石墨炉原子吸收光谱中钐基体的背景吸收研究

The Studies on the Background Absorption of Samarium Matrix in GFAAS

氯化钐的背景吸收在研究波长范围内呈单峰,其背景吸收来源于SmCl_2的分子蒸气和氯气;而硝酸钐的背景吸收在研究的波长内呈双峰,其背景吸收来源于NO和Sm_2O_3的分子蒸气、时间特性研究表明:氯化钐与硝酸钐背景吸收的时间分布有明显不同,可利用原子吸收信号与背景信号的时间分辨关系来减小甚至完全克服背景吸收干扰。温度特性研究表明:背景信号与加热速度和原子化温度有关。实验还表明:硝酸钐的背景吸收比氯化钐要小得多,因此把样品转变为硝酸盐,可大幅度地减小背景吸收的影响。

The nature and source of the background absorption of samarium matrix and the method for elimination of the background were studied. The background absorption of SmCl_3 matrix arises mainly from the absorption of SmCl_3 vapour. The background of Sm(NO_3)_3 matrix has been shown to be a double-peak in the interesting wave length range,coming from the absorption of decomposed-product NO and its oxides. The background absorption of Sm(NO_3)_3 is much smaller than that ot SmCl_2. (?)herefore, it is best to transfer samples to be analyseed into samarium nitrate for decreasing backgrond absorption.