Department of Chemistry, Federal University of Santa Catarina, Florianopolis, SC, Brazil.
J Chromatogr A. 2011 Jul 15;1218(28):4586-91. doi: 10.1016/j.chroma.2011.04.084. Epub 2011 May 13.
The aim of this study was to develop a fast CE separation method by using multiple short-end injections in a capillary coated with quaternary ammonium chitosan (HACC), in order to determine the iodide content of pharmaceutical formulations. The BGE was composed of 20 mM tris(hydroxymethyl)aminomethane and 11 mM hydrochloric acid, at pH 8. The internal standard used was thiocyanate. Separations were performed in a fused silica capillary (32 cm total length, 8.5 cm effective length and 50 μm i.d.) coated with HACC and direct UV detection at 220 nm. EOF was modified by flushing the capillary with polymeric solution, resulting in a semi-permanent coating of controlled and stable EOF. The EOF was anodic at pH 8. Different strategies, using single and multiple injection short-end configurations, were studied to develop a CE method that resulted in a maximum number of iodide samples analyzed per hour: one plug and flush (Sflush) 35 samples/h, one plug without flush (SWflush) 76 samples/h, four plugs and flush (Mflush) 61 samples/h, and four plugs without flush (MWflush) 80 samples/h. Using the multiple injection configuration, it was possible to inject up to four plugs using spacer electrolytes with good separation efficiency and selectivity. The voltage application time needed to separate the eight peaks (iodide and thiocyanate) with MWflush was only 12s. The method was validated and samples were analyzed using MWflush. Good linearity (R(2)>0.999); a limit of detection 0.4 mg L(-1); intermediate precision better than 3.8% (peak area) and recovery in the range of 99-102% were obtained.
本研究旨在开发一种快速 CE 分离方法，通过在涂有季铵化壳聚糖（HACC）的毛细管中进行多次短端进样，以测定药物制剂中的碘化物含量。BGE 由 20 mM 三羟甲基氨基甲烷和 11 mM 盐酸组成，pH 值为 8。所用的内标物为硫氰酸盐。分离在涂有 HACC 的熔融石英毛细管（总长度 32 cm，有效长度 8.5 cm，内径 50 μm）中进行，并在 220nm 处进行直接紫外检测。通过用聚合物溶液冲洗毛细管来修饰 EOF，从而实现对 EOF 的半永久性控制和稳定涂层。在 pH 8 时，EOF 为阳极。研究了使用单端和多端进样短端配置的不同策略，以开发一种 CE 方法，该方法可在每小时内分析最大数量的碘化物样品：一次进样冲洗（Sflush）35 个样品/小时，一次进样不冲洗（SWflush）76 个样品/小时，四次进样冲洗（Mflush）61 个样品/小时，四次进样不冲洗（MWflush）80 个样品/小时。使用多端进样配置，可以使用具有良好分离效率和选择性的间隔电解质注入多达四个插件。使用 MWflush 分离八个峰（碘化物和硫氰酸盐）所需的电压施加时间仅为 12s。该方法经过验证，并使用 MWflush 对样品进行了分析。得到了良好的线性（R(2)>0.999）；检测限为 0.4mg L(-1)；中间精密度优于 3.8%（峰面积），回收率在 99-102%范围内。
