Tracer Technology Group

Perfluorocarbon Tracers

The mission of the tracer technology Group is to apply perfluorocarbon tracers (PFTs) to scientific and technical questions, to improve PFT methods, and to develop new applications for this unique tool.

PFTs have been widely used to study air movement and leak detection since the early 1980s. BNL has used PFTs to study atmospheric transport and dispersion on local, regional, and national scales. These studies have led to increased understanding of the movement of pollutants and other hazardous substances in the atmosphere and to improvement and validation of atmospheric transport models. These research programs have application to issues of critical national and global importance such as homeland security, air quality, and climate change. BNL has used PFTs for leak detection to study infiltration into Nuclear Power Plant Control rooms, the integrity of subsurface pipes, ducts and barriers.

PFTs are totally fluorinated cycloalkane compounds consisting of 4, 5, and six atom carbon rings. Because the fluorine-carbon bond is strong, with energies in the range of 450 to 530 kJ mol^-1, these molecules are very stable. They are not susceptible to oxidation in the atmosphere. The only important sink for perfluorocarbons is photolysis in the mesosphere. PFTs do not deplete stratospheric ozone. They are biologically benign and have been considered as blood substitutes and are used in eye surgery.

PFTs make good tracers because of their physical characteristics and because they are present in the atmosphere at low levels. Background concentrations are several parts in 10¹⁵ (parts per quadrillion by volume, ppqv) so the release of small amounts of PFT results in unambiguous signals. The large numbers of fluorine atoms and the structure of of these molecules cause them to have high electron affinities, approximately 3 eV. They are detectable at femtogram (10^-15) levels using an electron capture detector (ECD) or using negative ionization chemical ionization mass spectrometry (NICI-MS). Their relatively low vapor pressures allow PFTs to be concentrated on adsorbents so the sampling process can be used to increase the PFT signal. PFTs typically used as tracers are given in Table 1. The background levels of PFTs, current atmospheric burden, and estimated emission rates are given in Table 2.

Table 1: PFTs commonly used as tracers, acronyms, IUPAC names, chemical formulae, molecular weights, and boiling points.

Table 2: Current PFT background levels, estimated rates of increase, and estimated annual emissions. CO₂ data are presented for comparison.

Last Modified: June 18, 2008
Please forward all questions about this site to: Linda Satalino

One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.

Privacy and Security Notice  | Contact Web Services for help