The invention includes an ion mobility spectrometer having a liquid filled drift chamber. The chamber has an ionization region partitioned from and an ion separation region by a reversible ion-migration block. An electrical field within the chamber allows ions to migrate toward the electrode collector. Passage of ions from the ionization region is triggered by reversing the block allowing ions to migrate into the ion separation region. The invention includes a method of ion mobility analysis in liquid phase. Ions are mobilized to migrate through a drift liquid and are detected at an end of a drift chamber. The invention also includes a method of generating ions in a sample. A sample containing molecules in a first solvent is introduced into a second solvent through a charged capillary where the electrically charged sample is electro-disperses to ionize the molecules.