Determination Of Bisphenols And Phthalate Esters Migrated From Food Plastic Packaging By Dispersive Solid-phase Extraction Coupled With Liquid Chromatography

Bisphenols(BPs)and phthalates(PAEs)are two common environmental estrogens(EEs).BPs are important industrial chemicals.They are mainly used in the industry to synthesize polycarbonate plastics,epoxy resins,polyester resins,which are widely used in the production of food packaging materials.PAEs are common plasticizers in the industry.They can improve the flexibility and durability of plastic products during the production process,so they are widely used in the plastic packaging industry.BPs and PAEs interact with plastic monomers in the form of hydrogen bonds and van der Waals forces.They are easy to migrate from plastic to food contact and cause food pollution due to the weak interactions.In this paper,two adsorption materials were prepared based on the properties of BPs and PAEs,which were used for the extraction of BPs and PAEs that migrated in plastic packaging,Then,BPs and PAEs were sensitively detected by and are combined with high high-performance liquid chromatography.This paper includes the following two parts:(1)Cetyltrimethylammonium bromide-zinc oxide(ZnO@CTAB)was prepared by hydrothermal synthesis.A new method was established combined with UPLC/TOF-MS technology for the determination of BPs migrated in disposable plastic packaging materials used ZnO@CTAB as a dispersive solid-phase extraction(DSPE)adsorbent.Transmission electron microscope(TEM),scanning electron microscope(SEM),nitrogen adsorption-desorption isotherm(BJH),thermogravimetric analysis(TGA),Fourier transform infrared spectroscopy(FT-IR)and X-ray diffraction(XRD)were used to characterized the microscopic morphology,pore size,thermal stability,surface functional groups and crystal structure of ZnO@CTAB materials.The key factors affecting extraction efficiency,such as p H,adsorbent quality,extraction time and eluent types were optimized.Under the optimal conditions,the recovery of the method was 97.63-109.33%and the detection limits were 0.027-0.030?g L^-1.The developed method was used to analyze the types and contents of BPs migrated from commercially available disposable plastic bags and disposable plastic boxes.The migration nature of BPs in the two plastic packagings were investigated.(2)The carbon shell was coated on the surface of Fe₃O₄by hydrothermal synthesis using carboxymethyl cellulose(CMC)as carbon source It was calcined in air to obtain core-shell magnetic nitrogen-doped carbon materials(MNCs).TEM,SEM,FT-IRand XRD and(energy dispersive X-ray spectroscopy)EDX were used to characterize the microscopic morphology,molecular structure,crystal form and element distribution of MNCs.In order to obtain the best extraction efficiency,the effects of the solution p H,the quality of MNCs,the extraction time and the types of eluent were studied.In addition,the Box-Behnken design of response surface methodology was further used to optimize the extraction conditions such as p H value,adsorbent quality,adsorption time and elution time.Using MNCs as magnetic solid-phase extraction(MSPE)adsorbents combined with UPLC-TUV technology,a method for analyzing six PAEs was established and applied to determine the migration of six PAEs in plastic bottled water.Under the optimal conditions,the method showed good linearity(r>0.9984)in the concentration range of 0.2-100?g L^-1,and the detection limits were 0.08-0.26?g L^-1.The method was used to analyze ten plastic bottled water.The results showed that DEHP and DBP were detected in the two kinds of bottled water,while the others were not detected.