Remote spacecraft observations of Mars indicate a significant role of water and other volatiles in shaping the evolution of surface features and mineralogies. A likely source of these volatiles is degassing of the Martian mantle through volcanism. Martian meteorites are the only samples we currently have from Mars and their chemistry could potentially provide important constraints on the past volatile content and evolution of the martian mantle. Variations in the concentrations of volatile elements measured by SIMS in minerals of the Martian meteorites may shed light on volatile degassing processes, but could also reflect secondary processes such as diffusive re-equilibration. Isotopic analyses, coupled with concentration variations, may be used to differentiate between such processes, but there are analytical challenges with obtaining precise and accurate isotopic compositions. After calibrating for matrix effects, the light lithophile element (LLE) and fluorine (F) concentrations and isotopic compositions of pyroxene determined in situ in several Martian meteorites suggests that the primary magmatic signature of LLE and F zonation in Shergottite pyroxene has been disturbed by post-crystallization diffusive equilibration. Using relevant crystal-melt partition coefficients the F contents for Martian meteorite parental melts are ~910 and ~220 ppm. Estimates of the F content in the Shergottite and Nakhlite source regions are similar to that of mid-ocean ridge basalts (MORB) and ocean island basalts (OIB), respectively, here on Earth.