Droplets shrinking

Wortmann, A., Kistler-Momotova, A., Zenobi, R., Heine, M.C., Wilhelm, O., Pratsi-nis, S.E. (2007) Shrinking Droplets in Electrospray Ionization and Their Influence on Chemical Equilibria. J. Am. Soc. Mass Spectrom. 18 385-393. 

Letter D in Figure 8.9 refers to the droplet desolvation process. Besides the competitive ionization process inherent to ESI and the effect of different solvent compositions on ionization efficiency, it is also feasible to conjecture that the shrinking droplet may impart a concentration gradient which could cause a shift in the equihbria of interest. However, prior hypotheses and recent evidence suggest that if the host-guest association is kinetically stable on the time scale of the ESI process (psec - msec), then a reliable snapshot of the solution phase equilibrium may be obtained [10,42]. Additional studies in this area may shed more light on the system dependence of this potentially deleterious effect. 

If the charged droplets from any electrospraying process evaporate sufficiently rapidly, they may undergo further disruption and division after the initial break-up, since the shrinking droplets (both parent and daughter droplets) will repeatedly attain the threshold charge for electrostatic Rayleigh... 

---