The invention relates to a method and a kit for the isolation of phosphorylated peptides from complex mixtures using support materials having chelate ligands based on silica and alkaline elution buffers. In preferred embodiments, the method according to the invention enables the isolation of phosphopeptides from complex sample solutions with a reproducibly high yield and at the same time with high purity and it allows efficient ionisation and detection of the isolated phosphopeptides both by MALDI-TOF and also by ESI mass spectrometry without additional requisite method steps, such as, for example, chromatographic desalination of the sample.