太湖水体中微塑料和纳米塑料的鉴定和定量

Identification and Quantification of Microplastics and Nanoplastics in Lake Taihu

近年来,微塑料(<5 mm)已在各种环境甚至生物体中被广泛检出。然而,人们对环境中粒径小于1μm的纳米塑料的赋存还知之甚少。以太湖竺山湾近岸带水体为研究对象,利用不同孔径滤膜通过分级过滤、H_(2)O_(2)消解、过滤富集等方法对水样进行处理,将样品颗粒分成3个尺寸范围(>20、1~20和0.1~1μm)。利用扫描电子显微镜(SEM)、激光红外成像光谱仪(LDIR)与热裂解-气相色谱-质谱联用(Py-GC/MS)等技术手段,综合分析太湖采样点水体中微塑料和纳米塑料的赋存情况。结果显示,水体中纳米塑料(0.1~1μm)主要以PET、PP和PS为主,并且其含量远高于微塑料。已有研究证明纳米塑料有更高的生态健康风险,因此需要对环境中纳米塑料的赋存情况进行精准的定性及定量分析。

In recent years,microplastics(MPs)with a particle size of less than 5 mm have been extensively detected in various environments,including organisms.However,there is limited knowledge about the occurrence of particles smaller than 1μm,known as nanoparticles(NPs),in the environment.A water sample was collected from the nearshore water body of Zhushan Bay in Lake Taihu.The sample was separated using membranes with different pore sizes(20,1,and 0.1μm).The samples were then digested using an H_(2)O_(2) solution,concentrated through filtration and drying processes.The particles were divided into three size ranges(>20,1~20,and 0.1~1μm)and subjected to analysis using scanning electron microscopy(SEM),dynamic light scattering(DLS),laser direct infrared(LDIR)spectroscopy,and pyrolysis gas chromatography-mass spectrometry(Py-GC/MS)for identification and quantification of MPs and NPs in the water body of Lake Taihu.The results revealed that NPs in the water,particularly those in the size range of 0.1~1μm,mainly consisted of polyethylene terephthalate(PET),polypropylene(PP),and polystyrene(PS),with their content being significantly higher than that of MPs.It has been demonstrated that NPs pose higher ecological health risks compared to MPs.Therefore,it is crucial to enhance the accuracy of quantitative and qualitative analysis in assessing the occurrence of NPs in the environment.