2,4-二氨基甲苯前处理方法的改进研究

Research on the Improvement of the Pretreatment Method of 2,4-Diaminotoluene

通过对浸泡液、提取溶剂、萃取条件、水的去除方式和过量衍生剂的消除方式的优化,改进2,4-二氨基甲苯的前处理方法。结果表明,用水热提取复合包装膜袋中2,4-二氨基甲苯,浸泡液在加盐和碱条件下用甲苯萃取,浓缩至近干后用三氟乙酸酐进行衍生化,取出后氮吹至干,用乙酸乙酯定容后再用GC-ECD测定,回收率较国标方法萃取明显提高。通过加盐降低二氨基甲苯在水中的溶解度、加碱增大提取液的p H值,有效地提高萃取效率;采用氮吹的方法消除水和过量衍生剂的干扰。改进方法后提取效果良好,具有较强的实用性和经济性。

The pretreatment process of 2,4-diaminotoluene was improved by carefully optimization of immersion solution,extraction solvent,extraction condition,water removal method and elimination of excess derivatives. 2,4-diaminotoluene were immersed by boiling water,extracted by toluene with salt and alkali additive,concentrated to nearly dry then derivatived by trifluoroacetic annydride,then blow to dry by nitrogen,definited by ethyl acetate and determinated by GC-ECD. The recovery rate was significantly improved compared with the national standard method. Methods to reduce the solubility of 2,4-diaminotoluene in water by adding salt,increased p H value by adding alkali,effectively improved the extraction efficiency; the interference of water and excess derivatives was eliminated by nitrogen blowing. The method has good effect,and has strong practicability and economy.