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.
ABSTRACT 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 > or = 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.
- [show abstract] [hide abstract]
ABSTRACT: Recent advances in CE and CEC separation, detection and sample preparation/preconcentration methodologies, for the determination of a variety of compounds having current or potential environmental relevance, have been overviewed. The reviewed literature has illustrated the wide range of CE applications available, indicating a continuing interest in CE and CEC in the environmental field. New developments in chip-based CE systems are also discussed.Electrophoresis 02/2008; 29(1):310-23. · 3.26 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: This article reviews the latest methodological and instrumental improvements for enhancing sensitivity and resolution in MEKC-based determinations. On-line sample concentration (stacking, sweeping and combination of two protocols) and other on-capillary approaches such as in-capillary derivatization and the coupling of flow-injection systems with MEKC are the most relevant methodological approaches discussed for improving sensitivity. At the same time, changes in the BGE through the use of organic modifiers, ionic liquids, cations, CDs, non-ionic and zwitterionic surfactants, mixed micelles, vesicles and carbon nanostructures as well as 2-D CE and chemometric techniques for enhancing resolution are also considered in detail. Two instrumental approaches such as MS and LIF are also discussed, covering the proposals for overcoming the difficulties arising from the direct coupling of MEKC with MS and the excellent detection sensitivity achieved by LIF using the typical argon-ion laser and recent growth in the use of diode lasers as excitation sources. Some thoughts on potential future directions are also expressed.Electrophoresis 01/2009; 30(1):50-64. · 3.26 Impact Factor