After using an infusion extractor on my Mariner’s compass (infused), it no longer appears in my list of inventory items in the Mystic Forge, meaning I can no long attune it. This has also been discussed on a Reddit post here: https://www.reddit.com/r/Guildwars2/comments/3qano1/cant_upgrade_ascended_ring_to_attuned_version/
This post was not made by me.