Use of an acoustic wave in a chromatography system

A system for using an acoustic wave in a chromatography system, wherein the system comprises a surface acoustic wave assembly, wherein the surface acoustic wave assembly comprises

• a sender unit comprising a sender transducer for sending an acoustic wave and a detection unit for detecting the acoustic wave,
• a substrate configured for propagation of the acoustic wave,
• wherein the sender transducer is connected to the substrate,
• wherein the substrate comprises a substrate section for propagation of the wave from the sender transducer, wherein this substrate section comprises a substrate surface,
• wherein the surface acoustic wave assembly further comprises at least a first channel for conducting solvent with a sample and a second channel for conducting solvent without the sample, wherein the solvent without the sample is used as a reference for a differential measurement, wherein the first and second channels are partly defined by the substrate surface.