Analysis of Perfluorinated Compounds in Water Using Automated Solid Phase Extraction

Characterization of Polyfluoroalkyl Substances in the Environment
Oral Presentation

Prepared by R. Addink
Fluid Management Systems, 580 Pleasant St, Watertown, MA, 02472, United States


Contact Information: raddink@fms-inc.com; 617-393-2396


ABSTRACT

Perfluoralkylated substances is a general term used to describe substances which are largely comprised of, or contain a perfluorinated or polyfluorinated carbon chain moiety of, F(CF2)n- / F(CF2)n-(C2H4)n . PFOS and other perfluorinated compounds are widely used in industrial and consumer applications including stain-resistant coatings for textiles, leather, and carpets, grease-proof coatings for paper products approved for food contact, firefighting foams, mining and oil well surfactants, floor polishes, and insecticide formulations. In recent years, there has been increasing concern over levels of perfluorinated and polyfluorinated chemicals, such as PFOS (perfluorosulfonate) and PFOA (perfluoro-octanoicacid), in the global environment and their fate and possible adverse effects in the environment.

This study demonstrates the first automated solid phase extraction system made specifically for PFC extraction and concentration. Especially effective at reducing background contamination, extraction and concentration of aqueous samples takes less than two hours.

500 mL water samples were spiked with 25 uL of a 1 ug/mL PFC standard solution. Samples were then loaded onto the PFC SPE system and passed across an HLB Plus 225 mg cartridge under -12 psi vacuum. After loading, bottles were rinsed with 25 mL of water and loaded onto the cartridge under negative pressure. The cartridges were dried using nitrogen until no residual water was present, and then subsequently eluted with methanol. The extracts were concentrated to 500 uL, after which internal standard was added. The samples were diluted to a final volume of 1 mL for LC/MS analysis.

Recoveries of spiked standards varied between 75-125% for a total of fourteen different PFCs. Background concentrations varied from 0.01 ng/L for PFPeA and PFDoA to 0.2 ng/L for PFOA. The SPE system for PFCs produced reliable, reproducible results for PFCs in water. The system has very low background PFC allowing for analysis of samples without significant interference.