I have decided to do a a cyanotype experiment for my chemistry investiagtory project, this year in school. To do that, I need Ammonium Ferric Citrate, which my school lab does not stock. Also, local retailers don't have it. How can i prepare ammonium ferric citrate in my laboratory using common reagents. Some few common chemicals [like citric acid, if required might be available at a local chemicals retailer]. thanks a lot.