PlastiTrax® QC tablets
| Deuterated Polymers | Deuterated Polystyrene (dPS) | Deuterated Polyethylene (dPE) |
Reliable and reproducible microplastic analysis requires robust quality assurance and quality control (QA/QC). Since microplastics and related contamination are found almost everywhere, unintended inputs or particle losses during sample preparation can affect recovery rates and introduce bias, particularly in complex matrices.
To address these challenges, we use deuterated polymer fragments (dPE and dPS) as internal quality control standards. As these materials do not occur naturally in the environment and exhibit clearly distinguishable IR and Raman spectra, they can be reliably differentiated from conventional microplastics. This makes them ideal for recovery assessment and automated quality control.
By spiking samples with a tablet containing a precisely defined number of dPE and dPS particles, recovery can be determined directly for each analysis. Their physical and morphological similarity to conventional PE and PS in terms of density, morphology, and sample preparation behavior allows them to realistically follow the analytical workflow, improving the transparency, reproducibility, and reliability of microplastic analysis.
Benefits and application:
✔ Clearly distinguishable from environmental microplastics (not naturally occurring)
✔ Applicable to all particle-based analytical methods (µFTIR, Raman, and QCL)
✔ Precise recovery determination for different particle size
fractions (25–50, 50–100, and 100–200 µm)
✔ Enables the implementation of an automated QA/QC system
✔ Reduces bias in recovery rates
✔ Suitable for complex and contamination-prone matrices
✔ No optical identification required (no colored fragments or beads needed)
✔ High physical similarity to conventional PE and PS
✔ Defined particle numbers ensuring full traceability
✔ Improved reproducibility and data quality
✔ Traceable quality assurance for routine analyses
Optical comparison of polystyrene (PS)
and deuterated polystyrene (dPS)
The figure shows the 50–100 µm fraction of polystyrene (PS) and deuterated polystyrene (dPS), recorded with an optical microscope on a gold-coated substrate. Both fragments appear optically identical in terms of size, shape, and contrast, highlighting their strong physical similarity. Only spectroscopic analysis allows dPS to be clearly distinguished from conventional PS, making it an ideal internal standard for quality control applications.
Spectral differences in µFT-IR for PS and dPS
Although polystyrene (PS) and deuterated polystyrene (dPS) appear identical under an optical microscope, they exhibit significant spectral differences. These differences arise from isotopic labeling, where hydrogen (¹H) in PS is replaced by deuterium (²H) in dPS. As a result, the C–H vibrations shift to lower wavenumbers and appear as C–D vibrations. This characteristic shift enables the clear spectroscopic identification of dPS and makes it an ideal internal standard for microplastic analysis.
Spectral differences in µFT-IR for PE and dPE
Similar to PS and dPS, polyethylene (PE) and deuterated polyethylene (dPE) exhibit identical physical properties while remaining clearly distinguishable spectrally. The C–H stretching vibrations typically observed above 2800 cm⁻¹ shift to C–D vibrations at lower wavenumbers due to the isotopic substitution of hydrogen with deuterium. This characteristic spectral shift allows dPE to be reliably differentiated from environmental PE, making it well suited as an internal standard for FTIR-based microplastic analysis.
Spectral differences in Raman-spectroscopy
The same phenomenon is also observed in the Raman spectrum. While conventional polystyrene (PS) exhibits characteristic C–H vibrations, these are replaced by C–D vibrations at lower wavenumbers in deuterated polystyrene (dPS). This spectral shift enables clear differentiation between PS and dPS, making dPS an ideal internal standard for microplastic analysis using Raman spectroscopy.
