GF-AAS Determination of Residual Amount of Chromium in Vacant Gelatin Capsules

Sample of vacant gelatin capsule was digested with nitric acid in a microwave digestor and the content of chromium in the sample solution was determined by GFAAS. The ashing temperature and atomization temperature were set at 900 ℃ and 2 500 ℃ respectively. Linear relationship between values of absorbance and mass concentration of chromium was obtained in the range of 2-30 μg·L-1, with detection limit (3s/k) of 0.103 mg·kg-1. The proposed method was used in the analysis of substantial samples. Recovery was tested by standard addition method, giving results of recovery in the range of 95.9%-102% with RSD′s (n=9) less than 2.0%.