Sulfur was purified by plasma-chemical distillation at low pressure (0.1 Torr) under dynamic vacuum conditions. RF (40 MHz) non-equilibrium plasma discharge was used for initiation of chemical interactions. The carbon-containing impurities behavior was studied. The possible mechanism of their conversion has been discussed. The effectiveness of the suggested method has been compared with the 'traditional' distillation in terms of removal of heterophase impurities.