Trace determination of triclosan and triclocarban in environmental water samples with ionic liquid dispersive liquid-phase microextraction prior to HPLC–ESI-MS–MS

Abstract

A novel and environmentally friendly microextraction method, termed ionic liquid dispersive liquid-phase microextraction (IL-DLPME), has been developed for rapid enrichment of triclosan and triclocarban before analysis by high-performance liquid phase chromatography-electrospray tandem mass spectrometry (HPLC-ESI-MS-MS). Instead of using toxic organic solvents, an ionic liquid was used as a green extraction solvent. This also avoided the instability of the suspending drop in single-drop liquid-phase microextraction, and the heating and cooling step in temperature-controlled ionic liquid dispersive liquid phase microextraction. Factors that may affect the enrichment efficiency, for example volume of ionic liquid, type and volume of dispersive solvent, pH, extraction time, and NaCl content were investigated in detail and optimized. Under optimum conditions, linearity of the method was observed over the range 0.2-12 microg L(-1) for triclocarban and 1-60 microg L(-1) for triclosan with correlation coefficients ranging from 0.9980 to 0.9990, respectively. The sensitivity of the proposed method was found to be excellent, with limits of detection in the range 0.040-0.58 microg L(-1) and precision in the range 7.0-8.8% (RSD, n = 5). This method has been successfully used to analyze real environmental water samples and satisfactory results were achieved. Average recoveries of spiked compounds were in the range 70.0-103.5%. All these results indicated that the developed method would be a green method for rapid determination of triclosan and triclocarban at trace levels in environmental water samples.