In order to get insight in the transport of minorities in high-pressure plasmas we constructed with our software package PLASIMO a model with a two-fold structure. The first structure element describes the flow and temperature field of the main plasma constituent, mercury. The second calculates the LTE diffusion of the minority species. It is based on the set of chemical equilibrium equations, the constraints as imposed by Dalton's law, charge neutrality and the elemental mass conservation laws. The first results show that the transport of minority species can be described properly.