Methyl chloroacetate as an extraction solvent for coupling liquid-liquid semimicroextraction with micellar electrokinetic chromatography through on-capillary decomposition for the separation of neutral compounds with concentration enhancement

This paper reports the use of methyl chloroacetate (MCA) as an extraction solvent for coupling liquid-liquid semimicroextraction (LLsME) with micellar electrokinetic chromatography (MEKC) through on-capillary decomposition for the separation of neutral compounds with concentration enhancement. Alkylphenones of C-8, C-10 and C-11 were chosen as modeling compounds. Aqueous samples of the alkylphenones were extracted by LLsME into methyl chloroacetate. The organic phase, after being separated from the aqueous phase, was directly subjected to separation by MEKC. The detection limits (S/N >= 3) were 0.05, 0.05 and 0.1 mg/L for butyrophenone, valerophenone and acetophenone in water, respectively, and the concentration factors of the extraction were in a range of 63 to 151-fold in terms of peak area for the three alkylphenones. Linearity and reproducibility of the method were also evaluated. Extraction and separation of a wastewater sample from a dye factory were included to demonstrate application potential of the method developed. The method developed has no requirement on any special experimental apparatuses other than a basic CE setup and is time saving and easy to operate. Therefore, it would be readily acceptable for routine analysis, especially for environmental water samples. (c) 2007 Elsevier B.V. All rights reserved.