原子吸收分光光度法测定能力测试样品中痕量金属元素

Determination of Trace Metal Elements in Proficiency Testing Samples by Atomic Absorption Spectrometry

研究用火焰与石墨炉原子吸收分光光度法测定美国NSI公司的能力测试样品中痕量金属元素:Mn、Fe、Pb、Zn、Ag、Cu、Cd.采用加标回收试验判断样品基体干扰程度,加入磷酸二氢胺和硝酸镁作为基体改进剂,降低了石墨炉测定Ag、Cd时的背景吸收,在工作曲线最佳测定范围内提高了测定准确度.该方法测定结果的相对误差<±4%,用于能力检测结果满意。

Trace metal elements shch as Mn,Fe,Pb,Zn,Ag,Cu,Cd in US NSI＇s proficiency testing samples were measured by flame and graphite furnace atomic absorption spectrometry. The recovery tests using spiked samples were used to determine the extent of matrix interference. Ammonium dihydrogen phosphate and magnesium nitrate were added as matrix modifier to reduce the background absorption in the graphite furnace determination of Ag, Cd and to improve the accuracy of test results in the optimum determination range of the working curve. The relative error is 〈±4% by this method and the results are satisfied for proficiency testing.