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PFAS (Per- and poly-fluoroalkyl substances) are persistent, man-made organic compounds, widely found in the environment. Recent awareness has brought attention to the toxicity of these substances. The U.S. Food and Drug Administration (FDA) and the U.S. Environmental Protection Agency (EPA) have initiated actions against PFAS.
For determination of PFASs, liquid chromatography–mass spectrometry (LC-MS) is a commonly used technique. The new Ascentis® Express PFAS HPLC column, with its Fused-Core® technology and a particle size of 2.7 μm, delivers fast and high-resolution separations with excellent selectivity, peak shape, and necessary retention to perform in regulated methods.
The HPLC column of choice for PFAS analysis by LC-MS/(MS) is a C18 column based on fully porous silica particles (FPP) such as Ascentis® C18 and PurospherTM STAR RP-18 endcapped or on superficially porous silica particles (SPP) such as Ascentis® Express.
In contrast to ordinary FPP C18 columns Ascentis® Express PFAS columns are tested using a PFAS compound mixture. This ensures the full suitability of the column for PFAS analysis.
The contamination of PFAS compounds from the HPLC system and materials used in analytics is a concern. Therefore, it is recommended to use a delay column, which is placed before injection in the system set-up.
The highly retentive endcapped silane of the Ascentis® Express PFAS Delay column provides high retention of PFAS compounds across various mobile phase conditions and is used to delay background instrument PFAS contamination from interference with analyzed samples. For this reason, the Ascentis® Express PFAS Delay column is placed upstream of the sample injector and after the mixer.
The new Ascentis® Express PFAS HPLC column is designed for the separation of novel and legacy short chain and long chain PFAS compounds containing branched and linear isomers, whilst adhering to EPA methodology requirements. Furthermore, a specific PFAS delay column prevents background PFAS contamination from interfering with the sample results in quantitative LC-MS methods.
Key benefits of Ascentis® Express PFAS columns include:
• 2.7 μm Fused-Core® particle for reliable and high efficiency separations and lower column back pressure compared to sub-2 μm particles
• Excellent suitability for MS detection
• Application-related Lot analysis and single column performance testing
• Pressure limit: 600 bar
Conclusion
The new Ascentis® Express PFAS HPLC column allows the highly efficient separation of 33 PFAS compounds in 5 minutes, and it is equally adept at delaying PFAS contamination originating from the instrument by using the Ascentis® Express PFAS Delay column.
This application note demonstrates that the Fused-Core® technology of Ascentis® Express PFAS HPLC columns benefits PFAS analysis for fast, efficient, and rugged separations which are paramount to environmental analysis.
