Improved Resolution for Paraquat and Diquat: Drinking Water Analysis Using the CORTECS UPLC HILIC Column

Diquat and paraquat are doubly charged quaternary ammonium herbicides. They are extensively used worldwide to control both crop and aquatic weeds. Both diquat and paraquat are too polar to be retained by reversed-phase liquid chromatography on C18 columns. This application demonstrates the UPLC separation using a CORTECS UPLC HILIC Column to significantly improve the retention and resolution of both analytes, allowing for detection down to 500 ppt by UV detection alone.