- Sample preparations for aqueous samples are performed using automated solid-phase extraction (SPE) techniques utilizing both polystyrene divinylbenzene (SDVB) media for EPA 537.1 or Weak Anion Exchange (WAX) SPE cartridges for expanded target PFAS lists. York employs Horizon Technologies/Biotage Smart Prep II automated SPE systems for aqueous extractions. This system was designed to be PFAS free to minimize background.
- Extract Concentration- Extracts are concentrated to dryness or small volumes (depending upon the methods) using an N-EVAP nitrogen system-Organomation Model 112. This system allows for up to 24 extracts to be automatically evaporated each with its own nitrogen flow control to minimize evaporative losses. All nitrogen delivery components are non-PTFE to again minimize PFAS background.
The analysis systems employed by York represent the latest available technology for the analysis of PFAS and related molecules. The systems are comprised of High-Pressure Liquid Chromatography (HPLC) interfaced to Agilent Triple Quadrupole (QQQ) MS/MS system.
The HPLC system is an Agilent Model 1260 Infinity II system retrofit with non-PTFE components to minimize PFAS background contribution. The HPLC system is interfaced
using the Agilent Jet Stream Electrospray interface (AJS-ESI) to an Agilent Model 6470AAR Triple Quadrupole (QQQ) MS/MS system using Mass Hunter B.09 software.
This system yields reporting limits (verified LOQ) of approximately 2.0 ng/L for aqueous samples and 1.0 ug/kg for soils.
As regulations unfold and possibly driven to lower levels, York is positioned to meet these needs. The system employed by York allows for a field upgrade to retrofit the 6470AAR to achieve 5-7 times more sensitivity than the current systems report. This option is important to staying ahead of the dynamic applications for PFAS.