Abstract：Abstract: The colour reactions of the new chromogenic reagent 2.4-dichloro-6-bromo fluorophosphonazo with rare earth elements (RE) under microwave catalysis have been studied.In the medium of nitric acid and a small amount of pyridine, the chromogenic reagent reacts with separate rare earth elements and forms blue complexes, after being heated and catalyzed via microwave water-bath at 40℃ for 8 minutes.The molar ratios of typical rare earth elements lanthanum, cerium to reagent are both 1︰3. The maximum absorption wavelength of separate rare earth complex lies at 632～636 nm. Test wavelength is 634 nm. The molar absorptivity is close to each other with ε being 0.89~1.15×105 L?mol-1?cm-1. Test is conducted on different proportion of mixed rere earths, the result of which shows the proportion of La,Ce,Y has little influence on the measurements of total RE. With the solution of 4 mixed screening agents, the method can be applied to the determination of total RE in samples such as rock. The RSD is 2.0~2.4%, and the recovery of the method is 93~98%.
俞善辉 江瑜 柯佳鹏 戴聪聪. 2,4-二氯-6-溴偶氮氟膦与稀土的显色反应及其应用[J]. 冶金分析, 2012, 32(8): 20-24.
YU Shanhui, JIANG Yu, KE Jiapeng. Color reaction of 2.4-dichloro-6-bromo fluorophosphonazo with rare earths and its appplicaiton. , 2012, 32(8): 20-24.
［3］ Hong W G, Fa S H, Qing S Y. Investigation of properties of rare earth complexes with dibromo-p-methyl-methylsulfonazo by spectral correction technique［J］. Proceedings of the Indian Academy of Sciences-Chemical Sciences,2000,112(6)：573-578.
［4］ Jain V K, Handa A, Sait S S, et al. Agrawal preconcentration separation and trace determination of lanthanum(III), cerium(III), thorium and uranium on polymer supported o-vanillinsemicarbazone［J］. Anal.Chim. Acta, 2001, 429(2)： 237-246.
［5］ Zhai Q Z,Zhang X X. Color-fading spectrophotometric determination of cerium with DBC-arsenazo［J］. Journal of Rare Earths,2004,22(3)：440-442.
