Repetitive injection method: a tool for investigation of injection zone formation and its compression in microfluidic liquid chromatography.

•A repetitive injection method was developed to study wide injection zone generation and compression.•A spreadsheet was designed for the simulation of injection zone generation and their gradient compression.•The spreadsheet allows for the variation of multiple parameters, including injection volume, injection solvent strength, gradient delay, and gradient conditions.•Zone generation due to large volume injection was experimentally investigated in μLC.