Department of Chemistry and the Key Laboratory of Analytical Sciences of the Ministry of Education, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China.
J Chromatogr A. 2010 Mar 12;1217(11):1735-41. doi: 10.1016/j.chroma.2010.01.034. Epub 2010 Jan 20.
In this paper, we proposed an approach using a multi-walled carbon nanotubes (MWCNTs)/Nafion composite coating as a working electrode for the electrochemically enhanced solid-phase microextraction (EE-SPME) of charged compounds. Suitable negative and positive potentials were applied to enhance the extraction of cationic (protonated amines) and anionic compounds (deprotonated carboxylic acids) in aqueous solutions, respectively. Compared to the direct SPME mode (DI-SPME) (without applying potential), the EE-SPME presented more effective and selective extraction of charged analytes primarily via electrophoresis and complementary charge interaction. The experimental parameters relating to extraction efficiency of the EE-SPME such as applied potentials, extraction time, ionic strength, sample pH were studied and optimized. The linear dynamic range of developed EE-SPME-GC for the selected amines spanned three orders of magnitude (0.005-1mugmL(-1)) with R(2) larger than 0.9933, and the limits of detection were in the range of 0.048-0.070ngmL(-1). All of these characteristics demonstrate that the proposed MWCNTs/Nafion EE-SPME is an efficient, flexible and versatile sampling and extraction tool which is ideally suited for use with chromatographic methods.
本文提出了一种使用多壁碳纳米管（MWCNTs）/Nafion 复合涂层作为工作电极的方法，用于电化学增强固相微萃取（EE-SPME）带电化合物。分别施加合适的正、负电位以增强水溶液中阳离子（质子化胺）和阴离子（去质子羧酸）的萃取。与直接固相微萃取模式（DI-SPME）（不施加电位）相比，EE-SPME 通过电泳和互补电荷相互作用更有效地选择性萃取带电分析物。研究并优化了与 EE-SPME 萃取效率相关的实验参数，如施加的电位、萃取时间、离子强度、样品 pH 值。开发的 EE-SPME-GC 对所选胺的线性动态范围跨越三个数量级（0.005-1μgmL（-1）），R（2）大于 0.9933，检测限范围为 0.048-0.070ngmL（-1）。所有这些特征表明，所提出的 MWCNTs/Nafion EE-SPME 是一种高效、灵活且多功能的采样和萃取工具，非常适合与色谱方法结合使用。
