Date: 21-SEPTMBER-2021 Last Updated: 10-SEPTEMBER-2026
Introduction
Per- and polyfluoroalkyl substances (PFAS) are routinely measured at extremely low concentrations using highly sensitive analytical techniques such as LC-MS/MS and, in some cases, GC-MS. At these trace levels, seemingly minor sources of contamination can affect analytical accuracy, increase background signals, or complicate data interpretation. For this reason, careful selection of sample containers, autosampler vials, caps, inserts, and laboratory consumables is an important part of PFAS method development and routine analysis.
Why Container Selection Matters in PFAS Analysis
PFAS compounds are widely associated with industrial materials, manufacturing processes, coatings, and various laboratory products. As analytical detection limits continue to improve, the potential contribution of background contamination from sample-contact surfaces becomes an increasingly important consideration. Potential effects include:
- Elevated background signals
- Increased analytical uncertainty
- False positives
- Variable quantitation
- Reduced method sensitivity
To minimize these risks, laboratories often evaluate every sample-contact material used throughout the analytical workflow.
RSA-Pro X™ Product Considerations
RSA-Pro X™ vials and inserts utilize a specialized hydrophobic surface treatment designed to improve recovery of proteins, peptides, enzymes, and other adsorption-sensitive compounds. While this technology provides significant benefits for many chromatography applications, it is not intended for PFAS testing workflows.
During the surface modification process, materials may be exposed to substances that are not considered suitable for ultra-trace PFAS analysis. As a result, RSA-Pro X™ products are not recommended for PFAS testing applications. This recommendation applies to:
- RSA-Pro X™ autosampler vials
- RSA-Pro X™ vial inserts
- RSA-Pro X™ surface-treated glass products
For most conventional HPLC, UHPLC, LC-MS, and bioanalytical applications, these considerations are not typically relevant. However, PFAS analysis requires a more restrictive approach to material selection.
Recommended Sample Collection Containers
For field sampling and sample collection, laboratories commonly use containers manufactured from:
- High-density polyethylene (HDPE)
- Polypropylene
Associated closures are typically:
- HDPE caps
- Polypropylene caps
These materials are frequently selected because they help reduce the likelihood of introducing PFAS-related background contamination during collection, storage, and transport.
Recommended Autosampler Vials for PFAS Work
For laboratory analysis, polypropylene LC-MS autosampler vials are commonly used in PFAS workflows. Potential benefits include:
- Reduced risk of PFAS-related background contributions
- Excellent compatibility with LC-MS methods
- Suitability for trace-level analysis
- Good analyte recovery characteristics
Proper vial selection is an important component of PFAS method performance and data quality.
Solvent Considerations
PFAS standards and samples are often prepared using solvent systems that promote analyte stability and consistent recovery. A commonly used preparation solvent consists of: 50% Methanol / 50% Water. This solvent composition is widely used for PFAS sample preparation and standard solution handling.
Cap and Closure Recommendations
Caps and septa can also influence analytical performance. Repeated puncturing of a vial closure may increase the potential for:
- Evaporation
- Concentration changes
- Sample variability
- Reduced quantitative precision
To help maintain sample integrity:
- Replace punctured closures when appropriate.
- Minimize repeated punctures whenever possible.
- Use properly sealed replacement caps.
- Reduce sample exposure during handling and storage.
These practices can help improve reproducibility and analytical reliability.
Sample Preparation Best Practices
Prior to analysis, sample homogenization is generally recommended. Vortex mixing may help:
- Improve sample uniformity
- Redisperse settled materials
- Improve injection-to-injection consistency
This may be particularly useful for samples stored for extended periods before analysis.
Recommended PFAS Workflow Materials
For PFAS testing applications:
Recommended
- Polypropylene autosampler vials
- Polypropylene sample containers
- HDPE sample containers
- HDPE closures
- Polypropylene closures
Not Recommended
- RSA-Pro X™ vials
- RSA-Pro X™ inserts
- RSA-Pro X™ surface-treated glass products
Choosing appropriate materials can help minimize potential analytical interference and support reliable method performance.
Additional Information
Conclusion
PFAS analysis requires careful control of all sample-contact materials due to the extremely low concentrations commonly measured by modern analytical methods. Because of the specialized surface-treatment process used in RSA-Pro X™ products, these vials and inserts are not recommended for PFAS testing. For PFAS workflows, polypropylene and HDPE materials are generally preferred for sample collection, storage, and laboratory analysis to help minimize the risk of contamination and maintain analytical confidence.