Dawod Mohamed, Breadmore Michael C, Guijt Rosanne M, Haddad Paul R
Australian Centre for Research on Separation Science, School of Chemistry, University of Tasmania, Hobart, Tasmania, Australia.
J Chromatogr A. 2009 Apr 10;1216(15):3380-6. doi: 10.1016/j.chroma.2009.02.014. Epub 2009 Feb 11.
Electrokinetic supercharging (EKS) has been used in the last few years as a powerful tool for separation and on-line preconcentration of different types of analytes. We have developed a valuable modification for EKS system, namely counter-flow EKS (CF-EKS) and applied it for the separation and on-line preconcentration of seven non-steroidal anti-inflammatory drugs (NSAIDs) in water samples. In CF-EKS, a hydrodynamic counter-flow is applied during electrokinetic injection of the analytes within the EKS system. This counter-flow minimises the introduction of the sample matrix into the capillary, allowing longer injections to be performed. Careful choice of the optimum counter-flow as well as the optimum injection voltage allowed the sensitivity to be enhanced by 11,800-fold, giving limits of detection (LODs) of 10.7-47.0 ng/L for the selected NSAIDs. The developed method was validated and then applied for the determination of the studied NSAIDs in drinking water as well as wastewater samples from Hobart city.
在过去几年中，电动增压（EKS）已成为一种用于分离和在线预富集不同类型分析物的强大工具。我们对EKS系统进行了一项有价值的改进，即逆流EKS（CF-EKS），并将其应用于水样中七种非甾体抗炎药（NSAIDs）的分离和在线预富集。在CF-EKS中，在EKS系统内对分析物进行电动进样时施加流体动力逆流。这种逆流可最大限度地减少样品基质进入毛细管，从而能够进行更长时间的进样。仔细选择最佳逆流以及最佳进样电压可使灵敏度提高11800倍，所选NSAIDs的检测限（LOD）为10.7 - 47.0 ng/L。所开发的方法经过验证后，应用于霍巴特市饮用水以及废水样品中所研究的NSAIDs的测定。
