Digital subtraction chromatography: an LC-technique to reduce disturbing peaks in bioanalysis

A method of reducing disturbing peaks in LC-chromatograms is described. The technique, here called digital subtraction chromatography (DSCh), makes use of the new generation of integrating chromatographic data processors. These processors are able to store the LC-detector signal and then subtract one chromatogram from another with the resulting chromatogram reintegrated and reprinted. The possibility of getting a useful chromatogram by subtracting a zero sample chromatogram from a sample with disturbing peaks is demonstrated. The theoretical background of the method is given together with a discussion of the optimisation of the chromatographic conditions. A bioanalytical application is given.