石墨炉原子吸收光谱中尿的背景吸收研究

The Study of the Background Absorption of Urine Sample in the Graphite Furuace Atomic Absorption Spectroscopy

许多简单基体在石墨炉原子吸收中的背景吸收已有报道，Allain等还研究了血浆等复杂基体的背景吸收，但至今尚未见尿背景吸收的报道。本文较详细地研究了尿背景吸收的来源、特点和消除方法。背景吸收波长特性和在石墨管内蒸发行为的研究表明，尿的背景吸收主要来自氯化钠，其次是氯化铵，其他组分的贡献很小，时间特性研究表明，背景吸收大小和背景吸收曲线输廓与原子化附段的加热方式和原子化温度有关，还研究了应用基体改进剂和其他减小背景吸收的方法。

The nature and source of the backgronnd absrption of the nrine sample and the method of eliminating the background were studied. The wavelength-dependent of urine backgronnd is quite similar to that obtained from sodium chloride. This shown that the baekground absorption of the nrine sample arises mainly from sodium ohloride. When general heaing mode is ued, the outline of the background absorption ourves and peak height are dependent on the atomization temperature. However, above dependence is not observed in the case of maximum power heating mode. The background interferences from urine can be decreased by the addition of nitric acid. The ohoice of appropriate signal recording time, ashing temperature and time, heating mode are also effective for this purpose.