Asiabi Hamid, Yamini Yadollah, Seidi Shahram, Ghahramanifard Fazel
Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran, Iran.
Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran, Iran.
Anal Chim Acta. 2016 Mar 24;913:76-85. doi: 10.1016/j.aca.2016.01.060. Epub 2016 Feb 3.
In the present work, an automated on-line electrochemically controlled in-tube solid-phase microextraction (EC-in-tube SPME) coupled with HPLC-UV was developed for the selective extraction and preconcentration of indomethacin as a model analyte in biological samples. Applying an electrical potential can improve the extraction efficiency and provide more convenient manipulation of different properties of the extraction system including selectivity, clean-up, rate, and efficiency. For more enhancement of the selectivity and applicability of this method, a novel molecularly imprinted polymer coated tube was prepared and applied for extraction of indomethacin. For this purpose, nanostructured copolymer coating consisting of polypyrrole doped with ethylene glycol dimethacrylate was prepared on the inner surface of a stainless-steel tube by electrochemical synthesis. The characteristics and application of the tubes were investigated. Electron microscopy provided a cross linked porous surface and the average thickness of the MIP coating was 45 μm. Compared with the non-imprinted polymer coated tubes, the special selectivity for indomethacin was discovered with the molecularly imprinted coated tube. Moreover, stable and reproducible responses were obtained without being considerably influenced by interferences commonly existing in biological samples. Under the optimal conditions, the limits of detection were in the range of 0.07-2.0 μg L(-1) in different matrices. This method showed good linearity for indomethacin in the range of 0.1-200 μg L(-1), with coefficients of determination better than 0.996. The inter- and intra-assay precisions (RSD%, n = 3) were respectively in the range of 3.5-8.4% and 2.3-7.6% at three concentration levels of 7, 70 and 150 μg L(-1). The results showed that the proposed method can be successfully applied for selective analysis of indomethacin in biological samples.
在本研究中，开发了一种自动在线电化学控制管内固相微萃取（EC-管内SPME）与HPLC-UV联用的方法，用于生物样品中作为模型分析物的吲哚美辛的选择性萃取和预富集。施加电势可以提高萃取效率，并为萃取系统不同性质（包括选择性、净化、速率和效率）的操作提供更便利的条件。为了进一步提高该方法的选择性和适用性，制备了一种新型分子印迹聚合物涂层管并用于吲哚美辛的萃取。为此，通过电化学合成在不锈钢管内表面制备了由掺杂乙二醇二甲基丙烯酸酯的聚吡咯组成的纳米结构共聚物涂层。研究了该管的特性和应用。电子显微镜显示其表面为交联多孔结构，分子印迹聚合物涂层的平均厚度为45μm。与非印迹聚合物涂层管相比，分子印迹涂层管对吲哚美辛具有特殊的选择性。此外，获得了稳定且可重复的响应，且不受生物样品中常见干扰物的显著影响。在最佳条件下，不同基质中的检测限在0.07 - 2.0μg L⁻¹范围内。该方法对吲哚美辛在0.1 - 200μg L⁻¹范围内具有良好的线性，测定系数优于0.996。在7、70和150μg L⁻¹三个浓度水平下，批间和批内精密度（RSD%，n = 3）分别在3.5 - 8.4%和2.3 - 7.6%范围内。结果表明，所提出的方法可成功应用于生物样品中吲哚美辛的选择性分析。
