We describe a procedure to obtain ultra high electron lifetime in liquid xenon by means of a commercial Oxisorb cartridge and the distillation of the liquid. An improved ICARUS-type purity monitor chamber is described as well as details of the purification process. No charge attenuation is observed over the drifting distance (6 cm) at electric fields ranging from 800 down to 5 V/cm. This implies a free electron lifetime of at least several milliseconds. Results on the drift velocity dependence on the temperature are also reported.