Tybalt has a nasty monster deck, so make sure you’ve got the biting frost weather card to neutralize his units as much as possible so they don’t overwhelm you. 1 is sold by the inkeeper at the Seven Cats Inn.1 is sold by the quartermaster at Crow’s Perch.1 is sold by the innkeeperess in the White Orchard Tavern at Woesong Bridge (or if you missed buying it from her, the merchant outside sells it as of Patch 1.04).There should be a alchemy logo near it, if not travel down the hill while going left. To get vitriol you must obtain the recipe from the a druid located in Skellige Isles near Gedyneith fast travel post it should be somewhere on the right.
Where to Get White Gull in The Witcher 3: Wild Hunt