Determination of Phenol and Carvacrol in Honey Samples Using Dispersive Liquid-Liquid Microextraction and Experimental Design for Optimization

A very simple, rapid and sensitive dispersive liquid-liquid microextraction (DLLME) followed by gas chromatography and flame ionization detection (GC-FID) was developed for the determination of phenol and carvacrol in honey samples. A mixture of 100 mu l dichloromethane (extraction solvent) and 0.5 ml acetonitrile (disperser solvent) was rapidly injected into sample solution. Thereby a cloudy solution was formed. After centrifuging, the fine droplets of extraction solvent were sedimented in the bottom of the conical test tube. Sedimented phase (0.6 mu l) was injected into the GC-FID system. Experimental parameters which control the performance of DLLME, such as type and volumes of extraction and disperser solvents, pH, salt effect and extraction time were investigated. Under optimum conditions obtained by the response surface methodology, the method was found to be linear in the range of 10-200 mg l(-1). The limits of detection for phenol and carvacrol were 4.15 and 3.9, respectively, and the extraction recovery ranged from 67-97.3%.