目的 基于传质系数（k）-孔道占位的内在相关性，建立纳滤膜有效截留相对分子质量（M）的计算方法。方法 测量0.2、0.4、0.6、0.8、1.0、1.2 MPa压力下水、不同体积分数甲醇和乙醇的膜通量，计算相应条件下的k，拟合标准纳滤膜下k与膜孔半径（r_S）的幂函数方程，以水为参照，计算甲醇和乙醇溶液环境下的有效膜孔半径（r_S）和有效M，根据孔道占位比例（P）＝(M_水－M_醇)/M_水，计算不同体积分数甲醇、乙醇的P，并结合不同存在状态辛弗林的截留行为，构建有效M、孔径评价曲线和辛弗林分离行为综合评价方法，分析待测纳滤膜质量。结果 发现k与r_S的幂函数成立，相关性系数大于0.98，随着甲醇、乙醇体积分数的升高，P增加，纳滤膜有效M下降。待测纳滤膜因长时间使用，其有效M、P及辛弗林截留率均发生改变。结论 建立了纳滤膜有效M的计算方法，可以对纳滤膜质量进行系统评价，为制药企业的纳滤膜标准化应用提供了技术支撑。

Objective To explore the calculation method of effective molecular weight cut-off (M) of nanofiltration membranes based on the intrinsic correlation between the mass transfer coefficient (k) and the aperture occupying effect. Methods Measure The membrane flux of different volume fractions of methanol and ethanol in water at pressures of 0.2, 0.4, 0.6, 0.8, 1.0, 1.2 MPa was measured, the k under corresponding conditions was calculated. The power function equation of k and membrane pore radius (r_S) under standard nanofiltration membranes was fitted, and the effective membrane pore radius (r_S) and effective M under methanol and ethanol solution environments was calculated using water as a reference. The aperture occupying proportion (P) of methanol and ethanol with different concentrations was calculated based on P = (M_water－M_{methanol or ethanol})/M_water and effective M of nanofiltration membrane, aperture evaluation curve and synephrine separation behavior was determined comprehensively with the interception behavior of synephrine in different states to analyze the quality of nanofiltration membrane. Results The power function correlation coefficient of k and r_S was greater than 0.98. With the increase of methanol and ethanol concentration, P increased, and effective M of nanofiltration membrane decreased. The effective M, P and synephrine rejection rate of the nanofiltration membrane changed due to long-term use. Conclusion This article establishes a calculation method for effective M of nanofiltration membranes, which can systematically evaluate the quality of nanofiltration membranes and provide technical support for the standardized application of nanofiltration membranes in pharmaceutical enterprises.

国家自然科学基金资助项目（82274106）；江苏省自然科学基金面上项目（BK20211303）；2023年江苏省研究生科研与实践创新项目（KYCX23_2047）；2022年国家级大学生创新创业训练计划项目（103152022105）