目的 利用响应面分析和增强Donnan效应耦合技术对苦参碱的纳滤浓缩工艺进行优化。方法 以苦参碱及总生物碱截留率为指标，在明确操作压力、温度、平衡体积等因素影响的基础上，采用Box-Behnken中心组合设计建立数学模型，考察截留相对分子质量、指标成分质量浓度、pH值，得出各因素对截留率的影响程度，设定溶液pH值6~7，以乙醇体积分数调节苦参碱与纳滤膜间的Donnan效应，优选纳滤浓缩参数。结果 乙醇体积分数与生物碱截留率呈正相关，优选出纳滤浓缩参数为纳滤膜截留相对分子质量150，pH值6.19，苦参碱质量浓度204.3 μg/mL，总生物碱质量浓度603.1 μg/mL，乙醇体积分数10%，苦参碱截留率为94.41%，总生物碱截留率97.63%。结论 以乙醇溶液调节Donnan效应与响应面法相结合，可用于优选中药纳滤浓缩的参数，为热敏性中药成分的纳滤浓缩提供基础。

Objective Response surface analysis and regulating Donnan effect methodology were used to optimize the matrine concentration by nanofiltration techonology. Methods On the basis of single factor experiment results, molecular weight cut-off (MWCO) of nanofiltration membrane, concentration and pH were selected as influencing factors to evaluate the retention rate of matrine and total alkaloids with Box-Behnken central composite experiment design, and then, the optimal concentration parameters were calculated in the conditions of pH 6-7 to regulate Donnan effect between alkaloids and nanofiltration membrane. Results The retention rate of matrine was of positive relevance with the ethanol concentration. The optimal concentration parameters were as follows:cutting off molecular weight of 150, pH of 6.19, concentration of 204.3 μg/mL, ethanol concentration of 15%, the retention rate of matrine and total alkaloids were 94.41% and 97.63%, respectively. Conclusion The combination of ethanol regulation Donnan effect and response surface analysis can well optimize the concentration process of S. flavescens extract by nanofiltration, and the results provide the references for nanofiltration concentration for heat-sensitive Chinese materia medicia.

国家自然科学基金资助项目（81503258）；江苏省自然科学基金青年基金资助项目（BK20151005）；江苏省中医药局科技项目（YB2015009）