微波消解光度法测定催化剂中镍

APPLICATION OF MICROWAVE DIGESTION TO THE SAMPLE DISSOLUTION IN PHOTOMETRIC DETERMINATION OF NICKEL IN CATALYSTS

采用微波消解系统消解催化剂样品 ,考察了微波消解时酸的用量、消解时间、功率和压力对消解效果的影响 ,选择了微波消解的最佳工作参数。用常规吸光光度法测定催化剂中镍含量 ,其相对误差小于 3.6% ,相对标准偏差 (n =5 )小于 2 .2 % ,与常压溶样方法测定的结果吻合。试验表明 ,该方法省时、省酸 ,操作简单 ,减少沾污 ,改善工作环境 。

It is reported that in the photometric determination of nickel in catalysts, dissolution of sample is improved by using microwave digestion technique. According to the species of the catalyst, sulfuric acid (1+1) or mixed acid (H 2SO 4∶H 3PO 4∶H 2O=40∶12∶48) together with few drops of HF is added to the sample in a closed digestion vessel and then digested in a microwave oven. The parameters i.e. the power, pressure and time for microwave digestion are optimized. By comparing with the ordinary dissolution method, consistent analytical results are obtained. The microwave digestion technique has the predominant features of less acid and less time are needed, and in addition, environmental contamination is remarkably reduced. The nickel content in the sample solution is finally determined by the dimethylglyoxime photometric method. The RSD found is less than 2.2%.