萃取分离-石墨炉原子吸收光谱法测定盐卤中痕量铯的研究

采用墨炉原子吸收光谱法（ＧＦＡＡＳ）研究盐卤中铯原子化行为和机理，建立了热解石墨管、ＫＮＯ３－ＮＨ４ＮＯ３基体改进剂、１８－冠－６、溴百里香酚蓝、氯仿萃取分离－ＧＦＡＡＳ测定盐卤中铯的方法。用于测定盐卤中痕量铯，特征质量１．４×１０－１０ｇ／０．００４４Ａ；加标回收率８９％～１０５％；相对标准偏差４．１３％。

Study on the Determination of Trace Caesium in Bittern by Extraction Separation Graphite Furnace Atomic Absorption Spectrometry

The atomizatiom behavior of Cs in bittern and the mechanism were studied by graphite furnace atomic absorption spectrometry. Interferences of inorganic acid from the bittern on absorption signal of Cs were examined. It is shown that there are gaseous interferences and molecular absorption interferences and ionization interferences with regard to the interference of chlorides on absorption signal of Cs. The effects of 3 crown ethers, 5 big-anion reagents and chlorides on extractability Cs have been compared. A extraction separation GFAAS method for determining Cs in bittern has been established by pyrolytic graphite tube, KNO3-NH4NO3 matrix modifier and 18-C-6, bromothymol blue, chloroform extraction separation. The method exhibits high sensitivity and selectivity, it has been used for the determination of trace Cs in bittern. The characteristic mass is 1.4 x 10(-10) g/0.004 4 A. The adding recovery is 89%-105% and the relative standard deviation is 4.13% (n = 13).