E-liquid – how many mg does it contain?
Per parcel, you’re allowed to import 150 ml of nicotine-containing e-liquid. But how do you actually measure its nicotine strength?
To do this, you should pick up the following from a pharmacy:
- Bromothymol blue in a dropper bottle as an indicator (approx. 10 ml)
- 0.05N hydrochloric acid (HCl) in a dropper bottle as a titrant (approx. 50 ml)
- Distilled water
- 2 x 10 ml measuring cylinders
- 1 ml syringe
- 2 ml syringe
You’ll also need gloves and, if necessary, a face mask and safety glasses so none of the liquid gets on you. Handle these chemicals with care, and of course keep them well out of reach of children.
First, draw up 1 ml of nicotine base with the small syringe and add it to the measuring cylinder. Next, add 4 drops of bromothymol blue to the measuring cylinder. Now top it up with distilled water to exactly 3 ml.
Next, add the dilute hydrochloric acid solution – but very, very slowly, because the acid is what lets you reach the endpoint. Before you add the hydrochloric acid, the liquid is deep blue. As you slowly add the hydrochloric acid, you’ll reach a point where the colour first changes to blue-green and then to yellow! Yellow is the endpoint – and you can use it to calculate the nicotine content!
You start with a 3 ml solution and an endpoint X – let’s say another 3 ml, for example. Then calculate it like this:
Total volume in the measuring cylinder = X
X minus 3 ml = Y
Multiply Y by the factor 8.111578 and you have the amount of nicotine. Please note: this method has a margin of error of +/- 0.8 mg, so the result may be that much lower or higher!
Some shops outside the country also sell ready-made test kits for home use! As you can see, if you really want to test it, it’s actually pretty straightforward!
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