Rapid screening of five phthalate esters from beverages by ultrasound-assisted surfactant-enhanced emulsification microextraction coupled with gas chromatography

A rapid ultrasound-assisted surfactant-enhanced emulsification microextraction (UASEME) method coupled with gas chromatography-flame ionization detection (GC-FID) is proposed for the rapid screening of five phthalate esters in bottled beverages. In the UASEME procedure, a nonionic surfactant (Triton X-100) was used as the emulsifier, without application of any organic dispersive solvents typically required in dispersive liquid-liquid microextraction. Triton X-100 as the emulsifier accelerated the formation of fine droplets from the extraction solvent in the sample solution under ultrasound radiation, thus combining the advantages of dispersive liquid-liquid microextraction (DLLME) and ultrasound-assisted emulsification microextraction (UAEME). Under the optimum conditions, the enrichment factors of the five analytes ranged from 230 to 288 fold and the recoveries ranged from 89.3% to 100.1%. The limits of detection (LODs) based on signal to noise of 3 were 0.41-0.79 mu g L-1. Intra-assay and inter-assay precision, expressed as the relative standard deviation (RSD), were <= 5.46% and 5.81%, respectively. The proposed UASEME-GC/FID method was demonstrated to be simple, practical and environmentally friendly for the determination of trace phthalate esters in beverage samples.