2-(2-喹啉偶氮)-1,3-二羟基苯固相萃取光度法测定水中铀

Study on Solid Phase Extraction and Spectrophotometric Determination of Uranium in Water Samples with 2-(2-Quinolinylazo)-1,3-Dihydroxidebenzene

研究了2-(2-喹啉偶氮)-1,3-二羟基苯(QADHB)与铀的显色反应,在TritonX-100和F-存在下,pH7.8的三乙醇胺-HCl缓冲介质中,QADHB与U(Ⅵ)、F-反应生成1∶1∶1紫色三元稳定配合物,配合物的λmax=560nm,ε=7.41×104L·mol-1·cm-1。铀含量在0～2000μg/L内符合比尔定律。环境水样中的铀经磷酸三丁脂萃淋树脂固相萃取柱分离和富集后测定。方法已用于实际样品的测定,分析结果与国标(5-Br-PADAP)法一致,相对标准偏差(n=5)为2.4%～4.7%,回收率为96%～105%。

The color reaction of 2-(2-quinolinylazo)-1,3-dihydroxidebenzene (QADHB) with uranium was studied. In the presence of TritonX-100 and F^(-) and in triethanolamine-HCl buffer solution (pH=7.8), QADHB reacts with uranium and F^(-) to form a 1∶1∶1 stable complex (F^(-)∶QADMAB∶U(Ⅵ)). The molar absorptivity is 7.41×10^(4) L·mol^(-1)·cm^(-1 )at 560 nm. Beer′s law is obeyed in range of 0～2 000 μg/L for uranium. The uranium in samples can be enriched and separated by solid phase extraction with TBP resin cartridge. This method has been applied to the determination of uranium in water samples. The results are satisfactory with recovery of 96%～105% and precision of 2.4%～4.7% RSD(n=5).