石墨炉原子吸收法测定矿石中痕量铷和铯

Determination of Trace Rb and Cs by Furnace AAS

铷、铯属碱金属元素,其电离电位很低(Cs 3.983 eV、Rb 4.676 eV),常用火焰原子吸收(或发射)法测定。该法只适用于测定常量铷、铯。对痕量铷、铯多用X—荧光光谱法或中子活化法测定,很少有人用石墨炉原子吸收法。

A sensitive,simple and rapid method of direct derermination of trace ru-bidum and caesium in rocks by furnace atomic absorption spectrophotometry was described.Interfering effects of 39 diverse ions were investigated.Appropriate measures were taken to eliminate interferences from Fe(Ⅲ)and K.The mixed solution of K and Na sulphates were used as a matrix modifier to suppress the ionization of Cs.The characteristic mass of Rb and Cs was 7.9×10^(-12) g and 2.1×10^(-11) g,the detection limits was 0.054 ppm and 0.061 ppm and the RSD(n=ll)was 1.96%and 1.83%,respectively.