Study On The Detection And Migration Of PFCs In Food Contact Materials

Perfluorinated compounds(PFCs) are a new persistent organic pollutants which enjoy a great variety.However GB GBT23243-2009 Determination of Perfluorooctane sulfonate(PFOS) in food packaging materials-high performance liquid chromatoghraphy-tandem mass spectrometry only gives the detection method of perflurooctane sulfonate(PFOS). This paper was first established the methods for the determination of 7 PFCSin 4 kinds of food contact materials(popcorn bucket, barbecue oiled papers, hamburg bags and egg tart tinfoil) by solid phase extraction couple with liquid chromatography-tandem mass spectrometry(SPE-LC-MS/MS). The rapid quantative detection of PFCs were finished in 7 minutes by comparison and optimization the pretreatment and instrument conditions. In the extration method,compared with rapid solvent extration given in GB,we select ultrasonic extration as the extration method which is more simple.It requires low experimental condition and saves gagents. In order to reduce the complexity of the instrument matrix pollution as well as improving the detect limit,we add solid-phase column to concentrate ane purified the matrix. In instrument conditions,the column of C18 was used in the national standard.The peak shape was improved by adding 10 mmol / L ammonium acetate to the inorganic phase. In this article,we use the column of C8 and it can achieve a good separation and peek shape by adding 2 mmol / L ammonium acetate.It also reduces the damage to mass spectrometer by high concentration of salt. The detection limit of the method was 0.014 ~ 0.063 μg/kg which is lower than 0.285 μg/kg lined in GB.The method enjoys good accuracy and reproducibility with average recoverisand the RSD for repeated measurements(n=6) were 77.0%~110.7%and 2.7%~8.8%.The detection of PFCs in food contact materials in foreign contries is mostly internal standard, the most prominent advantage of this method is that we it can achieve same effect by using external method.It is no need to find lots of internal standard or tedious operation,the instrumentcomes with the autosampler can minimize this error resulting from the external method.The method has been applied in real food contact materials selecting from the market,and the instrument conditions was extended to detect seven kinds of PFCs in Guiyang edible oil by Gui Zhou Province Analysis an Testing Institute.The results showed that there is a good precision and reproducibility and it gives aa comprehensive understanding of currently marketed food contact materials and contamination in edible oils. PFCs added is below the minimum limits specified in the EU.It provides more extensivesupportingdata with a view to exposureroute, exposure levels of PFCs.Powder polystyrene(PS) as the most plastic additive in food contactmaterials,in the forth chapter,the soption of PFOS in water was simulated by optimizing the per-equilibration time and the adsorption equilibrium time.Using pseudo-first-and second-order kinetic equation to fit gives the information that first-order kinetics model can better describe the PS adsoption behavior on PS powder. We conclude that PFHxS and PFOS have the common adsorption sites by studing the competitive adsorption of PFHxS and PFOS. The adding of PFHx S leads a decline adsoption amount of PFOS,its degree is releated to the concentration of PFCs in the solution. Both the types and concentrations of PFCs are the factors which influence the immigration of PFCs in the medium. In this experiment, the adsorption mechanism of PFCson plastic contact materials was studied,in order to get a deeper undersstanding of the immigration mechanism of PFCs to food.