Rapid detection method for content of micro-plastics in water body and application

The invention provides a rapid detection method for the content of micro-plastics in a water body and application, and belongs to the field of environmental pollutant detection. The invention discloses a digestion solution for separating micro-plastics in a water body sample. The digestion solution comprises 10-13 g/L of potassium hydroxide, 0.4-0.8 g/L of sulfathiazole sodium and 0.1-0.7 g/L of naphthylacetamide. The digestion solution can quickly and mildly digest organic impurities in a sample, can avoid mass loss while improving the digestion efficiency, and can protect functional groups of micro-plastics from being damaged in the digestion process. The invention further discloses a method for quantitatively detecting the micro-plastics in the water body based on the TGA-FTIR technology. The method comprises setting of instrument condition parameters, blank determination, drawing of a micro-plastic quantitative standard curve and sample detection. The method can be used for detecting the content of polyam