Studies On The Determination And Migration Of Phthalate Esters In Food

Eight phthalate esters (DEP,DPP,DBP,DiBP,DAP,DHP,BBP,DEHP) have been studied by gas chromatography, gas chromatography-mass, high performance liquid chromatography technology in this thesis. The effect of operating condition of gas chromatography such as flow rate, temperature of injection, detector and column and high performance liquid chromatography such as mobile phase on the response and separation of PAEs are investigated and acquire optimum operating condition. The ranges of linearity, corrections of linearity and the detection limits for the three simultaneous determinations of eight PAEs also have been compared.The thesis has established the milk sample preparation method by a series of different experimentations. The average recoveries of phthalate esters are between 77.9% and 109.1%, the relative standard deviations (RSD) from 1.72% to 6.18%, the results show that this method is accurate and credible.The thesis set up the water sample solid-phase extraction method by a series of experimentations such as dilute solvent, dilute volume and dilute rate. The results show that the average recoveries of phthalate esters are from 71% to 97.4%, the relative standard deviations between 2.5% and 5.1%, it show this method is accreted and credible.The extraction method of phthalate esters from oil was built up by different experiments such as extraction solvent, extraction times. The recoveries of phthalate esters are between 50% and 98.9%, the relative standard deviations from 1.2% to 3.4%.The method of extraction phthalate ester in plastic was systematically studied such as extraction solvent, extraction temperature and extraction time. The results indicated that the content of phthalate esters in polyethylene is between 7.64 and 55.9 mg/kg, polyethylene terephthalate is from 3.12 to 6.24 mg/kg.The rule of transfer of phthalate esters from plastic packing to food have been investigated using four types of simulant foods. The parameters were systematically studied, such as time, temperature, vibrating frequency and pH. It was found that special migration of phthalate esters were arranged in the following order: isooctane, 15%ethanol, 3%acetic acid and water. The special migration of phthalate esters increased as the time prolonged and temperature raised. Vibrating frequency showed less impact on the special migration than time and temperature, but phthalate esters increased as the vibrating frequency or in the acidic and alkalescent conditions.The migration transfer of phthalate esters from polyethylene to milk have been studied through the experiment conditions, such as storing temperature and storing time. The results show the special migration of phthalate esters increased as the time prolonged, temperature raised and the more phthalate esters in plastic packing.The thesis set up simple analytical mathematical models for migration using Fick principle and diffusion coefficient. Compared with experiments, model prediction was more cheap. The model can estimate the worst content of migration.