Evaluation of SPE Formats for Improved Extraction and Quantification of Diquat and Paraquat in Drinking Water

Drinking Water
Oral Presentation

Prepared by E. Walters
Biotage, LLC, 10430 Harris Oaks Blvd., Suite C, Charlotte, NC, 28269, United States

Contact Information: [email protected]; 800-446-4752


Under the Safe Drinking Water Act (SDWA), the U.S. EPA regulates and monitors several contaminants in our drinking water supplies. Method 549.2 specifically addresses the extraction and quantification of diquat and paraquat, herbicide compounds that have been widely used around the globe and are known to be toxic to humans and animals. This method prescribes the use of a reversed phase C8 solid phase extraction (SPE) sorbent in either cartridge or disk-based formats. Due to the unique chemistry of this method, quantifying these analytes has proven to be challenging for laboratories. In this study, the evaluation of different C8 SPE formats provided further insight into the complex chemistry occurring within the extraction protocol. This work will present a robust extraction solution that allows laboratories to accurately measure diquat and paraquat as outlined in EPA method 549.2.