Surfactant-free Microemulsion Reinforced Hollow-Fiber Liquid-Phase Microextraction Combined with Micellar Electrokinetic Capillary Chromatography for Detection of Phthalic Acid Esters in Beverage and Urine

For the first time, the surfactant-free microemulsion reinforced hollow-fiber liquid-phase microextraction (SFME-HF-LPME) was developed for the determination of phthalic acid esters (PAEs) followed by field-enhanced sample injection with reverse migrating micelles (FESI-RMM) in capillary electrophoresis. An SFME composed of toluene, isopropanol, and water was used to reinforce HF. The prepared SFME-HF was applied to extract PAEs. After extraction, analytes were desorbed and analyzed by capillary electrophoresis. Several important parameters influencing the extraction efficiency of SFME-HF-LPME such as the type of extraction solvent, SFME component, extraction time, desorption condition, pH value, stirring rate, and salting-out effects were optimized. The proposed method provided a good linearity, low limits of detection, and good repeatability of the extractions. This method was then utilized to analyze trace PAEs in beverage and urine. The results indicated that the developed method is an excellent alternative for the PAEs routine analysis in the food and biological field.