2-(2-喹啉偶氮)-5-二甲氨基苯酚固相萃取光度法测定铀的研究

Study on Solid Phase Extraction and Spectrophotometric Determination of Uranium in Water with 2-(2-Quinolylazo)-5-Dimthylaminophenol

合成了新试剂2(2喹啉偶氮)5二甲氨基苯酚(QADMAP),用红外光谱、核磁共振氢谱、质谱、可见吸收光谱和元素分析鉴定了其结构。研究了QADMAP与铀的显色反应,在pH7.8的三乙醇胺盐酸缓冲介质中,TritonX100和氟离子存在下,QADMAP与铀(Ⅵ)和氟离子反应生成1∶1∶1紫色三元稳定络合物,络合物的λmax=590nm,ε=1.05×105L·mol-1·cm-1,铀含量在0～20μg·10mL-1内符合比尔定律。环境水样中的铀用TBP萃淋树脂固相萃取柱分离和富集后用该方法测定,方法相对标准偏差在2.2%～3.6%之间,标准回收率在94%～105%。

A new chromogenic reagent 2-(2-quinolylazo)-5-Dimthylaminophenol (QADMAP) was synthesized, and its structure was verified by elemental analysis, infrared spectrum, (1)H nuclear magnetic resonance spectrum, mass spectrum and UV-spectrum. The color reaction of QADMAP with uranium was studied. In the presence of pH 7.8 buffer solution, when fluorin ion and Triton X-100 medium exist, QADMAP can react with uranium and fluorin to form a stable 1: 1: 1 stable complex [F(-) : QADMAP: U(VI) ]. The molar absorptivity is 1.05 X 10(5) L center dot mol(-1)center dot cm(-1) at 590 nm. Beer's law is obeyed in range of 0-20 mu g/mL. The uranium in samples can be enriched and separated by solid phase extraction with TBP resin cartridge. This method is applied to the determination of uranium in water sample. The relative standard deviations are 2.2% - 3.6%. and the recoveries are 94% - 105%.