Fig. 3.

Schematic of solute migration in capillary zone electrophoresis (CZE)-MS under positive polarity. Note that the organic cations migrate fastest because they travel to the cathodic end (MS end), which is the same direction as the EOF travel. Neutrals travel at the same velocity as the EOF velocity and are not separated from one another. Organic anions migrate slowest because they are attracted to the positive end of the anode but are eventually pulled by the EOF toward the MS detector. The separation capillary is inserted through a stainless-steel needle and the sheath liquid and drying gas flows through the two outer tubes of the nebulizer and mixes with the CE effluent at the separation capillary tip to assist electrospray ionization (ESI).