Mixing smaller amounts of Amidol..

So my 8x10 gear has been rolling in over the past week, but still no holders. Ive been itching to try out my AZO for the first time, but all I have is 4x5 negs.. Id like to mix up a small amount of Amidol and run a few tests with my 4x5 negs. I dont want to mix a whole liter because I dont have much amidol, and I also dont have that many negs to run through it.. Can anyone recommend a way to mix say, 500ml (or half the common amount) of amidol? Thanks