I am assuming I would use the test kit on my nicotine I have purchased? Considering the cost of these kits ($10-$12 a test) it would seem the most useful and effective. But that is why I am asking. The nicotine I use is from MFS and is 100mg strength with a 100% VG base. I always say that it is better to ask then to never as at all. And if you see cheaper test kits out there, feel free to share the link or give me the name. Thanks again as always.