热裂解-气质联用技术测试环境土壤中的微塑料

Determination of microplastics in Soil by pyrolizer-GC-MS

本文采用热裂解-气质联用技术分析环境土壤中4种微塑料(聚乙烯、聚丙烯、聚苯乙烯、聚对苯二甲酸乙二醇酯),优化微塑料的测试流程与定性定量分析流程.环境土壤通过密度分离法来分离微塑料,分离富集的微塑料样品通过热裂解气质联用仪测定.结果表明,不同塑料的化学组成和结构有着明显的差异,在高温裂解条件下会产生相应的特征热裂解产物.利用高温裂解产生的特征碎片信息经色谱分离和质谱鉴定,能够有效鉴别塑料成分和进行定量测定.本方法对4种微塑料的检出限为0.1—0.3μg·g^(-1),线性范围为1.0—20.0μg·g^(-1);1.0μg·g^(-1)样品加标回收率范围为81.6%—89.7%,定量重复性为8.9%—15.2%.本方案可以适用于环境中痕量微塑料的分析检测.

In this paper,a Pyrolizer(Py)-GC/MS method was established for the determination of 4 microplastics(MPs)(polyethylene,polypropylene,polystyrene and polyethylene terephthalate)in the environment soil samples.The microplastics in the environmental soil is separated by density separation method.All the MPs get from samples is transferred and analyzed to PY-GCMS system.The results show that obvious differences among different MPs is found in the chemical composition and structure.It will produce corresponding characteristic pyrolysis products under the high temperature condition in pyrolizer system.And the characteristic fragment is used for MP qualitative analysis and quantitative analysis used GC/MS.The determination limit of the four MPs is 0.1—0.3μg·g^(-1),and the linear range is 1.0—20.0μg·g^(-1).The recoveries are between 81.6%to 89.7%with the repeatability of 8.9%—15.2%in 1.0μg·g^(-1) spiked samples.The results show that the Py-GC/MS method is suitable for the MPs determination in environment samples.