Determination of phthalates in food simulants and liquid samples using ultrasound-assisted dispersive liquid-liquid microextraction followed by solidification of floating organic drop

A simple, inexpensive, reliable and environmentally friendly method based on ultrasound-assisted dispersive liquid-liquid microextraction followed by solidification of floating organic drop and gas chromatography-flame ionization detector was developed for the simultaneous determination of five phthalates in food simulants and different food and water samples. Parameters affecting the extraction process were studied and optimized by univariate analysis and experimental design. Under optimum conditions, method showed good linearity in the selected range (R 2 from 0.993 to 0.995). Limits of detection (LOD) ranged from 0.64 to 2.82 µg L−1 and enrichment factors from 854 to 1893. Precision of the method, expressed as relative standard deviation, was checked at two levels obtaining good results (2.7-9.3%). Accuracy of the method was checked in food simulants also obtaining good results. The method allowed determination of phthalates in food simulants at lower concentrations than the migration limits established by the European Union. The developed method was also applied to real water, wine, vinegar and soft drink samples obtaining acceptable results.