Tungstate/Pertungstate System Cathodic Indirect Oxidation to Synthesis Hydrophobic Monascus Yellow Colorant
- 2009年第15卷 
以自制SBS-g-(AA/StSO3Na)/SBS-g-DMAEMA双极膜作电解槽阴阳两极室的隔膜,借助正交试验确定阴极电还原氧气产生过氧化氢的最优条件,进而利用钨酸钠/过钨酸钠体系由阴极间接电氧化红曲红制备红曲黄色素.实验表明:以石墨作电极,阳极液为10%硫酸溶液,阴极液为0.5g·L-1红曲红丙酮水溶液,添加钨酸钠(浓度15mmol/L),调节pH至3,在通氧速率65cm3/min,电流密度5.78mA.cm-2下电解2h,阴极平均电流效率可达72.39%.电解产物经红外表征和紫外跟踪分析,证实了红曲红烯键环氧化反应的发生.Using SBS-g-(AA/StSO3Na)/SBS-g-DMAEMA Bipolar Membrane as a separator between the cathode and anode chambers in the electrolysis cell,the optimum conditions of deoxidization of oxygen in cathode were obtained through orthogonal experiment. Then using tungstate/pertungstate as media to indirect electrooxidate hydrophobic monascus red colorant to prepare hydrophobic monascus yellow colorant in cathode. The experiment results show the average current efficiency of cathode was up to 72.39% under the following conditions:that graphite as electrode,10% sulfuric acid as anode electrolyte,0.5 g·L-1 hydrophobic monascus red colorant solution as cathode electrolyte,tungstate concentration:15 mmol/L,pH:3,flow rate of oxygen:65 cm3/min,electrolyze 2 h under the current density of 5.78 mA·cm-2. The FT-IR and UV-VIS results of electrolysis products indicated the epoxidation of hydrophobic monascus red colorant.