Table 1 Microplastics particle identification technical overview ranked by cost (Updated from Thermoscientific (2020) and Bakir et al. 202036,37.
Analytical method | Minimum particle size (μm) | Filter requirement | Degree of automation | Acquisition speed | Advantages | Disadvantages | Relative cost |
|---|---|---|---|---|---|---|---|
ATR-FTIR spectroscopy | > 500 (smaller with care) | N/A | Very low | Fast | - Ease of use - Minimum sample preparation | Contact analysis (ATR) | $ |
FTIR microscopy | > 10 | IR transparent (transmittance measurement configuration) | Low to High (microscope dependent) | Fast | - Ease of use - Minimum sample preparation- | $$ | |
ATR-FTIR spectroscopy with microscope attached | > 5 | Any filter Any substrate | High | Medium | - Ease of use - Minimum sample preparation | Contact analysis (ATR) | $$ |
FTIR imaging | > 5 | IR transparent (transmittance measurement configuration) | Very high | Very fast | - Ease of use - Minimum sample preparation | $$$ | |
ATR-FTIR imaging | > 2 | Any filter Any substrate | High | Medium | - Ease of use - Minimum sample preparation | Contact analysis (ATR) | $$$ |
LDIR imaging | > 10 | Flat, reflective surface (e.g. Kevley slide or IR reflective filter such as gold filters) | High | Very fast | Less commonly used than FTIR, limited reference spectra. Requires more validation for environmental samples | $$$ | |
Raman imaging | > 0.5 | Non-fluorescent | Very high | Fast | Resolving particles down to 1 micron and less | Less commonly used than FTIR, limited reference spectra | $$$ |
Thermal analysis | N/A | - Suitable for nanoplastics identification - Analysis of polymer type and additive chemicals | - Destructive analysis - Reporting unit (mass vs number) - Complex data (pyr-GC–MS | $$$ |
