石墨炉原子吸收光谱法测定水中微量砷

Determination of Trace Arsenic in Water by Graphite Furnace Atomic Absorption Spectrometry

通过一系列条件试验,确定用石墨炉原子吸收光谱法测定水中微量砷时的最佳酸度为0.2%(体积比) HNO3,最佳灰化温度为1 300℃,最佳原子化温度为2 300℃.选择硝酸镁为基体改进剂,可有效防止砷在灰化过程中的损失,从而增强吸收信号.本方法不仅具有较高的精密度(标准偏差为0.43%)和较高的回收率(90%～95%),而且操作简便、快速、自动化程度高,可用于水中砷的准确检测.

The working condition in the determination of trace arsenic in water by graphite furnace atomic absorption spectrometry （GFAAS） is investigated. The optimum acidity, the ashing temperature and the atomization temperature are determined to be 0.2% HNO3, 1300℃ and 2300℃, respectively. The Using of Mg（ NO3 ）2 as the matrix modifier will reduce the losing of arsenic during the ashing process and enhance absorption signal. The method can be used to analyze trace arsenic in water accurately,with a higher precision and a standard deviation of 0. 43% and a higher recovery rate （90% -95% ）, as well as simple operation procedure, speediness and high automatization.