Abstract: The boundary entropy inequality problem of simplified chromatography equation was discussed by  using entropy flux pair and 
the viscosity vanishing method. Firstly, by judging whether the solutions of the initial value problem of the chromatography equation satisfied the boundary entropy inequality, we gave the interaction of the elementary waves on the boundary, and then gave the global solutions for the initial boundary value problem of the chromatography equation. Secondly,  the correctness of the theoretical analysis for the initial boundary value problem was verified by numerical simulation.

Key words: initial boundary value problem, entropy flux pair, wave interaction, chromatography equations, Dirac shock wave