Separation and Identification of Basic Dendrimers Using Capillary Electrophoresis On-line Coupled to a Sector Mass Spectrometer

The on-line coupling of capillary electrophoresis (CE) with a sector mass spectrometer via an electrospray ionization (ESI) source has been used to separate and identify polydisperse dendrimeric diaminobutane (DAB)-based polynitriles. A sample of the corresponding second generation has been analysed and revealed to be a complex mixture of the product, DAB-dendr-(CN)8 accompanied by several by-products. The capillary electrophoresis/mass spectrometry (CE/MS) data, including the reconstructed-ion current, the mass spectra and the UV-trace, provided fast and detailed information concerning the heterogeneity of the sample. The respective ESI mass spectra are dominated by the [M+H]+, [2M+H]+ and/or [M+2H]2+ peaks. The mass resolution of the sector mass spectrometer requiring m/Δm=2000, easily allowed signals of doubly charged ions to be assigned. CE/MS proved to be a promising tool with regard to the efficient analysis of basic dendrimers.