Analysis of the Ultra-Short-Chained Fluorocarboxylic Acids TFA and DFA in Various Water Samples (Drinking, Mineral, and Surface Water)

Trifluoroacetic acid (TFA) is found worldwide in salt and fresh water in its deprotonated form where it is very mobile and highly stable. TFA enters water bodies through many sources whether directly from industrial wastewater or as breakdown product of one of the countless substances that contain a CF3-group like pesticides, pharmaceuticals, or refrigerants. On the contrary, not much is known about the origin of difluoroacetic acid (DFA) in the aquatic environment where it was reported in several instances and was therefore also part of our method development for the analysis of ultra-short-chained fluorocarboxylic acids in water.

The analysis of TFA and DFA in water seems easy on first sight but becomes tricky when stepping away from LC-MS-grade water and looking into real water samples containing different concentrations of naturally occurring anions. The LC-MS/MS method was optimized by testing tap, mineral, and surface waters from different sources available to our demo lab in Wilmslow, UK. We aimed for 20 ng/L LOQ for both compounds with a direct injection of the water samples.

One other aspect in the analysis of TFA and DFA, especially when trying to reach LOQs in the lower ng/L range, are the severe contamination sources for the two compounds. We tested filter, pipette tips and vials to recommend material that is free of TFA and DFA blind values.

During the webinar the different steps of method development will be discussed. Feasibility, sensitivity, and robustness is demonstrated with results from various water samples

Presenter: Hannah Willmer (Senior application Chemist, Waters Corporation)

Hannah Willmer is an applications chemist in the European demo lab, based in Wilmslow, UK. Her main role focuses on application development work for the food and environmental sector.

With a background in bioanalysis supporting the pharmaceutical sector, Hannah further developed a passion for the food and environmental industry. She cultivated this enthusiasm in a contract organization for 6 years where she managed a team and developed methods for the analysis of food and supplements from nutritional testing to food safety compliance. She specialized within the pesticides and contaminants department with a focus on infant formula which brings its own challenges such as more stringent regulations and high throughput.

As a former research analyst and Waters client Hannah understands the importance of robust and reliable methods to Waters’ customers and strives to enhance the customers’ experience with the quality comprehensive solutions that are essential to meet the demands in modern testing.