Environmentally Persistent Free Radicals (EPFRs) are radical-particle systems present in airborne-particulate matter and other environmental solid samples. EPFRs, which are formed by reactions between transition metals and organic material, may affect respiratory and cardiac health.
Researchers in the LSU Superfund Research Center's Materials Core laboratory have developed a method to synthesize surrogate samples of EPFRs with controlled particle composition and precisely controlled radical concentration number (spins/gram of sample). Such samples can be used in laboratory studies of EPFRs.
The LSU Superfund Research Center can provide interested laboratories and research groups with surrogate samples for research purposes. Samples are based on a silica matrix with a single particle size of 0.2 microns and smaller. The table below provides a selection of transition metals and aromatic molecule precursor of the EPFR systems presently being synthesized.
| Metal System | Radical half-lifetime in air | Precursors |
| Cu(+2/+1) | Few hours | 1,2-dichlorobenzene (except Fe) |
| Fe (+3/+2) | ~1-3 days | 2-monochlorophenol |
| Ni(+2/+1) | ~3-4 days | Hydroquinone (low radical concentration) |
| Zn(+2/+1) | ~2 months | Catechol (low radical concentration) |
Contact Slawo Lomnicki for details or for more information.