Field ion emission from single sample droplets deposited from an aqueous solution of sucrose on bare 10μm W wires has been studied by combined optical microscopy and mass spectrometry. The experiments reveal molecular ion emission from an amorphous nearly solid or glassy state of the sample, having a loose structure with many cavities. This state is formed via the growth of field-enhancing protuberances from a viscous liquid state and the evaporation of solvent molecules from the surface of the protrusions. The temperature range of molecular ion emission is significantly below the melting point of sucrose. Observed changes in the ion energy distribution and intensity fluctuations are consistent with ion emission from transient glassy protuberances of low ionic conductivity. The desolvation of ions is explained by a cooperative mechanism of ion extraction from a molecularly rough surface. In this mechanism, successive ruptures of intermolecular bonds are accomplished by rearrangements of molecules in the surface upon the field stress. The principal features of the desolvation mechanism are suggested to be the same for most polar biochemicals forming a glassy state after evaporation of the solvent.