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 |
$$$ |