Previously, I was under the impression that, when it came to distilled vs. DI, distilled water was more pure. So pure, being near or at 0 ppm, it
would bind with the minerals in your body, depleting them, and therefore is unsafe to drink... At 50 ppm, water ought to be plenty safe to drink,
right?
However, yesterday in my college gen chem lab course, my lab manager told us the opposite. Furthermore, we were provided with this table. When I asked
if price was why we were using DI instead of distilled (to add back volume to a boiled water sample) he said that, no, it was because the DI was more
pure. This is against everything I thought I learned about water purity, although it is reflected in the table.
Is the table accurate? Where would the 50ppm in distilled water come from? Wouldn't the act of distillation remove 100% of impurities except
volatiles? (not solids, so doesn't count towards the TDS ppm) Just can't figure out another way that impurities could make it through a distillation.
Are there exceptions for certain molecules?
On ResearchGate, someone said of double distillation, Quote: | "The problem with it is that since it is continuous distillation, some contaminants will come across with the water." | But what contaminants would do this, and how? Ride the vapor up to the condenser? |