Choi Young-Woo, Minoura Norihiko, Moon Seung-Hyeon
Research Center of Advanced Bionics, National Institute of Advanced Industrial Science and Technology, Central 4, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8562, Japan.
Talanta. 2005 Jun 15;66(5):1254-63. doi: 10.1016/j.talanta.2005.01.040. Epub 2005 Feb 17.
For the determination of Cr(VI) concentrations with a potentiometric ion-selective electrode (ISE), ionophore-immobilized membranes were prepared by ultraviolet (UV)-induced graft polymerization followed by chemical treatment. Novel ionophores comprising various amine structures were immobilized onto poly(vinyl chloride) (PVC) matrixes, and these were examined to determine Cr(VI) selectively. Of the three ionophores examined in this study, the membranes with N,N,N,N-tetrakis(3-aminopropyl)-1,4-butanediamine (DABAm4) exhibited the highest Cr(VI) ion selectivity in both extraction and potentiometry experiments. The plasticizer in the membrane was optimized as 1.0ml o-nitrophenyl octyl ether (NPOE)/g PVC to form diffusible channels. The potentiometric studies revealed that the performance of DABAm4-immobilized PVC was equivalent to that of mobile ionophores in supported liquid membranes (SLMs). A reproducible response of Cr(VI) was attained within a response time of 1s in the range of 2.16x10(-6) to 0.1M, using the membrane prepared in this study. The selectivity for the Cr(VI) ion against the other interfering ions was compared reasonably between a solvent extraction and potentiometry. The long-term response of the Cr(VI) ISE showed slight deterioration over a continuous operation for 6 months, while the detection limit slightly decreased due to the leaching-out of the plasticizer. The ISE along with the DABAm4 immobilized membrane showed a higher Cr(VI) ion selectivity and more stable response under long-term usage than ISEs with typical SLMs.
为了用电位离子选择性电极（ISE）测定六价铬（Cr(VI)）的浓度，通过紫外线（UV）诱导接枝聚合然后进行化学处理制备了固定有离子载体的膜。将包含各种胺结构的新型离子载体固定在聚氯乙烯（PVC）基质上，并对其进行检测以选择性地测定Cr(VI)。在本研究中检测的三种离子载体中，含有N,N,N,N-四（3-氨丙基）-1,4-丁二胺（DABAm4）的膜在萃取和电位测定实验中均表现出最高的Cr(VI)离子选择性。将膜中的增塑剂优化为1.0ml邻硝基苯基辛基醚（NPOE）/g PVC，以形成可扩散通道。电位测定研究表明，固定有DABAm4的PVC的性能与支撑液膜（SLM）中流动离子载体的性能相当。使用本研究制备的膜，在2.16x10(-6)至0.1M的范围内，在1s的响应时间内可获得Cr(VI)的可重现响应。在溶剂萃取和电位测定之间合理比较了Cr(VI)离子对其他干扰离子的选择性。Cr(VI) ISE的长期响应在连续运行6个月后显示出轻微劣化，而检测限由于增塑剂的浸出而略有降低。与典型的SLM的ISE相比，带有固定有DABAm4的膜的ISE在长期使用下表现出更高的Cr(VI)离子选择性和更稳定的响应。
