What are the requirements for using the Alchemy Trainer Lorokeem ( https://www.wowhead.com/wotlk/npc=19052/lorokeem ) ?

Here's a pic of my trying to use him: https://i.imgur.com/wbH4qaK.png

My alch skill is 300/375 and my character is level 61. Why can't I use him as an alchemy trainer?