I make it about 0.36 mg/mL (assuming a UK gallon).
Ah, but you used a calculator - that's cheating
hmmmm... 0.29... 0.36... What's it about those numbers?
Numbers - they make the world go round. But pick at the frayed edges of coincidence, and you may find that "there be dragons!"
Now you mention it, the coincidence of slightly less than 0.2% deviation between test result and target equates curiously (and causes unsettling resonances in some of the more distant corridors of my mind,) with the 0.2% gap between the non-aqueous titration assay of the USP nicotine (99.8%) and 100%.
I think I'll mix the next batch to 54.1mg/ml to compensate (you may have noticed I'm a perfectionist - if every production bottle of my juice isn't of a standard high enough to calibrate tests by, then it's not good enough for me.
I'll bet the red label mess is all Nick's fault.![]()
In my quest to take over the world one lungful at a time, I unleashed my nanobot minions on an unsuspecting world to sabotage the competition - Mwaahaahaa!

(For the humor impaired in our audience, FYI: that was definitely a joke)
ditto (except for the taking over the world bit. And the nanobot minions obviously