I've not tried CXTC either, but they apparently give COAs out with the product, and state on there site it's 99.86 or 99.96 pure or something, can't remember for sure, and we don't know exactly how that's meassured either unless seeing the COA.
There are impurities in all the nics, including CXTC, from the leaf and extraction material, though with CXTC, they apparently don't use normal hexane or whatever methods, which is the advantage. I'm personally pretty sure that a nic like nicselect is purer than CXTC, but the taste of the leftover extraction material, even though it's under detection limit of 0.05%, still can impart a taste, like with nicselect and other nics, and if that's void in the CXTC, which I believe, then that's a big plus regardless of actual purity. I would rather have slightly more other alkaloids than leftover extraction material i.e. more tobacco taste than chemical/funkyness.
There are impurities in all the nics, including CXTC, from the leaf and extraction material, though with CXTC, they apparently don't use normal hexane or whatever methods, which is the advantage. I'm personally pretty sure that a nic like nicselect is purer than CXTC, but the taste of the leftover extraction material, even though it's under detection limit of 0.05%, still can impart a taste, like with nicselect and other nics, and if that's void in the CXTC, which I believe, then that's a big plus regardless of actual purity. I would rather have slightly more other alkaloids than leftover extraction material i.e. more tobacco taste than chemical/funkyness.