A theoretical analysis was performed on the droplet asymmetric fission in e
lectrospray ionization process. The formulated model is able to predict the
diameter, charge and the percentage of charge at the Rayleigh charge limit
for both progeny droplets and residue parent droplet during each fission p
rocess based upon possible different numbers of progeny droplets generated
by the fission event. The evaporation time required for both the progeny dr
oplets and the residue parent droplet to become unstable after each fission
process was also calculated and compared. The results of these calculation
s showed that the evaporation time for the progeny droplets is more than an
order of magnitude less than that of the residue parent droplet, indicatin
g that the progeny droplets are the primary ion source for conventional ele
ctrospray ionization sources. (Int J Mass Spectrom 185/186/187 (1999) 97-10
5) (C) 1999 Elsevier Science B.V.