A mixture of [Emim][EtSO4]-HAN is a potential propellant suitable in a multi-mode chemical-electric microtube-electrospray micropropulsion system. This paper reports experimental mass spectrum results for this liquid when electrosprayed in a 50 μm capillary emitter. Mass spectra from 0-600 amu were obtained over a variety of angles and flow rates from 2 pL/sec to 3 nL/sec in both cation and anion extraction mode. Effects of flow rate and angular orientation on the spectra agree well with literature. Results show at least three of the four monomer species are emitted, along with numerous other species, some of which have been identified. Results also show, for the first time, emission of both proton-transferred covalent species paired with both ionic species for HAN. Also, because the liquid is a mixture, swapping of anions and cations between constituents is observed. This swapping is most evident in anion mode, where numerous forms of HAN ([HNO3], 2[HNO3], 2[HA-H], and [HAN]) appear in the spectra attached with [EtSO4]-. Numerous peaks in the spectra remain unidentified, but are speculated to be impurities and fragments.