石墨炉原子吸收光谱法测定豆瓣酱中镉的研究

Determination of Cd in bean paste by graphite furnace atomic absorption spectrometry

用经干法处理后的豆瓣酱样品,分别以Mg(NO3)2、La(NO3)3、PdCl2、NH4H2PO4、NH4NO3、酒石酸、柠檬酸、Vc、草酸作为基体改进剂,对石墨炉原子吸收光谱法测定豆瓣酱镉含量过程中,这9种基体改进剂的加入量、灰化温度、原子化温度及作用机理进行了探讨。实验表明,基体改进剂的使用有效降低了背景吸收,提高了信背比,有效消除了食盐的基体干扰。

Samples of bean paste were digested by dry method,and Mg（NO3）2,La（NO3）3,PdCl2,NH4H2PO4,NH4NO3,tartaric acid,citric acid,Vc and oxalic acid were used as matrix modifier in the determination of cadmium by GFAAS.The additive amount,charring temperature,atomization temperature and its mechanism were studied.It was concluded that the lower background absorption and the higher signal to background ratio can be gained when the matrix modifiers were used.And matrix modifiers can eliminate salt matrix interference effectively.