| The ultraviolet radiation from 290 to 400 nm would be absorbed by ultraviolet absorber(UVA),which would effectively inhibit or slow down the degradation of polymer materials due to photo-oxidation.UVAs has become an important addition components of plastics,fibers,coatings and adhesives.The UVAs would be classified into benzophenones,benzotriazoles,salicylates,triazines and substituted acrylonitr iles and so on according to its chemical structures,wherein the benzotriazole ultraviolet absorber is the largest consumption of ultraviolet absorptive of light stabilizer.The ultraviolet absorber in plastic products can improve the durability of materials,however,there are hidden dangers of migration and dissolution in the long-term using of UVAs.Especially the ultraviolet absorber in plastic food packaging materials have attracted wide attention due to their endocrine disruption effects and potential threat to human health.Therefore,many countries and regions incorporated the allowable residue and the migration of ultraviolet absorbers in food packaging materials into the regulations.In this paper,we focused on the potential threat to human health of adding benzotriazole UV absorbers in food packaging materials,and it have great significance to speed up a method of benzotriazole-based light stabilizers in plastic food packaging materials analysis method for accelerating the standardization of detection methods of UV absorbers in food contact materials and protection of consumer food health.For the scope of research objects,considering the addition type and use frequency of benzotriazole ultraviolet absorbers,8 kinds of benzotriazole UV absorbers such as UV-P,UV-234 were selected as the research objects in this paper.On the selection of the detection methods,a simple,rapid and sensitive high performance liquid chromatography-diode array method was used for the analysis of 8 kinds of benzotriazole-based ultraviolet absorbers of various types and polar ities.In the choice of pretreatment,high efficiency and rapid ultrasonic extraction technology was adopted.A high performance liquid chromatography-diode array detection(HPLC-DAD)method has been developed for the simultaneous determination of 8 kinds of UV absorbers in plastic food packaging materials by optimizing the pre-treatment conditions and high-performance liquid chromatography detection conditions.The main conclusions are as follows:1.The effects of ultrasonic extraction conditions such as extraction temperature,time and extractant dosage on the extraction efficiency of target substances in plastic food packaging materials were investigated by selecting the extraction solvent.The pretreatment conditions of eight benzotr iazole UVAs in food packaging materials were established when the extraction time was 10 min and the extraction temperature was 20 ? with 5 mL ethyl acetate / methylene chloride(volume ratio 4: 1)as extraction agent.2.A HPLC-DAD method for the determination of eight benzotriazole-based UVAs in plastic food packaging was developed by selecting chromatographic conditions such as optimized mobile phase,gradient elution program,flow rate and detection wavelength.The mobile phase was methanol-acetonitrile-water as gradient elution,the flow rate was 0.7 mL/min with 95% methanol + 5% acetonitrile at 0 min;0.7 mL/min with 95% methanol + 5% water at 8 min;1 mL/min with 100% methanol at 11.0 min and after 12.0 min was 2 mL/min,detection wavelength was 340 nm.The results showed that the 8 kinds of target materials were determined simultaneously with good separation within 22 minutes.3.Under the analysis method of 8 kinds of UV absorbers in the plastic food packaging materials established in this paper.there were good linear relationships for UV-P,UV-360 and other six UVAs in the range of 0.02~10mg/L,0.2~10mg/L and 0.1~10mg/L.The correlation coefficients were exceeded 0.9999.The limits of detection(S/N=3)of Instrument were 0.0074~0.1250mg/L.The mean recoveries at 3 spiked levels were 93.7%~114.3%,and the relative standard deviation(RSD)was below 5.0%(n=6).The method was simple,sensitive and accurate,and could provide technical support for monitoring the amount of UV absorbers in plastic food packaging materials. |
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