Department of Chemistry, The University of Western Ontario, London, Ontario, Canada.
Anal Chem. 2012 Jul 17;84(14):6143-9. doi: 10.1021/ac301051e. Epub 2012 Jul 3.
The electrochemical extraction of rubidium at micro water|1,2-dichloroethane (w|DCE) and water|room-temperature ionic liquid (w|RTIL) interfaces housed at the tip of a 25-μm capillary using octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) in the TRans Uranic EXtraction (TRUEX) process, was examined. Rubidium is of great interest in a modern spent nuclear fuel cycle as well as toward myocardial perfusion imaging utilizing (82)Sr/(82)Rb isotopic generators. The ligand-to-metal stoichiometry (n:1) and overall complexation constant (β) for interfacial complexation reactions induced by an applied potential were determined by the interfacial electrochemistry. One stoichiometry, n = 2, was observed at the w|DCE interface with β = 3.3 × 10(4). In the w|RTIL system, two rubidium salt solutions were employed: RbNO(3) and RbNO(3) plus Rb(2)SO(4). The former demonstrated a stoichiometry of n = 2 and β = 2.4 × 10(6), while the latter showed n = 4 and β = 3.3 × 10(12). These stoichiometries of the reaction were confirmed by electrospray ionization mass spectrometry, using an emulsion generated by shaking water and DCE phases containing the dissolved metal and ligand, respectively. Both RbCMPO(+) and RbCMPO(2)(+) complexes were observed. The influence of ion pair interactions in this system will be discussed.
在 25-μm 毛细管口内，使用辛基（苯基）-N，N-二异丁基碳酰胺甲基膦酸氧化物（CMPO），在微水-1,2-二氯乙烷（w|DCE）和水-室温离子液体（w|RTIL）界面进行电化学提取铷。铷在现代乏核燃料循环以及利用（82）Sr/（82）Rb 同位素发生器进行心肌灌注成像方面具有重要意义。通过界面电化学确定了界面配位反应的配体-金属化学计量比（n：1）和整体配合常数（β），这些反应是由外加电势引起的。在 w|DCE 界面观察到一种化学计量比，n = 2，β = 3.3×10(4)。在 w|RTIL 体系中，使用了两种铷盐溶液：RbNO(3)和 RbNO(3)加 Rb(2)SO(4)。前者表现出 n = 2 和 β = 2.4×10(6)的化学计量比，而后者则显示出 n = 4 和 β = 3.3×10(12)的化学计量比。通过电喷雾电离质谱（ESI-MS）对反应的化学计量比进行了确认，方法是摇动分别含有溶解金属和配体的水相和 DCE 相，生成乳液。观察到 RbCMPO(+)和 RbCMPO(2)(+)配合物。将讨论该体系中离子对相互作用的影响。
