Results are presented from a series of lattice Monte Carlo simulations of the adsorption and desorption of polymer chains from semidilute solution onto a solid/liquid interface, where either the chains or the adsorbing surface contain chemical impurities. We compare these results with our previous results for chemically pure systems with regard to the growth, equilibrium structure, and dynamics of the adsorbed layers. Generally, the presence of impurities causes a reduction in the total adsorbance, but does not gravely affect the de Gennes-type self-similar grid found for the pure system. In one case, however, the impurities are found to increase the total adsorbance. We find some correspondence between the static chain characteristics for cases of impurities within the chains and impurities within the surface. There are, however, visible differences between the dynamics of the two cases, particularly in their growth and exchange kinetics. Dramatic changes in behavior are shown to arise when the chain impurities impede the ''reeling in'' motion of the chains onto the surface, altering the chains' relaxations. We compare our results with previous theoretical predictions for cases of random copolymer adsorption, and adsorption onto heterogeneous surfaces. (C) 1997 American Institute of Physics. [S0021-9606(97)50744-6].