Detection Techniques And Methods Of Several Harmful Substances Released From The Paper Food Contact Materials

Paper food contact materials is an integral part of people’s lives, and paper foodcontact materials relative to the plastic food contact materials is more environmentalprotection and healthier. In recent years, Chinese total imports and exports of paperfood contact materials is increasing rapidly. With the expansion of the scope of thefood safety, rules on food contact materials are also improving. Paper food packagingis also likely to be contaminated because varieties of functional additives need to beadded during processing. Consequently, maybe there are bacteria, oil-proofing agents,plasticizers, primary aromatic amines, fluorescent brighteners, inks, heavy metals andother hazardous substances in it, these substances can migrate to food duringcontacting with food, which endanger people’s health. Therefore, the research of themigration of harmful substances in paper food contact materials is very important toensure food safety.In this paper, on the basis of domestic and foreign researches and combiningwith the latest domestic and foreign regulatory requirements, had a study on dectionmethods of migration of phthalic acid esters, primary aromatic amines and fluorescentbrighteners from paper food contact materials. A solid phase extraction (SPE)-highperformance liquid chromatography (HPLC) method has been developed for thesimultaneous determination of ten phthalic acid esters (PAEs) in four food simulants.A liquid chromatography tandem mass spectrometry (LC-MS-MS) method has beendeveloped for the simultaneous determination of24primary aromatic amines (PAAs)released from Food Paper Packaging Materials in seven food simulants, and built theextraction method of24PAAs in olive oil for the first time. A HPLC method has beendeveloped for determination of fluorescent brightener220in seven food simulants forthe first time, and built the extraction method of fluorescent brightener220in olive oil.1. Ten PAEs were analyzed by HPLC-DAD (diode array detector). The bestanalysis conditions: acetonitrile (mobile phase A) and ultra-pure water (mobile phaseB) as mobile phases; injection volume:20μL; column temperature:30°C; flow rate:1.0mL/min; detection wavelength:224nm; column: Eclipse XDB-C18(4.6mm×150mm,5μm). Gradient elution conditions:0~3min，65%A；3~20min，65%~95%A；20~30min，95%A；30~31min，95%~65%A；31~35min，65%A.With distilled water,3%acetic acid,10%ethanol and95%ethanol instead of thedifferent types of food simulated the migration of PAEs from food paper contactmaterials, PAEs in food simulants were enriched and purified by C18solid phaseextraction column and nitrogen blowing, the optimal volume of acetonitrile eluate was10mL. The method showed correlation coefficients of calibration curves were higherthan0.9999, recoveries at spiked different levels ranged from71.27%to106.97%, therelative standard deviations were0.86%~8.00%, and limits of quantitation weren’tlarger than0.35mg/kg. The method had high sensitivity and good accuracy, the limitsof quantitation met the limited requirements of the relevant laws and regulations.2.24PAAs were analyzed by LC-MS/MS. Establishing mass spectrometerconditions of24PAAs: the positive electrospray ionization; Multiple ReactionMonitoring mode; optimizing and establishing the precursor ion, the product ion, thedeclustering potential, the entrance potential, the collision energy and the collisioncell exit potential of every PAA. The best liquid chromatography analysis: acetonitrile(mobile phase A) and0.1%formic acid (mobile phase B) as mobile phases; injectionvolume:10μL; column temperature:30°C; column: ZORBAX SB-C18（2.1mm×150mm，5μm）. Gradient elution conditions:0~5min，15%A，flow rate：0.3mL/min；5~15min，15%~90%A，flow rate：0.3~0.5mL/min；15~20min，90%A，flow rate：0.3mL/min；20~20.1min，90%~15%A，flow rate：0.5~0.3mL/min；20.1~25min，15%A, flow rate：0.3mL/min. With distilled water,3%aceticacid,10%ethanol,20%ethanol,50%ethanol,95%ethanol and olive oil instead ofthe different types of food simulated the migration of PAAs from food paper contactmaterials. Optimizing the ultrasonic extraction conditions of24PAAs in olive oil by orthogonal experiment, when acetonitrile (2g olive oil) extraction reagent volume was6mL, ultrasonic power was400W, ultrasonic temperature was30°C, ultrasonic timewas20min, extraction effect was the best, and temperature had a significant impact onthe extraction effect. The method showed correlation coefficients of calibration curveswere0.9876~0.9999, recoveries at spiked different levels ranged from0.30%to90%,the relative standard deviations were70.30%~97.88%, and limits of quantitationweren’t larger than3.0μg/kg. The method had high sensitivity and good accuracy, thelimits of quantitation met the limited requirements of the relevant laws andregulations（＜0.01mg/kg）.3. Fluorescent brightener220was analyzed by HPLC–FLD (fluorescencedetector). The best analysis conditions (except3%acetic acid simulant): methanol andultrapure water as mobile phases; injection volume:20μL; column temperature:30°C;flow rate:1.0mL/min; excitation wavelength:360nm, emission wavelength:430nm;column: Agilent Hypersil SI (200mm×4.6mm,5μm); isocratic elution conditions:ultrapure water: methanol(40:60),5min. Liquid chromatography analysis conditionsof fluorescent brightener220in3%acetic acid simulant: acetonitrile and ultrapurewater as mobile phases; isocratic elution conditions: ultrapure water: acetonitrile(10:90),5min; other conditions stayed the same. With distilled different foodsimulants instead of food simulated the migration of fluorescent brightener220fromfood paper contact materials, fluorescence response value of fluorescent brightener220in3%acetic acid simulant was significantly lower than other mimetic, N,N-dimethyl formamide has good ultrasonic extraction effect for fluorescentbrighteners220in olive oil. The method showed correlation coefficients of calibrationcurves were0.99012~0.99992, recoveries at spiked different levels ranged from90.22%to98.77%, the relative standard deviations were0.47%~3.27%. Limit ofquantitation of Fluorescent Brightener220in3%acetic acid simulant was1.5mg/kg,12μg/kg in olive oil simulant,5μg/kg in other simulants. The method had lower limitof quantification, high precision and accuracy.