Hu W, Hasebe K, Tanaka K, Haddad P R
Division of Chemistry, Graduate School of Science, Hokkaido University, Sapporo, Japan.
J Chromatogr A. 1999 Jul 30;850(1-2):161-6. doi: 10.1016/s0021-9673(99)00436-7.
A new type of zwitterionic surfactant, N-{2-[acetyl(3-sulfopropyl)amino]ethyl}-N,N-dimethyldodecanaminium hydroxide (ammonium sulfobetaine-1), with a greater distance between the two charged groups, was used as the stationary phase for electrostatic ion chromatography (EIC) of polarizable anions (e.g., thiocyanate, iodide and nitrate) in saline water samples. The targeted species (polarizable anions) were baseline separated using this type of zwitterionic surfactant as the stationary phase, but the highly polarizable species (iodide and thiocyanate) were eluted faster (compared with the results obtained using N-dodecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate, C12N3S, with a shorter distance between the two charged groups, as the stationary phase). In other words, the extent of binding of the highly polarizable anion (iodide and thiocyanate) was found to be smaller when using ammonium sulfobetaine-1 as the stationary phase. This provides a rapid but effective method for the analysis of highly polarizable anions in saline water samples. The results for the successful detection of iodide in seawater demonstrates the usefulness of this new type of zwitterionic surfactants for EIC.
一种新型两性离子表面活性剂，N-{2-[乙酰基(3-磺丙基)氨基]乙基}-N,N-二甲基十二烷基氢氧化铵（磺基甜菜碱-1），其两个带电基团之间的距离更大，被用作固定相，用于对盐水样品中的可极化阴离子（如硫氰酸盐、碘化物和硝酸盐）进行静电离子色谱（EIC）分析。使用这种两性离子表面活性剂作为固定相可实现目标物质（可极化阴离子）的基线分离，但高极化性物质（碘化物和硫氰酸盐）的洗脱速度更快（与使用N-十二烷基-N,N-二甲基-3-铵基-1-丙烷磺酸盐（C12N3S，两个带电基团之间的距离较短）作为固定相时获得的结果相比）。换句话说，当使用磺基甜菜碱-1作为固定相时，发现高极化性阴离子（碘化物和硫氰酸盐）的结合程度较小。这为分析盐水样品中的高极化性阴离子提供了一种快速但有效的方法。海水中碘化物成功检测的结果证明了这种新型两性离子表面活性剂用于EIC的实用性。
