Ambient ionization for methane quantification in simulated Martian atmosphere using miniature inductively coupled plasmas

The fundamental importance of understanding the origins of life has encouraged searching for extra-terrestrial organic molecules. Methane (CH 4 ) is the simplest organic molecule and has been sought on Mars for many years 1 . Additionally, the recent developments in ambient ionization techniques enable the ionization of samples in their native environment, without sample preparation or separation, providing sensitive, selective, rapid, direct, and high throughput analysis technique for a wide range of compounds 2 . Interestingly, intrinsic conditions of the Martian atmosphere provide favorable conditions for the formation of plasmas at ambient conditions. The Martian atmosphere consists of 95.32% carbon dioxide, 2.7% nitrogen, 1.6% argon, and trace amounts of other constituents such as oxygen, carbon mono oxide, water vapor and methane. The atmospheric pressure on Mars varies from around ∼0.2 Torr on Olympus Mons's peak to over ∼8.7 Torr in the depths of Hellas Planitia, with a mean surface level pressure of ∼4.5 Torr.