As reviewed recently, there are many sources of artefact peaks in chromatographic separations, for example gradient separations are particularly susceptible to artefacts due to contaminants in mobile phase or equipment.Such peaks due to contamination are relatively easy to identify by comparison with chromatograms of blank samples.A less frequently-discussed source of artefacts is degradation of the analyte occurring on the column during the chromatographic separation, where the chemical environment experienced during chromatography is necessary to cause degradation of the analyte (as opposed to the situation where the analyte is simply unstable in solution in the mobile phase).