| AVS 63rd International Symposium & Exhibition | |
| Applied Surface Science | Thursday Sessions |
| Session AS-ThA |
| Session: | Advances for Complicated Sample Preparation Strategies and Complex Systems |
| Presenter: | Amy Walker, University of Texas at Dallas |
| Authors: | A.V. Walker, University of Texas at Dallas L.D. Gelb, University of Texas at Dallas |
| Correspondent: | Click to Email |
Chemical imaging methods, including imaging mass spectrometry (MS), are becoming widely used for the analysis of a variety of samples from biological tissues to electronic devices. A significant barrier to wider adoption of imaging mass spectrometry is the presence of matrix effects which complicate quantitative analysis. Interactions between an analyte molecule and its surroundings (the “matrix”) can substantially alter both the yield and type of ions observed. These matrix effects result in both significant nonlinearity of signal intensity with concentration and changes in the characteristic spectrum of a given species with environment. We present progress towards the quantitative extraction of chemical concentration profiles, component spectra, sample topography, and other information from imaging mass spectrometry data in the presence of matrix effects. Our approach is based on maximum a posteriori (MAP) reconstruction against physically motivated models rather than statistical dimensionality-reduction techniques such as Principal Components Analysis. We demonstrate our methodology using several different samples as well as synthetic data sets. These include systems that demonstrate “weak” matrix effects, such as mixed self-assembled monolayers, and “strong” matrix effects such as those observed in ionic liquid matrix enhanced secondary ion mass spectrometry.