Study On The Determination And Migration Of Phthalates In Plastic Food Packaging

Phthalates(PAEs)is one of the plastic additives in the plastic.It is used in the chemical industry,food,cosmetics,medicine and many other industries.It has a certain damage to the human body's immune system,reproductive system,nervous system,and even cancer,so the whole world is strictly controlled by the use of phthalate plasticizer.Aiming at the content of PAEs in plastics,its migration in the plastic and so on are going on researching at home and abroad.In this paper,the experiment was through three aspects: Established the pretreatment methods of extraction PAEs in plastics;Study on new method of detection of PAEs in plastics;Simulation experiment on migration of food plastic packaging.First of all,in the pretreatment experiment of the plastic.It was explored in the extraction method,extraction solvent,solvent amount,temperature,time five single factors by control variable method,And then choosing the influence three factors to carry on the orthogonal experiment.The best pretreatment conditions were obtained..The final result was the selection of ultrasonic extraction,extraction solvent for hexane,the extraction time for 90 min,the extraction temperature for 35?.Under this condition,the extraction amount of PAEs in the food plastic was reached the equivalent of the national standard or other documents before treatment and the effect of the improvement.And the pretreatment of this experiment saves the reagent dosage,energy,time and so on.Secondly,this study explored a new method of using ultra performance convergence chromatography of Waters company to detect 15 kinds of phthalate esters quickly.In this experiment,the rapid detection method of phthalate esters was studied by UPCC.By optimizing the column,column temperature,flow rate,modifying agent,mobile phase,back pressure,and other eight factors,establishing a method for the detection of 15 phthalate esters by UPCC.Column chromatography was ACQUITY UPC~2 HSS C18 SB(150 mm×3 mm,1.8 ?m),supercritical CO2 fluid as mobile phase and using acetonitrile as solvent to carry out gradient elution.The flow rate was 1.5 mL/min,and system back pressure was 12.41 MPa.Column temperature was 65?.Sample quantity was 3 uL.Under the detection wavelength of PDA was 220 nm,15 kinds of phthalate esters could be separated and detected with 8 min.In the 0.5~10 mg/L scope,it had the good linear relationship(R2 >0.996).The detection limit was in the ranged of 1.0~2.2 mg/kg.The recovery rate was in the ranged of 78.1~122.3%,and the relatives standard deviation was in 2.95~8.26%.The method greatly reduced the use of organic reagents,to meet the needs of the establishment of green environmental protection analysis method,and reduce the cost of detection.Finally,in order to simulate the migration of toxic and hazardous substances in plastics,so it was the choice of 24 hours,50 degrees conditions and 10 days,room temperature conditions of the two models simulation experiment and choice of distilled water,4% acetic acid solution,50% ethanol solution,octane four kinds of simulation solution to complete the whole experiment.Results showed that plastic in the original four plasticizers(diisobutyl phthalate(DIBP),dibutyl phthalate(DBP),dicyclohexyl phthalate(DCHP),Bis(2-ethylhexyl)phthalate(DEHP))had different migration rules:(1)Whatever DBP was in low temperature and high temperature,it was the most easy to migrate out of a plasticizer.and the concentration of DBP in the high temperature was a lot of times in the room temperature.At the same time,the order of DBP migration in the four kinds of simulation is 50% ethanol > octane > 4% acetic > distilled water.(2)The DIBP in distilled water and 4% acetic was almost no emigration.In the 50% ethanol and octane in the high temperature in a short time there were to move out.At low temperature for a long time,only in the 50% ethanol found that there was a move out,So it could be preliminarily concluded that the effect of DIBP on the migration temperature was greater,and it was more soluble in 50% ethanol.(3)Both the DCHP and DEHP were only found in 50% ethanol and octane.Compared them,they moved out of the octane more than the 50% ethanol,so DCHP and DEHP were more soluble in octane.Because they were similar in structure and property,the migration rules were similar.(4)The 24 hour simulation of Migration Experiment showed that the amount of emigration of four substances in the four analog in 2-3 hours was relatively small or not.But in 8-9 hours later,the amount of migration was two times of the beginning even more.(5)In the ten day simulation of Migration Experiment,the whole process was constantly moving out,but the amount of the migration had a difference.In the first 3 days the amount of migration could be understood in a safe range.(6)According to the actual life,it was found that several kinds of plasticizer were more soluble in alcohol and fat food,and the second was acid food,the most difficult to dissolve in water.