J. Dong, Y.H. Rezenom, K.K. Murray, Desorption electrospray ionization of aerosol particles, Rapid Commun Mass Spectrom. 21 (2007) 3995–4000. doi:10.1002/rcm.3294.


Schematic of the dry particle DESI setup
Schematic of the dry particle DESI setup. The electrospray emitter (a) was 4 mm away from the ion trap mass spectrometer (c). The angle between a and c was 60Β°. Nitrogen gas (N2) was used to assist the solvent (S) spray. Aerosol particles generated from a fluidized bed aerosol generator exited the tube (b). The angle between a and b was 90Β°.

We have applied desorption electrospray ionization to aerosol particles. Ions were formed from aerosols by merging suspended dry particles with an electrospray of solvent in a modified ion trap mass spectrometer. Dry aerosol particles were generated using a fluidized bed powder disperser and directed toward the inlet of the mass spectrometer. A nanospray source was used to create a spray of solvent droplets directed at the inlet and at a right angle with respect to the aerosol. Ions generated by the interaction of the particles and electrospray were transferred into the ion trap mass spectrometer. Using this method, pure samples of caffeine and erythromycin A were analyzed. In addition, commonly available food and drug powders including instant cocoa powder, artificial sweetener and ibuprofen were analyzed.