Hello! Regarding your questions,
PurNic is the closest alternative by review to NicSelect in your case of being comfortable with that Nicotine brand. We no longer offer the NicSelect product for a variety of reasons and as you’ll see many vendors/competitors had to follow our footsteps as well with no longer offering that specific brand. Chemnovatic derives from Poland and is a great Nicotine product that provides consistent quality however, it’s higher priced. We keep the Chemnovatic product available for those customers that prefer this brand.
As for the 24mg, we unfortunately will no longer be carrying the product due to low sales and inventory space which will be used for new, upcoming products we have for the industry. We plan on keeping: 48mg, 100mg, and 250mg permanently available on our site. When diluting you are correct, it would ultimately introduce the Nicotine to oxygen however, if you keep the product in a freezer capped it should last nearly as long as if it wasn’t introduced to oxygen. I know this may make things more difficult on your end and we do apologize however, with the new inventory space available we have a lot in store for the industry!