Deep Eutectic Solvent-based green extraction and gas chromatography determination of phthalates released from food contact materials

A sensitive and efficient green emulsification liquid-liquid microextraction (ELLME) method using deep eutectic solvents (DES) for extraction of phthalates released from food contact materials (FCMs) was optimized for GC-MS determination of Butyl Benzyl Phthalate (BBP) and Di-2-Ethylhexyl Phthalate (DEHP). The optimal DES system for phthalate extraction was determined to be Choline Chloride:Phenol (1:2 molar ratio). Tetrahydrofuran (THF) was utilized as the emulsifier solvent. The effects of vortex agitation times and centrifugation times on extraction efficiency were investigated. The method yielded quantification limits (LOQ) of 0.036 and 0.005 mgL−1 for BBP and DEHP, respectively. Repeatability relative standard deviations (RSDr) of 2.9% and 2.2% were obtained for BBP and DEHP, respectively, while corresponding medium precision relative standard deviations (RSDR) were 2.8% and 3.2%. Recovery rates from spiked samples were 94.8% for BBP and 95.1% for DEHP. Finally, determination of BBP and DEHP released from contact materials into water and beverage samples at various temperatures confirmed the applicability of the method for assessment of phthalates and their migration from FCMs.