If you are really serious about investigating possible substituents for performic or peracetic acid, there are a couple of articles to read before you start wasting energy:
- Organic Reactions Volume VII (1953). Daniel Swern, Chapter 7: Epoxidation and hydroxylation of ethylenic compounds with organic peracids, pp 379-433.
- The Chemistry of Functional Groups, Peroxides (1983). Edited by Saul Patai.
There is a good Chemical Reviews article on Rh's site as well. I don't think that citric acid would work well. I think there are quite somewhat intramolecular forces that stabilize the citric acid molecule.
Ave Hive, synthetisandi te salutant!