明胶空心胶囊样品经硝酸微波消解,采用石墨炉原子吸收光谱法测定其中铬的残留量。采用灰化温度为900 ℃,原子化温度为2 500 ℃。铬的质量浓度在2~30 μg·L-1范围内与其吸光度呈线性关系,检出限(3s/k)为0.103 mg·kg-1。应用此方法分析了明胶空心胶囊样品。用标准加入法进行回收试验,所得回收率在95.9%~102%之间,测定值的相对标准偏差(n=9)均小于2.0%。

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%.