Analysis of Volatile Organic Compounds in Printing and Plastic Packaging Materials of Instant Noodles by Headspace Gas Chromatography-Mass Spectrometry
A headspace gas chromatography/mass spectrometric(HS/GC-MS) method was used to analyze seven volatile organic compounds(VOCs) including isopropyl alcohol,ethyl acetate,benzene,butyl acetate,ethylbenzene,m/p-Xylene,o-Xylene in printing and packaging materials of instant noodles.The important experiment parameters related to the HS/GC-MS method were optimized,equilibrium temperature of 80 ℃ and headspace equilibrium time of 40 min.In the experiment,linear calibration curves of the seven VOCs were obtained with correlation coefficients of more than 0.9991,the detection limits were in the range of 0.004-0.007 mg/m2,the recoveries ranged from 93% to 102% with RSD less than 3.1%.The results indicated unprinted plastic film contained isopropyl alcohol,ethyl acetate,butyl acetate,printed plastic film contained the seven VOCs,and the contents of the three VOCs including isopropyl alcohol,ethyl acetate and butyl acetate were higher than unprinted plastic film.Plastic laminated films contained the seven VOCs,the contents of the five VOCs including isopropyl alcohol,ethyl acetate,butyl acetate,m/p-Xylene,o-Xylene were higher than printed plastic film,and the contents of benzene and ethylbenzene were lower.The amount of the seven VOCs in the plastic laminated films was 0.42 mg/m2,and the benzene solvent content was 0.25 mg/m2.The content of VOCs in black ink was higher,followed by yellow ink and magenta ink,while white ink had the lower content.Binder contained isopropyl alcohol,ethyl acetate,butyl acetate,m/p-Xylene,o-Xylene.Reducing benzene solvent contents in printing inks and binder was an important procedure to ensure the safety of the packaging materials of instant noodles.Longer drying time and higher drying temperature could help reduce the residual quantity of VOCs in packages of instant noodles.