Capture and characterisation of microplastics printed on paper via laser printer's toners

Microplastics are among the ubiquitous contaminants in our environment. As emerging contaminants, microplastics are still facing with lots of challenges on the characterisation, including their capture, identification and visualisation, particularly from a complex background. For example, when we print documents using a laser printer, we are printing micmplastics onto paper, because the plastics are the main ingredient of the toner powder mixture. Characterisation of these micmplastic mixture meets an even more complicated challenge, because plastic's signals might be shielded by other toner powder ingredients such as the pigments, the dyes, the black carbon, and the paper fabrics as well. To solve this challenge, we employ various techniques, including SEM, TEM, XPS, FT-IR, TGA and Raman, to characterise the micmplastics printed via the toner powders. Interestingly, we show that Raman can distinguish and visualise the distribution of the microplastics from the complex background of the mixture. We estimate the millions of toner powders, each of which is similar to 4-6 mu m in size, are printed out per A4 sheet as micmplastics. The findings send a strong warning that millions of microplastics might be generated from the printing activities in our daily lives.