响应面法优化蛋氨酸锰的合成

Optimization of Methionine Manganese Production by Response Surface Method

以蛋氨酸和一水硫酸锰为原料合成蛋氨酸锰,在单因素试验的基础上,选择氢氧化钠用量、反应温度和反应原料摩尔配比为影响实验结果因素,通过响应曲面中心复合法优化蛋氨酸锰的制备工艺条件,并建立二次回归方程.优化的最佳条件:n(蛋氨酸)∶n(Mn SO4·H2O)=2.006∶1,n(Mn SO4·H2O)∶n(Na OH)=1∶2,反应温度为80℃,产率可达85.37%.采用红外光谱、热重及XRD粉末衍射验证产物发生络合反应且不含结晶水,采用EDTA法和凯氏定氮法进行含量分析,得蛋氨酸锰的分子结构式为Mn(C5H11O2NS)2.

On the basis of a single-factor experiment, the affecting factors of the amount of NaOH, reac-tion temperature and molar ratio of raw material for the reaction are chosen. Synthesized for complex of me-thionine manganese by the raw materials of methionine and manganese sulfate monohydrate, through the re-sponse surface center methodology to optimize the reaction conditions：n （methionine）∶n （MnSO4＆#183;H2O） =2. 006∶1 and n （MnSO4＆#183;H2O）∶n （NaOH） = 1∶2, reaction temperature at 80 ℃, the yield can reach 85. 37%, and a quadratic regression equation is established. The composition of the complex is charac-terized by content analysis, infrared spectra, thermogravimetric and XRD powder diffraction analysis. It is observed that the complex does not contain water of crystallization, and that content analysis of the complex by EDTA complexometric titration and kjeldahl determination obtains the formula of manganese methionine as Mn （ C5 H11 O2 NS） 2 .