The Earth is struck by both negative and positively charged particles. As these particles interact with the Earth's magnetic field they become deflected. Do the magnetic poles of the Earth receive correspondingly higher doses of negative particles at one pole and positive at the other?
Since the cosmic rays come from all over and the magnetic field only applies force perpendicular to the direction of the particles' travel, there isn't any polar sorting in the sense of "positive to the north, negative to the south" or vice versa. Magnetic fields are related to electric fields, but they're not electric and don't cause electrical polarization.
However, the magnetic field does alter the path of incoming rays, causing them to spiral in to the poles; and depending on which pole and which charge are involved, the particles will spiral in opposite directions; negative charges will spiral clockwise in the same field that positive charges spiral counterclockwise. So there is a kind of sorting going on, in that sense.