What does water distillation mean in practice?
The process separates water from most non-volatile salts, but some volatile compounds may pass with the steam without adequate pre-separation.
When does it matter?
The purity of the distillate also depends on the material of the apparatus, the rejection of the first fraction and the hygiene of the receiving tank.
Which solutions are related to it?
Proper still design, conductivity control and clean storage are used to reduce secondary contamination.