Research Progress on Separation and Detection Methods of Microplastics in Soil Environment

As a new type of environmental pollutant, microplastics (MPs) exists in the soil environment for a long time and pollutes the ecological environment of the surface system. Separation and detection of microplastics in soil environment is the basis of controlling microplastics pollution in soil environment. The research progress of separation and detection technology in microplastics was introduced, and the existing problems of separation and detection methods were put forward. The results show that the screening-filtration method and density separation method are simple, operable and effective, but the cross-contamination rate is high in the extraction process, and the recovery rate of high-density microplastics is not high. Pressurized fluid extraction technology is convenient and easy to operate, but it may affect the particle morphology of microplastics. Visual detection, Raman and infrared spectroscopy, chromatography and mass spectrometry combined pyrolysis analysis have some problems, such as high cost, long time and loss of samples. In the future, it is necessary to further explore the analytical method of microplastics, and develop the separation and detection method without loss of microplastics.