According to one possible picture of the Titan atmosphere interaction with Saturn's magnetosphere, newborn exospheric pickup ions may exhibit a marked asymmetry with respect to the corotation wake due to their large gyroradii in the local ~5 nT magnetic field. These finite gyroradius effects should persist until the ions are scattered by wave-particle interactions (a scale length that is presently unknown). To the extent that simple test-particle-like motion is maintained, the combination of the small (on the scale of most ion gyroradii) size of Titan and the small, steady local magnetic field at ~20 Saturn Radii provides a natural ion mass spectrometer configuration. The resulting spatial dispersion of the pickup ion trajectories can be used for both analyzing the composition of the Titan exosphere and determining the ionization rates of its various constituents. Possible evidence of this ion mass spectrometer effect may be visible as a magnetic field perturbation in the Voyager 1 Titan flyby data. ¿ American Geophysical Union 1996