We present early results from our project to investigate if there is a relationship between the mass-loss rates of AGB stars and the chemistry within the circumstellar envelopes that this process creates. We have obtained high spectral resolution (R > 60,000) observations with the Echelon Cross Echelle Spectrograph (EXES) aboard SOFIA of a small sample of C, M, and S-type AGB stars. The mass-loss rate of this sample ranges from 10-7 to 10-5 solar masses per year. We have focused on two spectral regions (7.5 & 13—14 μm) that allow us to study several molecules that are either exceedingly difficult to observe from the ground or have no permanent dipole moment.

{"references": ["Ag\u00fandez et al. 2020, A&A, 637, A59", "Fonfr\u00eda et al. 2019, A&A, 622, L14", "Fonfr\u00eda et al 2020, A&A, 643, L15"]}