Described is a mobile phase fitting having reduced corrosion and erosion. The fitting includes a coupling body, compression screw, compression member and gasket. The coupling body has a threaded bore at one end, a tapered cavity, a narrow bore and a fluid channel. The compression screw has an axial bore to receive a tube and a threaded outer surface in engagement with the threaded bore of the coupling body. The compression member is disposed in the tapered cavity and has an axial opening to pass the tube and a tapered surface to engage a surface of the tapered cavity. The gasket is disposed in the narrow bore and has one surface in contact with the first internal surface and has a parallel surface to receive an end face of the tube. Mobile phase flows along a path that includes the tube, an opening in the gasket and the fluid channel.