Gas Mixtures:
Colibri > Vector >Power
Coibri is the most pure in terms of n-butane %. Vector after that, and Power is low grade Vector. Never use Ronsin or other cheap gases as they are not scent-free (aka added toxins).
You can always do a mirror test, meaning spray a few seconds of gas on a mirror. Every canned gas mixture (intended use as lighter refill) leaves a residue on the mirror, mostly made of paraffin waxes that are added to the gas mixtures to keep the torches lubricated internally. The only pure gas (no paraffin wax added and acutally 100% butane) is n-butane from AirGas, but you have to make sure to get the unscented kind. Many gas mixtures have scent added for safety, called mercaptans, they smell like sulfur usually.