Triton X-100存在下镉试剂分光光度法测定痕量铊(III)

Spectrophotometric Determination of Trace Amounts of Thallium with Cadion in the Presence of Triton X-100

分光光度法测定微量铊,目前主要以硷性染料作显色剂,采用萃取光度法[1],所使用的有机溶剂大都对人体有害.有关铊的水相直接光度测定的报道不多,而水相胶束增溶光度测定铊的报道则更少.

A highly sensitive spectrophotometric method for the determination of trace amounts of thallium(Ⅲ),using Cadion and Triton X-100 is described.It is the most sensitive method for the determination of thallium in aqueous solution.In buffered solution(NH4Cl-NH4OH)at pH11.0 and in the presence of a nonionic surfactant,Triton X-100,thallium(Ⅲ)and Cadion form a complex with the molar ratio of Tl:Cadion=1:5.The complex exhibits maximum absorption at 470nm with a molar absorptivity of 1.37x10~5L·mol-1·cm-1.Beer’s law obeyed in the concentration range of 0-1.2ppm of Tl.