Fast determination of phthalate ester residues in soft drinks and light alcoholic beverages by ultrasound/vortex assisted dispersive liquid-liquid microextraction followed by gas chromatographyion trap mass spectrometry

An ultrasound/vortex assisted dispersive liquid-liquid microextraction (USVADLLME) procedure coupled with gas chromatography-ion trap mass spectrometry (GC-IT-MS) is proposed for the rapid determination of seven phthalate esters in soft drinks and light alcoholic beverages (up to 6% alcohol by volume). Under the optimum conditions, the enrichment factors of the seven phthalate esters ranged from 205-fold to 315-fold for soft drinks and from 172-fold to 285-fold for light alcoholic beverages. The recoveries varied between 94.2% and 99.6% for soft drinks and 95.6% and 99.4% for light alcoholic beverages. The limits of detection were between 0.03 and 0.10 pg mu L-1 and the limits of quantification were between 0.11 and 0.28 pg mu L-1. The intra-day and inter-day precision expressed as the relative standard deviation varied between 2.9% and 5.1% and between 5.5% and 7.6%, respectively. The proposed USVADLLME-GC-IT-MS method was demonstrated to be simple, reproducible and practical for the determination of trace amounts of seven phthalate esters in soft drinks and light alcoholic beverages.