it was found that methylene blue in 1,2-dichloroethane fluoresces at 682nm and the presence of 〔TlCl4〕- greatly enhances the intensity and shifts the emission to 730nm. A method for the determination of Tl is proposed on the basis of the observation. The determination wavelengths are optimized at 468 nm/730nm (λcx/λcm),and 2 ml of dichloroethane is used for the extraction of Tl from 25 ml of 0.5mol/l HC1 in the presence of 8μg/ml methylene blue. 0.05-5ppm of T1(Ⅲ) can be determined in the organic phase. Pro...