Addressing PFAS Contamination: Troubleshooting Common Contamination and Instrumentation Problems

Drinking Water
Poster Presentation

Prepared by A. Adams, H. Libao, A. Ahn, M. Nguyen, P. Parmar, C. Carroll, T. Perez
Orange County Water District, 18700 Ward Street, Fountain Valley, California, 92708, United States


Contact Information: [email protected]; 714-378-8215

ABSTRACT

Due to the widespread presence of PFAS throughout the country and with many states lowering detection limits and proposing Maximum Contaminant Level’s (MCLs) in the low ng/L range, accurately performing PFAS analyses while minimizing the impact of background contamination is becoming even more important and challenging. The Orange County Water District (OCWD) laboratory has been analyzing PFAS compounds for over a decade, beginning with EPA 537 during UCMR 3. Since then, the rapidly increasing demand for PFAS data has resulted in new challenges for the OCWD laboratory such as increased sample frequency and lower detection levels, resulting in more detectable PFAS contamination during sample analysis. Failure to effectively manage these issues can lead to re-analysis, re-extractions, or re-sampling due to contamination above one-third of the reporting limit of 2 ng/L. OCWD has identified many potential sources of contamination from various parts of the extraction process such as cartridges, solvents, and centrifuge tube contamination due to vendor quality issues. In tackling these issues, OCWD has resorted to new practices such as lot testing new consumables for contamination or other issues prior to the bulk purchase of the lot. OCWD also performs routine preventative maintenance on our automated extraction systems, manual SPE manifolds, and LC-MS/MS instruments. These practices have helped to significantly reduce the amount of re-analysis, re-extractions, and system downtime in our laboratory.