Isotope Geochemistry

The geochemistry section conducts research using isotopes along with other chemical and geological parameters to help resolve environmental problems and to provide high-quality isotope analysis services.On-going research projects, include studying global climate change, age dating of groundwater, monitoring of landfill contamination, identifying different sources of chloride contamination, and deciphering the origin and fate of nitrate in surface and groundwater. Isotopic analyses are used for a wide variety of applications.

Some examples of isotopic geochemical applications include the use of radiocarbon analyses to determine the age of geological deposits left by the last glacial period and to date archeological artifacts. Tritium and radiocarbon analyses have been used to determine the age of our groundwater supplies and how well they are protected from surface contamination.

Radiocarbon and stable isotopes also have been used to study past environments and paleoclimates of Illinois. A combination of isotope analyses have been used to identify landfill gases and leachate and determine the sources of excess methane and carbon dioxide found in soils and basements. Nitrogen and oxygen isotopes have been used to identify source of elevated nitrate concentration in natural water and to study the extent of denitrification. Sulfur isotopes have been used to help determine sources of sulfate in groundwater.

Our service capabilities include radiocarbon (14C) dating, low-level tritium (3H) analysis and, isotopic analyses of carbon (13C/12C), oxygen (18O/16O), hydrogen (D/H), nitrogen (15N/14N), and sulfur (34S/32S). The applications of isotope analyses are continuously growing and helping scientists to better understand our environment and find answers to problems where other chemical and physical analyses alone do not yield enough information for definitive solutions.