Cyclodextrin and malto-dextrose collision cross sections determined in a drift tube ion mobility mass spectrometer using nitrogen bath gas.

In this study, we have evaluated a low field limit drift tube ion mobility device for ion mobility-mass spectrometry (IM-MS) measurements that uses nitrogen as a bath gas with electrospray ionization on a modified Q-TOF instrument. We have determined reduced mobility (K0) and collision cross section (CCS) values for a group of analyte ions that have been characterized previously in other drift tube IM-MS instruments. Our determinations of CCS for this set of ions as well as for standards are in agreement with published values.

Conformational ordering of biomolecules in the gas phase: nitrogen collision cross sections measured on a prototype high resolution drift tube ion mobility-mass spectrometer.

Ion mobility-mass spectrometry measurements which describe the gas-phase scaling of molecular size and mass are of both fundamental and pragmatic utility. Fundamentally, such measurements expand our understanding of intrinsic intramolecular folding forces in the absence of solvent. Practically, reproducible transport properties, such as gas-phase collision cross-section (CCS), are analytically useful metrics for identification and characterization purposes.

Basic vapor exposure for tuning the charge state distribution of proteins in negative electrospray ionization: elucidation of mechanisms by fluorescence spectroscopy.

Manipulation for simplifying or increasing the observed charge state distributions of proteins can be highly desirable in mass spectrometry experiments. In the present work, we implemented a vapor introduction technique to an Agilent Jet Stream ESI (Agilent Technologies, Santa Clara, CA, USA) source. An apparatus was designed to allow for the enrichment of the nitrogen sheath gas with basic vapors.

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.

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.