In Phase 3 of WoW SoD, the Transmute Specialization was added along with the Alchemy Specialization. This means that transmuting an item gives a chance to get perks from that item.
Season of Discovery: All About Alchemy Specializations in SoD
The Transmute Specialization quest is located in the same location as the Alchemy Specialization quest in WoW SoD: Taranis. You need to go to Stormwheedle Port and look for new NPCs in the city. You can find Mixmaster Blix and Crimeon Leblade right next to each other around 67.22. While Blix has the quest to get the Alchemy Spec, Crimeon Leblade has the quest to give you the Xmute Spec. He will ask you for three Arcanite Bars in exchange for the spec, but you need to be at least Alchemy level 250. After the quest is completed, there will be no feedback from the game that you completed this quest, but you will have the mastery.
Related: How to Get the Phase 3 Epic Crafting Patterns in WoW SoD (Map)
Most people will probably buy Arcanite Bars from the Auction House, but you can also buy the items yourself if you want to take the trouble and save some gold. Arcanite Bars is a recipe that requires Alchemy level 275 and a Philosopher's Stone. The recipe can be learned from Alchemist Pestlezugg in Gadgetzan (51,27), and it requires an Arcane Crystal and a Thorium Bar to craft one Arcanite Bar, and the cooldown to craft one is about 2 days.
