[Zurück]

V. Weiss, K. Balantic, E. Pittenauer, G. Friedbacher, M. Marchetti-Deschmann, G. Allmaier:
"Nano electrospray differential mobility analysis (nES GEMMA instrumentation) based size-selection of liposomes and very-low density lipoprotein particles for offline hyphenation to MALDI MS";
Poster: 30th MassSpec-Forum Vienna, Vienna; 19.02.2019 - 20.02.2019; in: "Book of Abstracts", (2019), S. 55.

Gas-phase electrophoresis of single-charged analytes (nanoparticles) enables their separation according to the surface-dry particle size (Electrophoretic Mobility Diameter, EMD), which corresponds to the diameter of spherical shaped particles [1]. Employing a nano Electrospray Differential Mobility Analyzer (nES DMA), also known as nES Gas-phase Electrophoretic Mobility Molecular Analyzer (nES GEMMA), allows sizing/size-separation and determining of particle-number concentrations. Separations are based on a constant high laminar sheath flow and a tunable, orthogonal electric field enabling scanning of EMDs in the nanometer size range. Additionally, keeping the voltage constant, only nanoparticles of a given EMD pass the instrument and can be collected on corresponding supporting materials for subsequent nanoparticle analyses applying e.g. microscopic, immunologic or spectroscopic techniques (e.g. [2-3]). In our proof-of-concept study we now focused for the first time on mass spectrometric (MS) characterization of DMA size-selected material. We carried out size-selection of liposomes, vesicles consisting of a lipid bilayer and an aqueous lumen employed as carriers in e.g. pharmaceutic, cosmetic or nutritional applications. Gas-phase electrophoresis of liposomes has previously been demonstrated [4]. Particles of 85 nm EMD were collected on gold-coated silicon wafers. Subsequently, matrix was applied and Matrix-Assisted Laser Desorption / Ionization (MALDI) MS carried out. However, we not only focused on plain liposomes but also demonstrated the applicability of our approach for very low density lipoprotein particles (VLDL), a transporter of lipid metabolism. Our novel offline hyphenation of gas-phase electrophoresis (nES DMA also known as nES GEMMA) and MALDI-MS opens the avenue to size-select nanoparticles of complex nature prior to detailed MS analysis.
1. Kaufman SL, et al. Anal Chem. 1996; 68(11): 1895-904.
2. Havlik M, et al. Anal Chem. 2015; 87(17): 8657-64.
3. Wieland K, et al. Nano Res. 2019; 12(1): 197-203.
4. Weiss VU, et al. Analyst. 2016; 141(21) :6042-50.

GEMMA, gas-phase electrophoresis, nanoparticle, mass spectrometry