提出了一种石墨炉原子吸收光谱法测定环境水样中痕量镉的新方法.详细研究了石墨炉的灰化、原子化温度及时间,对环境水样中常见共存离子的影响进行了考察.在最优的试验条件下,新方法的检出限为0.13ng/mL,相对标准偏差为3.1%(c=2.0ng/mL,n=7),方法的线性范围为0-10ng/mL.新方法应用于环境水样中镉的测定,样品加标回收率为94.9%~107.5%.同时,为了验证方法的准确性,将所提出的新方法应用于标准参考物GBW08608中镉的分析,测定结果与标准参考值吻合良好.
A new method for the determination of cadmium (Cd) in water samples tested by graphite furnace atomic absorption spectrometry (GFAAS) was developed. Ashing temperature and time, atomization temperature and time, the effect of potential interference of coexisting ions on the determination of Cd were investigated in detail. Under the optimized conditions, the limit of detection (LOD) for Cd was 0. 13 ng/mL, the pre- cision relative standard deviation (RSD) for seven replicate measurements of 2.0 ng/mL Cd was 3.1% , and the calibration curve was obtained with a series of Cd standard solutions ranged in 0 - 10 ng/mL. The developed method was applied to the determination of Cd in water samples and the recoveries for the spiked samples were in the range of 94.9% - 107.5%. For validation, the developed method was also applied to the determination of Cd in a certified reference material of GBW08608 and the determined value was in good agreement with the certified one.