Extractable impurities from fluoropolymer-based membrane filters - interference in high-throughput, untargeted
Perng Yang Puah1, Dexter Jiunn Herng Lee2, Ken Hing Mak3
1Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah Jalan UMS 88400 Kota Kinabalu Sabah Malaysia siatyee@ums.edu.my.
RSC Advances
|June 15, 2022
Summary
Fluoropolymer membrane filters can leach impurities into samples, affecting analysis. Pre-conditioning PTFE filters reduces impurities, but PVDF filters remain problematic for untargeted mass spectrometry.
Area of Science:
- Analytical Chemistry
- Materials Science
- Chromatography
Background:
- Fluoropolymer membrane filters are used to protect analytical columns and hardware.
- These filters can inadvertently introduce impurities into samples during filtration.
- Such impurities pose a significant challenge in high-throughput, non-targeted analyses.
Purpose of the Study:
- To investigate extractable impurities eluted from various brands of fluoropolymer membrane filters.
- To assess the impact of pre-conditioning on impurity levels in PTFE and PVDF filters.
- To determine the suitability of different membrane filters for mass-spectrometry-based untargeted analysis.
Main Methods:
- Filtration of samples through different brands and materials of fluoropolymer membrane filters.
- Analysis of filtrate for extractable impurities using principle component analysis (PCA).
- Evaluation of impurity levels after multiple pre-conditioning cycles (up to 3 times).
Main Results:
- Significant variation in impurity elution was observed between different membrane filter brands and materials.
- Extractable impurities persisted in both filters and filtrates even after multiple pre-conditioning steps.
- PTFE filter pre-conditioning showed potential to reduce impurities, while PVDF filters consistently eluted impurities.
- PCA indicated that filtrates differed from unfiltered samples, with PVDF filtrates clustering by brand post-conditioning.
Conclusions:
- Pre-conditioning of PTFE membrane filters is recommended to minimize false positives in analytical results.
- PVDF membrane filters are not recommended for mass-spectrometry-based untargeted analysis due to persistent impurities.
- Using diverse filter brands or materials within a single sample batch is discouraged due to variable impurity profiles.
