Glycine identification in natural jarosites using laser desorption Fourier transform mass spectrometry: implications for the search for life on Mars.

The jarosite group minerals have received increasing attention since the discovery of jarosite on the martian surface by the Mars Exploration Rover Opportunity. Given that jarosite can incorporate foreign ions within its structure, we have investigated the use of jarosite as an indicator of aqueous and biological processes on Earth and Mars. The use of laser desorption Fourier transform mass spectrometry has revealed the presence of organic matter in several jarosite samples from various locations worldwide.

Direct LD-FTMS detection of mineral-associated PAHs and their influence on the detection of co-existing amino acids.

Polycyclic aromatic hydrocarbon (PAH) compounds and amino acids (AAs) are both ubiquitous throughout the universe and can be co-located in mineral matrices (e.g., meteorites); therefore, co-detection of PAHs and AAs associated with terrestrial and extra-terrestrial minerals is of interest.

Spatially-correlated mass spectrometric analysis of microbe--mineral interactions.

A new methodology for examining the interactions of microbes with heterogeneous minerals is presented. Imaging laser desorption Fourier transform mass spectrometry was used to examine the colonization patterns of Burkholderia vietnamiensis G4 (previously Burkholderia cepacia G4) on a heterogeneous basalt sample. Depth-profile imaging found that the bacterium preferentially colonized the plagioclase mineral phase within the basalt.

Dual-Label Radioisotope Method for Simultaneously Measuring Bacterial Production and Metabolism in Natural Waters.

Bacterial production and amino acid metabolism in aquatic systems can be estimated by simultaneous incubation of water samples with both tritiated methyl-thymidine and C-labeled amino acids. This dual-label method not only saves time, labor, and materials, but also allows determination of these two parameters in the same microbial subcommunity. Both organic carbon incorporation and respiration can be estimated.