VE can stand for “accounting unit,” “undercover investigator,” or even “Venezuela,” but today we mean demineralized water. The production of deionized water is based on the ion exchange process; sometimes it is also conceptually equated with distilled water, even though this is actually based on distillation. The quality of deionized water is regulated, for example, in ISO standard 3696; therefore, at 25°C, it must have a conductivity lower than 0.1 µS/cm.