Ambient MS also allows label-free detection of compounds and gives unique insights into temporal changes and tissue architecture in two and three dimensions. Compounds studied range from natural products (e.g., neurotransmitters, metabolites, organic acids, polyamines, sugars, lipids, and peptides) to xenobiotics (e.g., pharmaceuticals), dyes, polymers, explosives, and toxins.
This critical review covers analytical trends in ambient MS. Our discussions primarily touch on the mechanisms of sampling and the bioanalytical implications for in situ and in vivo experiments. We pay special attention to lateral imaging, depth profiling, and three-dimensional-MS imaging, all while working under atmospheric conditions. Our closing remarks highlight some of the present analytical challenges and developmental opportunities in this field.