ICP-MS Determination of Aluminum in Wheaten Food with Microwave Assisted Sample Digestion

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.