Examining Non-Targeted Analysis LC-HRMS/MS Data - Tutorial 5: Fragmentation (MS/MS) Data

While accurate mass measurements are very helpful, especially when aided by examination of isotopic pattern, they fundamentally only provide information on what atoms, and how many, exist within a molecule. But the connectivity of those atoms can be extremely important, as structure informs function, toxicity, fate and transport in the environment, bioaccumulation, etc. One of the best techniques for determining structure, even of unknowns, is fragmentation (MS/MS). MS/MS consists of smashing analyte molecules (the molecule you are trying to annotate) with a neutral molecule (generally molecular Nitrogen (N2)). Think of shattering a molecule with a bullet, or ramming the molecule into another one; this shattering generally occurs at the weakest bonds. After the molecule is shattered, the pieces of the molecule can be used to determine the entire structure (think of having many lego pieces, and ideally an instruction manual for how these form the entire lego master piece; this instruction manual is your fragment rules or MS/MS library). Each fragment mass is measured. In this video we will discuss this process, as well as how we can use these fragments to determine structure, using examples from PFAS molecules. We will also discuss some of the most common fragments of PFAS and how these can be used to tell structure. MS/MS library matching, fragment screening, and predictive matching will be covered. Other links include: FluoroMatch Software and Support: https://innovativeomics.com/ Other tutorials (coming soon) ENTAILS NTA training material (coming soon) For predictive fragment matching, visit: https://cfmid3.wishartlab.com/ https://ipb-halle.github.io/MetFrag/