Oszwałdowski S, Połeć K, Jarosz M
Department of Analytical Chemistry, Faculty of Chemistry, Warsaw University of Technology, ul. Noakowskiego 3, 00-664 Warsaw, Poland.
Talanta. 2000 Apr 3;51(4):817-24.
Optimum conditions for the reversed-phase liquid chromatographic separation of uranium as U(VI)-F(-)-(5-Br-PADAP) [5-Br-PADAP is 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol] ternary complex on the end-capped C18 column were evaluated. The developed sensitive, selective and versatile method allows to determine uranium in the wide concentration range 0.2-120.0 mug ml(-1) (detection limit, DL, is 0.15 mug ml(-1) for 20 mul loop). Solvent mixture, acetonitrile+water (65+35, v/v) containing fluoride in concentration 3x10(-3) mol l(-1) (pH 5.5) was used as eluent. Double action of fluoride present in eluent - as stabilising agent of the ternary system and modifier of the stationary phase was evaluated. In order to prove appearance of the modifying effect of fluoride on the stationary phase the new chromatographic probe - system Zr(IV)-(5-Br-PADAP)/Zr(IV)-F(-)-(5-Br-PADAP) was introduced as a tool for the detection of F(-) presence on the surface.
评估了在封端C18柱上反相液相色谱分离铀（以U(VI)-F(-)-(5-溴-2-吡啶偶氮)-5-二乙氨基苯酚[5-溴-2-吡啶偶氮-5-二乙氨基苯酚]三元配合物形式存在）的最佳条件。所建立的灵敏、选择性好且通用的方法能够在0.2 - 120.0 μg ml⁻¹的宽浓度范围内测定铀（对于20 μl定量环，检测限DL为0.15 μg ml⁻¹）。使用乙腈 + 水（65 + 35，v/v）的混合溶剂，其中含有浓度为3×10⁻³ mol l⁻¹的氟化物（pH 5.5）作为洗脱剂。评估了洗脱剂中氟化物的双重作用——作为三元体系的稳定剂和固定相的改性剂。为了证明氟化物对固定相的改性作用的存在，引入了新的色谱探针体系Zr(IV)-(5-溴-2-吡啶偶氮)-5-二乙氨基苯酚/Zr(IV)-F(-)-(5-溴-2-吡啶偶氮)-5-二乙氨基苯酚作为检测表面是否存在F(-)的工具。
