Mass Spec Imaging On Granite Surfaces

Chemists suspect that mineral surfaces helped catalyze the reactions leading to the first biological molecules. But they haven’t had the right tools to examine what role the heterogeneity of the mineral surface might have played. Imaging mass spectrometry with desorption electrospray ionization (DESI) might be the tool they’ve been waiting for. Facundo M. Fernández of Georgia Tech and coworkers at the virtual Center for Chemical Evolution used DESI imaging to study the thermal decomposition of formamide on granite (Anal. Chem., DOI: 10.1021/ac303202n). This reaction is a model for prebiotic formation of purines, which are building blocks for biological polymers such as RNA. The team imaged reaction products on smooth granite surfaces to study the effects of local mineral environment on the reaction. Granite is a mixture of minerals, including quartz, mica, and feldspar. In DESI images, the abundance of purines correlated with the composition of the underlying granite. Because they used commercially available instruments, Fernández and coworkers expect that other scientists will be able to investigate how this and other reactions on mineral surfaces behave under various conditions.