Determination of PAEs by Integrative Coupling Method of Headspace in-Tube Microextraction and Reverse-Flow Micellar Electrokinetic Capillary Chromatography

An integrative coupling approach of headspace in-tube microextraction (HS-ITME) and reverse-flow micellar electrokinetic capillary chromatography (RF-MECC) was proposed for determination of phthalic acid esters (PAEs). In the novel method, by placing a capillary filled with background electrolyte (BGE) of RF-MECC in the HS above the sample solution, the PAEs were extracted into the acceptor phase in the capillary. Then, the extracts were separated and determined by RF-MECC. The influence of some essential BGE components such as sodium dodecyl sulfate (SDS) and organic modifier concentrations were investigated. Extraction parameters were also systematically investigated, including the extraction temperature, extraction time, salt concentration, and volume of the sample solution. Under the optimized conditions, enrichment factors for three PAEs were 169, 2534, and 1526, respectively. The proposed method provided a good linearity, low limits of detection, and good repeatability (RSDs below 5.44%, n  = 5). This method was then utilized to analyze the three PAEs in tap water, seawater, and beverage samples. The results indicated that the developed method is an excellent alternative for the PAE routine analysis in the food field.