This paper is engaged in the study of valence status transformation between Tl(Ⅰ) and Tl(Ⅲ) in UV-H2O2 system.For this purpose,we have tried a simplified,quick-effective chelex-100 resin-column separating technique and adopted the graphite furnace atomic absorption spectrometer to determining Tl(Ⅰ) and Tl(Ⅲ) in the UV-H2O2 reaction.For this purpose,we have done experiments by pumping a water sample with its pH of 110 by using a small plug of the Na-form of chelex,that is,a 100 resin at a flow rate of 0.5-10...