Microplastics are considered an environmental issue because they can be present in different bodies of water, such as sea and freshwater. Any polymeric particles smaller than 5 millimeters are considered a microplastic and the most common materials found are polyethylene and polypropylene; they can be found in plastic bags, and polypropylene is found in food packaging materials such as candy wrappers.
FTIR microscope, which is used especially for imaging, is suitable for particles that have a size between five micrometers and 10 micrometers.
Clear-View ATR micro objective lens and ATR Cassegrain can be used to observe the sample directly, without the use of a reflection cassegrain or refractive objective. It is also possible to observe the sample when in contact with the ATR crystal.
After spectra have been collected they are correlated with databases of previously identified chemical compounds, which are used to identify the materials present in the microplastic sample.