土壤和植物中微塑料研究现状分析及检测方法研究进展

Microplastics in soils and plants:Current research status and progress on detection methods

微塑料(MPs)是指尺寸上限为5 mm的聚合物。作为一种新兴污染物,MPs广泛存在于海洋、陆地等不同环境中。研究发现,陆生环境是MPs一个重要的“汇”,其MPs的含量是海洋环境的4~23倍,MPs不仅影响土壤环境,还能够进入植物组织,并通过食物链等途径进入人体内,引发健康风险,成为迫切需要解决的环境污染问题。检测技术是研究环境污染物不可或缺的一个手段,关于陆生生态系统的研究刚起步,MPs检测技术还未发展成熟。目前,关于微塑料的检测主要分为前处理和分析检测:密度浮选、筛分过滤、萃取和消解等方法是前处理中常用的方法;定性定量检测以目检法、光谱法和质谱法为主,其中场发射扫描电镜(SEM)、激光共聚焦显微镜(CLSM)、拉曼光谱(Raman)、傅里叶变换红外光谱(FTIR)和热裂解气相色谱/质谱法(Py-GC/MS)是最常用的仪器方法。而当面对复杂的环境样品时,往往需要结合多种方法进行分析。因此,本文通过文献整理,综述土壤及植物中MPs检测方法进展、不同检测技术的适用条件及优缺点,旨在为未来陆生生态系统MPs定性定量、MPs在植物中转移积累规律的研究提供科学参考。

Microplastics(MPs)are tiny plastic particles less than 5 mm in length.As an emerging pollutant,MPs are widely found in the marine and terrestrial environments.It has been found that the terrestrial environment is an important sink for MPs,where the content of MPs is 423 times higher than the marine environment.Microplastics not only affect the soil environment,but also can enter plant tissues and the human body through food chain or other pathways,posing health risks and becoming an urgent environmental problem.Detection technology is an indispensable tool for the study of environmental pollutants,but research on terrestrial ecosystems is still in its infancy and detection technology for MPs is still developing.At present,the detection of microplastics is ususally done in two steps:sample pretreatment and sample analysis.Density flotation,sieving and filtering,extraction and disintegration methods are commonly used for sample pretreatment,and visual inspection,spectroscopy and mass spectrometry are used for qualitative/quantitative sample analyses—with field emission Scanning Electron Microscopy(SEM),Confocal Laser Scanning Microscope(CLSM),Raman spectra(Raman),Fourier Transform Infrared Spectrometer(FTIR)and Pyrolysis-Gas Chromatography/Mass Spectrometry(Py-GC/MS)most commonly used.For complex environmental samples combination methods are often required.Thus this paper summarizes research progress on detection methods for MPs in soils and plants,and discusses the application conditions and advantages and disadvantages of different detection techniques,aiming to provide a scientific reference for future studies,qualitative and quantitative,of MPs in terrestrial ecosystems and MPs transfer and accumulation in plants.