为了探究桑叶中槲皮素含量的测定方法，应用荧光分光光度法进行了实验研究，分析了相应的实验操作参数。以槲皮素标准品为对照，分别研究了乙醇体积分数、静置时间、静置温度、质量浓度5%硝酸铝溶液的加入量和pH值对槲皮素荧光强度的影响。在单因素试验的基础上，利用三因素三水平响应面实验设计对各影响因素的显著性及其交互作用进行了优化分析。研究表明，最佳测定条件为：乙醇体积分数为100%、静置时间为60 min、静置温度为13 ℃。在此条件下测得桑叶中槲皮素的含量为（41.92±0.11）mg/g，相对标准偏差为0.34%。建立槲皮素标准曲线的回归方程为 y=240.14x+7.0952，相关系数R2为0.9950，线性范围在0~1.5×10-2 mg/mL之间良好，适合桑叶中槲皮素含量的测定。

To explore a new method for determining quercetin content in mulberry leaf, fluorescence spectrometry was used and corresponding operational parameters were discussed. The effects of ethanol volume fraction, static time, static temperature, addition of 5% Al(NO3)3 solution and pH value on fluorescence intensity of quercetin were studied with quercetin standard as reference. On the basis of single-factor experiments, significance analysis and interaction effects of various factors were optimized by response surface methodology. The results indicated that optimal detection conditions of quercetin content in mulberry leaf were ethanol concentration 100%, static time 40 min and static temperature 13 ℃. Quercetin content in mulberry leaf was measured of (41.92±0.11) mg/g and the relative standard deviation was 0.34% under above conditions. Established linear regression equation of quercetin standard curve was y=240.14x+7.0952, and the correlation coefficient was R2=0.9950 with a linear range of 0~1.5×10-2 mg/mL. This method was suitable for detection of quercetin content in mulberry leaf.

吉林大学开放性创新实验项目（456OEP01）；吉林大学基本科研业务费项目（450060487500）；吉林省科技发展计划项目(20120717)