取粉碎且混匀的样品(0.200 0~0.500 0 g)于聚四氟乙烯(PTFE)消化罐中用硝酸6 mL及过氧化氢2 mL,按预设程序进行微波消解,所得溶液蒸缩至1 mL左右,加水定容至50 mL,供电感耦合等离子体质谱法测定其铝含量。选用钪作为内标元素,外标法定量。铝(Ⅲ)的质量浓度在0.3 mg·L-1以内呈线性。方法的检出限(3S/N)为0.061 μg·L-1。以实样为基体,在3个浓度水平上加入铝(Ⅲ)标准溶液,按方法测定做回收试验。测得回收率在94.0%~101%之间,测定值的相对标准偏差(n=6)在1.4%~2.1%之间。方法应用于测定大米及小麦标准物质(GBW 10010及GBW 10011)中铝量,测定值与认定值相符。

The powdered and homogenized sample (0.200 0-0.500 0 g) was digested with 6 mL of HNO3 and 2 mL of H2O2 in the microwave digestor under pre-set program. The solution obtained was evaporated to ca. 1 mL and made up to 50 mL with water, which was used for ICP-MS determination for its Al-content. Scandium was chosen as the internal standard and the method of external standard curve was used for quantification. Linearity range of mass concentration of Al was found within 0.3 mg·L-1. Detection limit (3S/N) of the method found was 0.061 μg·L-1. Recovery of the method was tested by addition of Al(Ⅲ) standard solution at 3 concentration levels, giving results of recovery in the range of 94.0%-101%, and values of RSD′s (n=6) in the range of 1.4%-2.1%. Two samples of CRM′s (GBW 10010 and GBW 10011) were analyzed by the proposed method for their Al-contents, the results obtained were in consistency with the certified values.