衬钽管石墨炉原子吸收光谱测定锡时基体改进剂和保护气氛的研究

STUDIES ON THE MATRIX MODIFIER AND THE PURGE GAS IN THE DETERMINATION OF TIN BY TANTALUM FOIL-LINED GFAAS

本文提出用Ar-5%H_2作保护气氛和铜作基体改进剂的衬钽管石墨炉原子吸收光谱测定锡的方法。衬钽管的测定灵敏度是热解涂层石墨管的六倍左右。本法抗干扰能力强,测定精度(R.S.D.)小于2%。H_2保护了衬钽管,测定重现性好,衬钽管使用寿命可达650次左右。本法不经预分离直接测定蕃茄、蘑菇罐头及河流底泥样品中的锡,结果与其它方法相吻合。

A method is presented for the determination of tin by tantalum foil-lined graphite furnace atomic absorption spectrometry with argon-hydrogen as the purge gas and Cu as a matrix modifier. The tantalum foil-lined graphite tube gave an enhanced sensitivity which was about six-fold that of the pyrolytic graphite tube. This method eliminated effectively many interferences. The R.S.D was less than 2%, a little amount of H_2 added to Ar kept the tantalum foil-lined tube in good analytical reproducibility. The life of a tantalum foil-lined tube reached about 650 cycles, This method was applied to directly determinate tin in the canned tomoto, mushroom and the river sediments without re-separation. The results obtained were well agreement with those of other methods.