Acquiring a Flame Atomic Absorption Spectrophotometer to Detect Base Cation Trends

This proposal requests funding for a flame atomic absorption spectrophotometer (Flame AAS) for use by the research group led by Project Director Kahl and collaborators at the University of Maine, Orono (UMaine). The group’s research focus is on Natural Resources and Environmental Quality.

UMaine has been involved in atmospheric deposition research for 25 years, including current projects to evaluate the 1990 Clean Air Act amendments. Recently, this research has focused on the decline in base cations (Ca, Mg, K, Na) in surface waters of northeastern North America as a leading explanation of the lack of ‘recovery’ from acidification. This effect has been documented most recently by the regionally-extensive EPA assessment led by Dr. John Stoddard (EPA) and Kahl. Although there are many projects that will benefit from a Flame AAS, research questions surrounding base cations are the main motivation for this proposal.

The decline in base cations in surface waters reflects a decline in cation export from forested watersheds. The potential implications of this change for soil chemistry are many, both for the forests and for the aquatic ecosystems associated with these forests. A Flame AAS will be an integral analytical component for this work in determining base cation concentrations. In particular, historical base cation data were collected using Flame AAS, so to obtain the best trend estimates, we compare our historical data directly with ongoing collections of cation data using Flame AAS. We are therefore in urgent need of replacing the outdated and failing Flame AAS that was acquired by the Mitchell Center 12 years ago (it was a reconditioned used unit at the time of purchase).