Our group conducts research in two lab spaces, the Aquatic Biogeochemistry Lab and the Radiocarbon Lab.
The Aquatic Biogeochemistry Lab
This lab houses instrumentation for biogeochemical analyses of natural waters, including both freshwater and marine. We use a Lachat Quickchem Series 8500 Flow-Injection Autoanalyzer for measuring dissolved nutrients. We have the ability to analyze NO2/NO3, NH3, PO34-, and total dissolved N and P (TN and TP, respectively). From this we can also calculate the concentrations of dissolved organic N and P (DON and DOP, respectively). We also use a Shimadzu 5050 TOC analyzer for measurements of dissolved organic carbon (DOC). Other instrumentation includes a Shimadzu Model GC-8 gas chromatograph for analysis of methane and other lower molecular weight hydrocarbon gases.
The Radiocarbon Lab
This lab is a designated space for the analysis of natural abundance of stable and radioactive isotopes. We specialize in 14C and 13C extractions of both organic and inorganic forms of carbon from freshwater and marine samples. Dissolved organic carbon (DOC) is quantitatively oxidized to CO2 by high-energy UV oxidation. Particulate organic carbon (POC) and sediment organic carbon (SOC) is oxidized to CO2 by high-temperature sealed quartz tube combustion. Dissolved inorganic carbon (DIC) and solid-phase carbonates are acidified to CO2. Using specialized vacuum distillation lines, the CO2 derived from different sample types is cryogenically extracted and purified prior to 13C (by isotope ration mass spectrometry, IRMS) and/or 14C (by accelerator mass spectrometry, AMS) analyses. In conjunction with the OSU Stable Isotope Biogeochemistry Laboratory, solid-phase samples are also routinely analyzed by elemental analysis-IRMS (EA-IRMS) for both 13C and 15N.