A liquid fuel cartridge unit for a gas turbine combustor includes a cartridge tip having an aft plate and a side wall circumscribing the aft plate. First injection ports are defined through the side wall, and second injection ports are defined through the side wall upstream of the first injection ports, relative to fuel flow through the cartridge tip. Nested conduits extend into the cartridge tip with the concentric conduits defining therebetween respective flow passages. The first injection ports are in fluid communication with a first flow passage, and the second injection ports are in fluid communication with a second flow passage. A method of assembling the liquid fuel cartridge unit is also provided.