气相色谱—质谱法测定涂漆筷子中28种有机化合物迁移量及其迁移规律和风险评估研究

Determination of Migrations of 28 Organic Compounds in Painted Chopsticks by Gas Chromatography-Mass Spectrometry and Research of Their Migration Rules and Risk Assessment

鉴于目前没有涂漆筷子中醇类、酮类、酯类等有机化合物迁移量的相应检测标准,并且缺乏目标物迁移规律和风险评估的文献报道,进行了题示方法研究。考虑到涂漆筷子会接触油性食品,选择玉米油、异辛烷和95%(体积分数,下同)乙醇溶液等3种油基模拟物,按照GB 31604.1-2015和GB 5009.156-2016的要求,在迁移时间2 h、迁移温度70℃条件下进行迁移试验。取迁移试验得到的玉米油模拟物5.0 g至20 mL顶空瓶中,加入50μL甲醇,于120℃平衡30 min,释放的气体进入气相色谱-质谱联用仪,采用DB-624毛细管柱(60 m×0.32 mm,1.8μm)以柱升温程序分离28种有机化合物,在选择离子监测模式下进行检测;取迁移试验得到的异辛烷模拟物或95%乙醇溶液模拟物1.0 mL至进样瓶中,无需顶空处理,按照相同的气相色谱-质谱条件进行检测,采用基质匹配的混合标准溶液系列绘制工作曲线。结果显示:3种油基模拟物基质中检出目标物的质量分数均在0.01~0.50 mg·kg^(-1)内与其对应的峰面积呈线性关系,检出限(3S/N)为0.51~1.03μg·kg^(-1);对空白油基模拟物进行加标回收试验,回收率为80.1%~120%,测定值的相对标准偏差(n=6)为1.6%~9.8%。探究阳性涂漆筷子中28种有机化合物在不同模拟物、不同迁移时间和不同迁移温度下的迁移规律,结果表明,目标物在95%乙醇溶液中的迁移量较大,并且迁移时间越长、迁移温度越高,目标物越容易发生迁移。按照环保部公布的经口致癌风险模型和非致癌风险模型对涂漆筷子中的迁移物进行风险评估,结果表明,在95%乙醇溶液,60℃和10 d的迁移条件下,检出正丁醇、乙酸丁酯、乙苯、对/间二甲苯、丙二醇甲醚乙酸酯、邻二甲苯、苯乙烯,迁移量为0.018~1.453 mg·kg^(-1),健康风险指数均小于1,说明涂漆筷子中目标物迁移到食品模拟物的暴露量处于低风险水平。

In view of the lacks of relevant standards for the determination of migrations of organic compounds such as alcohols,ketones and esters in painted chopsticks,and literatures about migration rules and risk assessment of the targets,the method as mentioned by the article was studied.Considering that the painted chopsticks would contact oily food,3 oil-based simulants including corn oil,isooctane and 95%(volume fraction,the same below) ethanol solution were selected to conduct migration test at conditions of 2 h of migration time and 70 ℃ of migration temperature according to the requirements from GB 31604.1-2015 and GB 5009.156-2016.The corn oil simulant(5.0 g) obtained by migration test was added into a 20 mL-headspace bottle,and 50 μL of methanol was added.The mixed solution was balanced at 120 ℃ for 30 min.The released gases were entered into gas chromatography-mass spectrometer,and then 28 organic compounds were separated by column heating program using DB-624 capillary column(60 m×0.32 mm,1.8 μm),and detected with selective ion monitoring mode.The isooctane simulant(1.0 mL) or 95% ethanol solution simulant(1.0 mL) obtained by migration test was added into a sample bottle,and determined by the same conditions of gas chromatography-mass spectrometry,and the working curves were drawn using the matrix matched mixed standard solution series.It was shown that linear relationships between the values of mass fraction and peak area of the detected targets in the 3 matrixes of oil-based simulants were kept in the range of 0.01-0.50 mg·kg^(-1),with detection limits(3S/N) in the range of 0.51-1.03 μg·kg^(-1).Test for recovery was made on the blank oil-based simulants,giving results in the range of 80.1%-120%,and RSDs(n=6) of the determined values ranged from 1.6% to 9.8%.The migration rules of 28 organic compounds in positive painted chopsticks were investigated under different simulants,different migration time and different migration temperatures.The results showed that the migration amounts of the targets were larger in 95% ethanol solution,and the targets migrated easier with the longer migration time and the higher migration temperature.According to the oral carcinogenic risk model and non-carcinogenic risk model published by the Ministry of Environmental Protection,the risk assessment of the migrators in painted chopsticks was carried out.The results showed that at the migration conditions of 95% ethanol solution,60 ℃ and 10 d,n-butanol,butyl acetate,ethylbenzene,p-/m-xylene,propylene glycol methyl ether acetate,o-xylene and styrene were detected,with migration amounts ranged from 0.018 mg·kg^(-1) to 1.453 mg·kg^(-1),and the health risk indexes were less than 1,indicating that the exposure of targets migrating to food simulant from painted chopsticks was at low risk level.