Can't help ya' much with nicotine. The UK has an upper limit, 72mg/ml if I remember right, and here in Hoosier-land any concentration is legal to purchase, but I usually buy 100mg/ml.
(Indiana if anyone wonders where to find Hoosier-land on an atlas. And it's a complicated story with many versions as to why we are called Hoosiers.)
I'm not certain any of the places I like to get nicotine from ship to the UK. I tend to get mine from Xtreme Vaping or Vapers Tek. Both of these will have more of a pink hue than brown when they start to oxidize. There is some really pure nicotine being produced in the UK, but I don't know which vendors over there are getting it and diluting it down for their countrymen.
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