Analysis of Perfluorinated Compounds in Drinking and Waste Water Using Sequential and Parallel Automated Solid Phase Extraction Using EPA Method 537.1

Challenges and Opportunities for Solid Phase Extraction
Oral Presentation

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


Contact Information: [email protected]; 617-393-2396


ABSTRACT

Perfluoralkylated compounds contain a perfluorinated or polyfluorinated carbon chain moiety such as F(CF2)n- or F(CF2)n-(C2H4)n. Recent years has seen increasing concern over the levels of these chemicals, e.g. (PFOS (perfluorosulfonate), PFOA (perfluoro-octanoicacid)) in the global environment because of their fate and adverse effects. PFOS is now subject to increasing levels of control in various countries. This study demonstrates the first automated sequential/parallel solid phase extraction system made specifically for PFC extraction and concentration in accordance with USEPA method 537.1. The system with polyethylene tubing and stainless steel components is designed to give low PFC background.

Method for one module of sequential/parallel system: the SPE system was loaded with PFC 500-mg cartridges that were each conditioned with 15 mL methanol and 40 mL water. Five 250-mL water samples were spiked with 25 L of 1 g/mL PFC standard solution. Samples were loaded onto the SPE system and passed across the cartridge under vacuum. After loading, bottles were rinsed with 25 mL water and loaded across the cartridge under negative pressure. The cartridges were dried using nitrogen until no residual water was present (~20 min). The cartridges were eluted with 25 mL methanol to collect the PFCs. Samples were analyzed with LC/MS.

Some of the results: PFBS 82% recovery, background 0.01 ng/L; PFPeA 100%, 0.03 ng/L; PFHxA 94%, 0.08 ng/L; PFOA 93%, 0.15 ng/L; PFOS 86%, 0.05 ng/L; PFDA 87%, 0.06 ng/L; PFDoA 86%, 0.03 ng/L.

Note that with this sequential/parallel system up to 6 modules can each run one sample at the same time and that up to five samples can be run on each module sequentially. This means up to 30 samples can be run completely unattended over a roughly 5 hour period. The automated sequential/parallel Solid Phase Extraction System for PFCs gives good recoveries and very low background.