used with the temperature at 40℃.The mobile phase was consisted of methanol tetrahydrofuran water (60∶2∶50).The UV detection was at 254 nm. RESULTS The quantification limit was 0.2μg·mL^-1and the linear range was over 0.2～40μg·mL^-1.The coefficients of variation of within day and between day at 0.2μg·mL^-1level were 3.34% and 4.70%,respectively.The recoveries of MPA were 92.3%～103.1%. CONCLUSION The method is reproducible,accurate and specific for MPA and can be used in routine determination.