Overview
PFAS (Per- and Polyfluoroalkyl Substances) analysis requires careful selection of sample containers, vials, caps, and laboratory consumables. Because PFAS compounds are commonly encountered in numerous industrial materials, trace contamination from laboratory supplies can influence analytical results, particularly when using highly sensitive LC-MS/MS and GC-MS methods.
For this reason, RSA-Pro X™ hydrophobic vials and inserts are not recommended for PFAS testing applications.
Why RSA-Pro X™ Products Are Not Recommended
During the RSA-Pro X™ surface-treatment manufacturing process, materials may be exposed to substances that are unsuitable for ultra-trace PFAS analytical workflows.
While these materials generally present no concern for routine chromatography applications, highly sensitive PFAS methods may be capable of detecting trace background signals that could interfere with analytical measurements.
This consideration applies to:
- RSA-Pro X™ vials
- RSA-Pro X™ inserts
- RSA-Pro X™ surface-treated glass products
As a result, alternative sample containment materials should be used for PFAS testing.
Recommended Containers for PFAS Sampling
For field sampling and sample collection, commonly recommended materials include:
- High-density polyethylene (HDPE) containers
- Polypropylene containers
- HDPE closures
- Polypropylene closures
These materials are widely used in PFAS sampling workflows because they help minimize the risk of introducing PFAS-related background contamination during sample collection and storage.
Recommended Vials for PFAS Analysis
For laboratory analysis, polypropylene LC-MS vials are commonly used for PFAS workflows.
Benefits may include:
- Reduced risk of PFAS-related background contributions
- Compatibility with LC-MS systems
- Suitability for trace-level analyses
- Good recovery characteristics for PFAS compounds
Proper vial selection is an important part of maintaining data quality in PFAS methods.
Solvent Considerations
PFAS compounds are frequently prepared and maintained in solution using solvent systems designed to support analyte stability and recovery.
A commonly used preparation solvent is:
- 50% Methanol / 50% Water
This solvent composition is widely used to assist with PFAS dissolution and solution stability throughout the analytical process.
Cap Selection and Best Practices
Closure selection can also affect PFAS results.
Repeated puncturing of septa may introduce variability through:
- Solvent evaporation
- Concentration changes
- Potential analyte loss
To help maintain sample integrity:
- Use sealed replacement caps when appropriate.
- Replace punctured closures rather than repeatedly reusing them.
- Minimize sample exposure during storage and analysis.
These practices can help improve reproducibility and quantitative accuracy.
Sample Handling Recommendations
Prior to analysis, sample homogenization is recommended.
Vortex mixing may help:
- Improve sample uniformity
- Resuspend settled materials
- Improve consistency between injections
This can be particularly important for certain longer-chain PFAS compounds that may settle during storage.
Key Takeaways
- RSA-Pro X™ vials and inserts are not recommended for PFAS analysis.
- Highly sensitive LC-MS/MS and GC-MS methods may detect trace PFAS-related background signals.
- HDPE and polypropylene materials are commonly recommended for PFAS sampling.
- Polypropylene LC-MS vials are frequently used for PFAS analytical workflows.
- Sealed replacement caps can help minimize evaporation-related quantitation issues.
- Vortexing samples before analysis can improve sample homogeneity and reproducibility.