Authors:Xiaobei Zheng, Feng Dong, Jing Yang, Xiaojiang Duan, Tingting Niu, Wangsuo Wu, and Jianjun Wang
This work reports the synthesis and preliminary biodistribution results of [131I]SIB-PEG4-CHC in tumor-bearing mice. The tributylstannyl precursor ATE-PEG4-CHC was synthesized by conjugation of ATE to amino pegylated colchicine NH2-PEG4-CHC. [131I]SIB-PEG4-CHC was radiosynthesized by electrophilic destannylation of the precursor with a yield of ~44%. The radiochemical purity
(RCP) appeared to be >95% by a Sep-Pak cartridge purification. [131I]SIB-PEG4-CHC was lipophilic and was stable at room temperature. Biodistribution studies in tumor-bearing mice showed that [131I]SIB-PEG4-CHC cleared from background rapidly, and didn’t deiodinate in vivo. However, the poor tumor localization excluded it from
further investigations as a tumor-targeted radiopharmaceuticals.
Sorption of U(VI) from aqueous solution to decarbonated calcareous soil (DCS) was studied under ambient conditions using batch
technique. Soil samples were characterized by XRD, FT-IR and SEM in detail and the effects of pH, solid-to-liquid ratio (m/V), temperature, contact time, fulvic acid (FA), CO2 and carbonates on U(VI) sorption to calcareous soil were also studied in detail using batch technique. The results from experimental
techniques showed that sorption of U(VI) on DCS was significantly influenced by pH values of the aqueous phase, indicating
a formation of inner-sphere complexes at solid–liquid interface, and increased with increasing temperature, suggesting the
sorption process was endothermic and spontaneous. Compared to Freundlich model, sorption of U(VI) to DCS was simulated better
with Langmuir model. The sorption equilibrium could be quickly achieved within 5 h, and sorption results fitted pseudo-second-order
model well. The presence of FA in sorption system enhanced U(VI) sorption at low pH and reduced U(VI) sorption at high pH
values. In absence of FA, the sorption of U(VI) onto DCS was an irreversible process, while the presence of FA reinforced
the U(VI) desorption process reversible. The presence of CO2 decreased U(VI) sorption largely at pH >8, which might due to a weakly adsorbable formation of Ca2UO2(CO3)3 complex in aqueous phase.