Accurate mass tools for unknown analysis of pharmaceuticals, pesticides, and surfactants in surface and groundwater samples may be divided into four major groups. We review these four groups, with real-world examples from water samples, showing how developments and improvements to the tool box enhance the analysis and discovery of contaminants. The groups include, firstly, Hardware Tools, such as Auto-MS-MS, targeted MS-MS, All Ions, pseudo MS3rd, and accuracy and resolution examples. The second group is Software Tools, such as databases, MS-MS libraries, Kendrick mass tools, mass structure correlator, and forcing routines of the elemental calculator and isotope tools. The third group is Ion Chemistry Tools, such as adduct formation tools (H+, Na+, and NH4+, the rule of 5 mass units in surfactant analysis), fragmentation tools (diagnostic ion and family ions), and rules of ion fragmentation (N rule and odd and even electron ion rules). The last group and least developed, which may be one of the most promising areas for new tools for future studies, we call “Physical and Biochemical Tools”. This last group will be illustrated with examples of pharmaceuticals and pesticides found in surface and groundwater samples. Examples include using both natural biodegradation pathways (e.g. de-alkylation of triazines in soil, methylation/demethylation reactions in wastewater, and manmade degradation pathways (hydroxylation by UV treatment of drinking water) as a guide to discover new or related contaminants. Another example is the autocorrelation of pharmaceuticals in drinking water sources, i.e., if compound x is found in a database search, other drugs or metabolites may correlate and be present too (sulfamethoxazole/trimethoprim example, lamotrigine and its glucuronide). We euphemistically call the application of this last group, “thinking outside-the-tool box” because that is what is needed to advance this application. Lastly we will show how the iterative use of these four groups of tools may enhance the analytical power of accurate mass using UHPLC/QTOF-MS.

Developing and improving accurate mass tools for the analysis of unknowns in surface and groundwater samples

255th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.