Soft cluster-induced desorption/ionization mass spectrometry: How soft is soft?

Desorption/ionization induced by neutral clusters (DINeC) is used as an ultrasoft desorption/ionization method for the analysis of fragile biomolecules by means of mass spectrometry (MS). As a test molecule, the glycopeptide vancomycin was measured with DINeC-MS, and resulting mass spectra were compared to the results obtained with electrospray ionization (ESI), matrix assisted laser desorption ionization, and time-of-flight secondary ion MS. Of the desorption-based techniques, DINeC spectra show the lowest abundance of fragments comparable to ESI spectra. The soft desorption nature of DINeC was further demonstrated when applied to MS analysis of teicoplanin.