For a detailed description of the instrumentation in the UMass Biogeochemistry laboratory, please click here to view the lab website.
HPLC-MS (High Performance Liquid Chromatography – Mass Spectrometry). HPLC-MS is used to analyze larger and more polar compounds than can be analyzed by GC-MS techniques. Specifically, I use this technique to analyze glycerol dialkyl glycerol tetraethers (GDGTs). What are GDGTs and why are they important? GDGTs are membrane lipids biosynthesized by Thaumarchaeota (domain Archaea). A method for determining past sea surface temperature (called TEX86) is based on GDGTs (Schouten et al., 2002) – basically, with increasing sea surface temperature, these organisms biosynthesize GDGTs with an increasing number of cyclopentane rings. TEX86 also works for determining past surface temperatures in some, but not all, lakes (read more about the application of TEX86 to lakes)
GC-FID (Gas Chromatography with Flame Ionization Detection). GC-FID is used to analyze compounds that are generally smaller and less polar in comparison to those analyzed by HPLC-MS. A variety of compounds are analyzed by GC and GC-MS, which are useful for paleoenvironmental reconstructions. These include plant leaf waxes and a variety of lipids produced by marine and lacustrine algae.