The injection of an aluminium pellet into the plasma of T-10 was recorded by the surface analysis station WASA. The injected material was deposited only behind the lower slit of the probe. This asymmetry is explained by an × rotation of the plasma column and by the assumption that aluminium hits the probe in an ionized state. Estimations of the amount of injected aluminium reaching the WASA probe agree with the experimental results. By contrast, iron,chromium and nickel were deposited behind all four slits, which can only be explained by assuming that most of the intrinsic impurities hit the probe in a neutral state. In addition, the results of the experiment indicate that the gross particle confinement time is smaller than 90 ms. This is considerably shorter than the 150 ms obtained from the relaxation of the soft-X-ray signal.