尿中钴的石墨炉原子吸收光谱直接测定法

Determination of Cobalt in Urine by Graphite Furnace Atomic Absorption Spectrometry

目的探讨直接进样石墨炉原子吸收光谱测定尿中钴的方法。方法采用氯化钯-磷酸氢二铵-硝酸混合基体改进剂,提高灰化温度,减少原子化阶段的气相干扰,并探讨了最佳分析条件。结果含15%的氯化钯、磷酸氢二铵和硝酸作基体改进剂,在1 200℃灰化,2 450℃原子化条件下,该方法的线性范围为0～75μg/L,r>0.999。回收率为96.0%～98.0%,RSD为3.5%～6.5%,最低检测浓度为1.5μg/L。背景吸收值在0.05以下,能有效控制背景吸收在氘灯校正的范围之内。与极谱法同时测定16件尿样,测定结果差异无统计学意义(t=0.59,P>0.05)。结论该法操作简便,线性范围宽,灵敏,结果准确,空白低,抗干扰能力较强;适用于作业场所人员尿钴含量测定。

Objective To develop a method for the determination of cobalt in urine by graphite furnace atomic absorption spectrometry （GFAAS）. Methods Using the matrix modifier to find the best condition by improving the cineration temperature and reducing the interference of gas phase in atomization stage. Results The best cineration temperature and atomization temperature was 1 200 ℃ and 2 450 ℃ respectively, taking 15% PdCl2, NH3H2PO4 and HNO3 as the matrix modifier. The background absorb value was less than 0.05. The linear range was 0～75 μg/L, the correlation coefficient was over 0.999, the average recovery rate was 97.2%, the relative standard deviations were 3.5%～6.5%, the detection limit was 1.5 μg/L. The result of 16 urine samples determined with the present method showed no significant difference compared with that by using polarography. Conclusion This method is sensitive, accurate, simple and is applicable to the determination of cobalt in urine.