MICROPLASTICS ANALYSIS SOLUTIONS- FTIR & RAMAN SPECTROSCOPY

What are Microplastics?

Microplastics are tiny plastic fibers and fragments (smaller than 5 mm in size) that are polluted into the environment from plastics used in everyday items and manufacturing processes.

They are predominantly made up of polystyrene, polypropylene and polyethene and can be divided into two types:

1. Primary microplastics: 

Directly released into the environment (e.g. microbeads in facial cleansers)

2. Secondary microplastics: 

Originate from the degradation of larger plastic objects over time.

How Do You Analyze Microplastics?

Fourier Transform Infrared (FTIR) and Raman spectroscopies have long been used for the analysis of polymers, and it is, therefore, natural that they be the de facto techniques to identify microplastics.

These techniques use the ability of light to interact with molecules causing them to vibrate at given frequencies. As a result, a spectrum (or a peak pattern of absorbed or emitted frequencies – Figure 1) can provide a “molecular fingerprint” of a microparticulate, providing the identity of its components.

For particles >1 μm, the Thermo Scientific DXR3xi Raman Imaging Microscope offers the analytical power to discern microplastics from other contaminants with high-spatial-resolution down to 0.5 µm. The multivariate analysis algorithms of the Thermo Scientific OMNIC Software allows for spectral identification across a spectral library of plastics and polymers. The DXR3xi Raman Microscope has auto alignment and calibration capabilities to ensure accurate measurements and consistency between operators, supporting recommendations made by the EPA working group. This microscope quickly images large surface areas across the sample filter, making it a fast, reliable method for comparing multiple particulates and identifying their chemical components.

For microplastic particles >10 μm, the Thermo Scientific Nicolet iN10 MX FTIR Imaging Microscope offers similar chemical imaging capabilities with speed and efficiency.