Nanoparticles are widely used in many fields of our lives including pharmaceutics as well as food technology, electronics, optics or cosmetics. For the characterization of nanoparticles microscopy based methods like transmission electron microscopy (TEM) can be applied. Another method which provides information about the nanoparticle size distribution receiving increasing attention is gas phase electrophoretic mobility molecular analysis (GEMMA). GEMMA separates single-charged analytes after they have been transmitted to the gas phase according to their electrophoretic mobility (EM) diameter. At standard conditions, analytes are fed continuously (in steady state) to a fused silica capillary, aerosol is generated at the tip of this capillary in the electrospray (ES) unit of the instrument due to applied pressure, voltage as well as a mixed air / CO2 sheath flow. Aerosol droplets are dried and at the same time charge reduction in a bipolar atmosphere occurs. All non-volatile components of a given droplet aggregate to a single particle upon drying. Therefore, for complex samples, e.g. samples with a high salt content, the detection of individual analytes without salt aggregates on the surface of molecules is not possible: Corresponding EM diameters of analytes detected in GEMMA appear higher. In this work the additional electrophoretic separation of analytes in the liquid phase of the nano ES capillary of a standard, commercially available GEMMA instrument was developed. This additional electrophoretic separation of analytes in the liquid phase was demonstrated (proof of principle of operation) via two standard proteins, BSA and IgG. Furthermore, on-line desalting of these analytes could be shown. The new method was also applied for the analysis of biological nanoobjects (e.g. vaults or functional protein complexes). The separation of vault artifacts and vsvg-MVP vaults was demonstrated.