石墨炉原子吸收中氯化镍和硝酸镍背景吸收来源和特点的研究

THE STUDIES OF THE BACKGROUND SOURCE AND CHARACTERS OF NICKEL CHLORIDE AND NITRATE IN THE GRAPHITE FURNACE ATOMIC ABSORPTION SPECTROMETRY

背景吸收波长特性的研究表明,氯化镍的背景吸收在某些波长呈双峰,第一个峰在190至420nm均存在明显的背景吸收,萁中以190和340nm为最大;第二个峰的峰高很小,且只在205、235、300、310、325和345nm附近出现。硝酸镍的背景吸收比氯化镍要小得多,在某些波长亦呈双蜂,第一个峰在190、205、215和225nm出现;第二个峰出现的波长与氯化镍的第二个峰完全相同。蒸发行为的研究表明,氯化镍的第一个背景吸收峰来自氯化镍的分子蒸气,硝酸镍的第一个背景吸收峰由一氧化氮所产生,它们的第二个吸收峰同是由氧化镍的蒸发所引起。温度特性的研究表明,氯化镍和硝酸镍背景吸收曲线的轮廓与原子化温度和原子化方式有关、背景吸收的峰高与灰化温度有关。时间特性的研究表明,对于某些元素可通过选择原子化阶段记录原子吸收信号的时间来减小甚至消除背景吸收干扰。

The results showed, There are two background peaks in some wavelengthes for NiCl_2. The first peak is high at 190 and 340 nm.The second peak appears at 205, 235, 300, 310, 325 and 345 nm and is lower than the first peak. The back ground of Ni(NO_3)_2 is much smaller than NiCl_2. There are two peaks in some wavelengthes, too. The first peak appears at 190,205,215 and 225 nm. Wavelengthes of the second peak of Ni(NO_3)_2 are as same as NiCl_2. The studies of vaporization behaviour of NiCl_2 and Ni(NO_3)_2 show the first background peak of NiCl_2 arises from vapour of NiCl_2. The first background peak of nitrate arises from NO. The second peaks of them arise from NiO. The background peak height, appearing time and outline are dependent on the atomization temperature and heating rate. The studies of the atomization time vs. Absorption curves show that the background interferences can be decreased even eliminated by the choice of an appropriate signal recording time under certain conditions.