A core holder comprises a plurality of fluid flow lines, a housing, a core sleeve disposed within the housing, an end cap coupled to a first end of the core sleeve and a first end of the housing, and an injector assembly disposed within the housing and coupled to a second end of the core sleeve. The injector assembly comprises a plurality of fluid passages coupled to the plurality of fluid flow lines, and a chamber in fluid communication with the plurality of fluid passages and an interior of the sleeve.