Characterization, Imaging and Quantitation of Small Molecules by Ambient Ionization Mass Spectrometry

For more than a century mass spectrometry has been a well-known technique in the field of chemical analytics. Its selectivity and sensitivity has made it popular in various fields. From analysis of pure organics, its use is still being explored in the analysis of biomolecules, either purified or direct from tissue sections. For analyzing these vast arrays of molecules, typically the front end is modulated depending upon the need of the user. For direct analysis of a sample of interest, ionization techniques such as DESI, PS, MALDI, etc are incorporated into the front of the mass spectrometer. In this work, the ambient ionization techniques, DESI-MS and PS-MS was modulated for characterization, imaging and quantification of small molecules. The use of DESI-MS and PS-MS in the field of forensics, microbiology and pharmaceutics is described. With the optimization of the front end modes, better sensitivity, selectively and robustness was ensured.