title: Profiling an electrospray plume by laser-induced fluorescence and Fraunhofer diffraction combined to mass spectrometry: influence of size and composition of droplets on charge-state distributions of electrosprayed proteins.
abstract: We investigated how physico-chemical properties of charged droplets are affected by the electrospray process, using simultaneous in situ measurements by laser-induced fluorescence (LIF), Fraunhofer diffraction and mass spectrometry. For this purpose, we implemented a laser-induced-fluorescence profiling setup in conjunction with a fast, high-resolution particle sizing scheme on a modified Agilent Jet Stream electrospray source coupled to a single quadrupole mass analyser. The optical setup permits us to profile the solvent fractionation and the size of the droplets as they evaporate in an electrospray plume by measuring both the angular scattering pattern and emission spectra of a solvatochromic fluorescent dye. Mass spectra are recorded simultaneously. These mass spectrometry and optical spectroscopy investigations allow us to study the relation between the observed charge-state distributions of protein anions and physico-chemical properties of evaporating droplets in the spray plume. By mixing water with methanol, a refolding of cytochrome C is observed as the water percentage increases in the plume due to the preponderant evaporation of volatile methanol.
authors.affiliation: Université de Lyon, F-69622 Lyon, France.
authors.forename: Marion
authors.initials: M
authors.lastname: Girod
authors.forename: Xavier
authors.initials: X
authors.lastname: Dagany
authors.forename: Véronique
authors.initials: V
authors.lastname: Boutou
authors.forename: Michel
authors.initials: M
authors.lastname: Broyer
authors.forename: Rodolphe
authors.initials: R
authors.lastname: Antoine
authors.forename: Philippe
authors.initials: P
authors.lastname: Dugourd
authors.forename: Alex
authors.initials: A
authors.lastname: Mordehai
authors.forename: Craig
authors.initials: C
authors.lastname: Love
authors.forename: Mark
authors.initials: M
authors.lastname: Werlich
authors.forename: John
authors.initials: J
authors.lastname: Fjeldsted
authors.forename: George
authors.initials: G
authors.lastname: Stafford
mesh_terms: D045304:Cytochromes c / Q000737:chemistry; D005456:Fluorescent Dyes / Q000737:chemistry*; D007834:Lasers; D013058:Mass Spectrometry; D000432:Methanol / Q000737:chemistry; D010316:Particle Size; D011506:Proteins / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization; D055549:Volatile Organic Compounds / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D005456:Fluorescent Dyes; D011506:Proteins; D012997:Solvents; D055549:Volatile Organic Compounds; D014867:Water; D045304:Cytochromes c; D000432:Methanol