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Determination of malachite green in fish water samples by cloud‐point extraction coupled to cation‐selective exhaustive injection and sweeping‐MEKC
Author(s) -
Luo Xubiao,
Jiang Xin,
Tu Xinman,
Luo Shenglian,
Yan Liushui,
Chen Bo
Publication year - 2010
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.200900565
Subject(s) - malachite green , cloud point , chemistry , fish <actinopterygii> , extraction (chemistry) , chromatography , analytical chemistry (journal) , fishery , biology , organic chemistry , adsorption
Abstract We have employed a high‐sensitivity off‐line coupled with on‐line preconcentration method, cloud‐point extraction (CPE)/cation‐selective exhaustive injection (CSEI) and sweeping‐MEKC, for the analysis of malachite green. The variables that affect CPE were investigated. The optimal conditions were 250 g/L of Triton X‐100, 10% of Na 2 SO 4 (w/v), heat‐assisted at 60°C for 20 min. We monitored the effects of several of the CSEI‐sweeping‐MEKC parameters – including the type of BGE, the concentrations of SDS, the injection length of the high‐conductivity buffer, and the injection time of the sample – to optimize the separation process. The optimal BGE was 50 mM citric acid (pH 2.2) containing 100 mM SDS. In addition, electrokinetic injection of the sample at 15 kV for 800 s provided both high separation efficiency and enhanced sweeping sensitivity. The sensitivity enhancement for malachite green was 1.9×10 4 relative to CZE; the coefficients of determination exceeded 0.9928. The LOD, based on an S / N of 3:1, of CSEI‐sweeping‐MEKC was 0.87 ng/mL; in contrast, when using off‐line CPE/CSEI‐sweeping‐MEKC the sensitivity increased to 69.6 pg/mL. This proposed method was successfully applied to determine trace amounts of malachite green in fish water samples.