Sensitivity Enhancement in Uranium Determination by UV-Visible Spectroscopy Using Ion Imprinted Polymer

There is need to determination of uranium concentration at ppb level in environmental matrices. Due to low sensitivity of FAAS, UV-Visible Spectroscopy is generally used as measurement technique. In this study, ion-imprinted polymers (IIP) were prepared for uranyl ion (imprint ion) by formation of ternary (salicylaldoxime and 4-vinylpyridine) complex in 2-methoxy ethanol (porogen) following copolymerization with methacrylic acid (MAA) as a functional monomer and ethylene glycol dimethacrylate (EGDMA) as crosslinking monomer using 2,2-azobisisobutyronitrile as initiator. The synthesized polymers were characterized by FT-IR and TGA analysis. Arsenazo Ⅲ in 3 M HClO₄ was used as complexing agent in the measurement step. The optimal pH for preconcentration was found to be between 3.5～6.5 values. The developed method was applied to uranium (Ⅵ) determination in natural water samples.     

中国地体构造研究进展综述

地体构造理论被应用于中国地质的具体实践已经１５年并取得了丰硕的成果,主要表现在：１．中国境内地体构造的划分,２．地体构造理论上的创新,包括地体定义的完善;板块、微板块、地体、板惩、覆体五者之间的理论甄别,地体的古板块单元重建和古地体古大洋研究;地体拼贴增生和裂解离散的形式和过程,地体运动形成的沉积盆地和能源矿产;３．方法学上的进展,主要有古地磁喾综合地球物理学、微古生物及其对含放射虫硅质岩的新认识