微波消解-ICP-AES用于硅溶胶中杂质元素测定

Determination of Impurity Element Contents in Silica Sol by Microwave Digestion-ICP-AES

采用微波消解方法处理硅溶胶样品,通过设计正交实验研究消解温度、保留时间和消解溶剂对消解效果的影响,优化了微波消解硅溶胶样品的消解参数。并采用电感耦合等离子体原子发射光谱（ICP-AES）法测定硅溶胶中Fe、Na、K杂质元素的含量。结果表明,优化的硅溶胶消解参数为：消解温度为160℃,保留时间为4 min,盐酸及氢氟酸用量分别为2.0和1.0 m L。该方法 Fe、Na、K元素的检出限依次为：0.002、0.002和0.003μg/m L,Fe、Na、K的加标回收率均在97%~103%之间,相对标准偏差（RSD）均小于2%,具有较好的准确度和精密度。方法快速简便、准确可靠,完全能够满足分析要求。

Silica sol samples were treated by microwave digestion method. Influences of digestion temperature, retention time and solvent on the digestion effect were investigated by designing orthogonal test, and the digestion parameters of the microwave digestion were optimized. And then the contents of three impurity elements, including Fe,Na and K in silica sol were determined by atomic emission inductively coupled plasma spectrometry（ICP-AES）. The results show that the optimum digestion parameters are as follows： the digestion temperature 160 ℃,the retention time 4 min and the dosages of the digestion solvent 2 m L HCl and 1 m L HF. The element detection limits of Fe,Na and K are 0.002, 0.002 and 0.003μg/m L respectively, and the recovery rates of ICP-AES method are between 97%~103%, the relative standard deviations（RSD） are lower than 2%. These figures show that the microwave digestion-ICP-AES method has good accuracy and precision. This method is accurate, simple and reliable, which can meet the analysis requirement completely.