Described are a method and a system for diluting a sample at a location of injection in a liquid chromatography system. The method includes loading a sample into a first fluid channel, separating a flow of a mobile phase into a first flow in the first fluid channel and a second flow in a second fluid channel, and combining the sample that is displaced from the first fluid channel and the mobile phase exiting the second fluid channel at the location of injection into the system flow to thereby generate a diluted sample in the system flow. The dilution ratio of the diluted sample is responsive to the flow rates of the first and second flows. Advantageously, the flow rates can be changed by changing the flow restriction of one of the fluid channels. Thus providing the proper flow restriction enables a user to obtain a desired dilution ratio.