Northeast Agricultural University, 600 Changjiang Street, Harbin 150030, PR China; Soil Physics and Land Management Group, Wageningen University & Research, Droevendaalsesteeg 4, 6708PB Wageningen, The Netherlands.
Soil Physics and Land Management Group, Wageningen University & Research, Droevendaalsesteeg 4, 6708PB Wageningen, The Netherlands.
Sci Total Environ. 2018 Mar;616-617:1056-1065. doi: 10.1016/j.scitotenv.2017.10.213. Epub 2017 Oct 31.
This article introduces a simple and cost-saving method developed to extract, distinguish and quantify light density microplastics of polyethylene (PE) and polypropylene (PP) in soil. A floatation method using distilled water was used to extract the light density microplastics from soil samples. Microplastics and impurities were identified using a heating method (3-5s at 130°C). The number and size of particles were determined using a camera (Leica DFC 425) connected to a microscope (Leica wild M3C, Type S, simple light, 6.4×). Quantification of the microplastics was conducted using a developed model. Results showed that the floatation method was effective in extracting microplastics from soils, with recovery rates of approximately 90%. After being exposed to heat, the microplastics in the soil samples melted and were transformed into circular transparent particles while other impurities, such as organic matter and silicates were not changed by the heat. Regression analysis of microplastics weight and particle volume (a calculation based on image J software analysis) after heating showed the best fit (y=1.14x+0.46, R=99%, p<0.001). Recovery rates based on the empirical model method were >80%. Results from field samples collected from North-western China prove that our method of repetitive floatation and heating can be used to extract, distinguish and quantify light density polyethylene microplastics in soils. Microplastics mass can be evaluated using the empirical model.
本文介绍了一种简单且节省成本的方法，用于从土壤中提取、区分和量化低密度聚乙烯（PE）和聚丙烯（PP）微塑料。采用蒸馏水浮选法从土壤样品中提取低密度微塑料。使用加热法（在 130°C 下加热 3-5 秒）来识别微塑料和杂质。使用连接显微镜的相机（Leica DFC 425）来确定颗粒的数量和大小（Leica wild M3C，Type S，简单光，6.4×）。使用开发的模型进行微塑料的定量分析。结果表明，浮选法是从土壤中提取微塑料的有效方法，回收率约为 90%。暴露于热量后，土壤样品中的微塑料融化并转化为圆形透明颗粒，而其他杂质，如有机物和硅酸盐，不受热量影响。加热后微塑料重量和颗粒体积（基于图像 J 软件分析的计算）的回归分析显示出最佳拟合（y=1.14x+0.46，R=99%，p<0.001）。基于经验模型方法的回收率>80%。来自中国西北地区野外样本的结果证明，我们重复浮选和加热的方法可用于提取、区分和量化土壤中的低密度聚乙烯微塑料。可以使用经验模型来评估微塑料的质量。
