Just curious about how well the nicotine mixes. Have you done a test from say a 30ml bottle or larger of the bottom content of the bottle (if it's been sitting for a while) and the top bottle? Does this make sense?
ie: stick the syringe to the bottom, extract some juice test it and then take some from the top and test it.
Not gone that far, just made sure the contents were well shook before testing ..