Aunt Jemima - none listed. Love me some Sodium Hexametaphosphate on my breakfast, though.
Vermont Maid - none listed. To paraphrase one of my favorite Simpsons exchanges: "The syrup contains sodium benzoate!" "That's good!" "No, that's bad."
Mrs. Butterworths - none listed.
Log Cabin - actually lists "pure maple syrup" as the fifth ingredient. It's the fifth ingredient in my syrup as well, but so are the first four.