An automated method for the determination of the TEX₈₆ and U₃₇^K' paleotemperature indices

The relative abundances of archaeal glycerol dialkyl glycerol tetraether (GDGT) compounds (TEX₈₆) and alkenone lipids (U₃₇^K') are commonly used paleoceanographic proxies for temperature. These proxies are analyzed by high-performance liquid chromatography (HPLC) and gas chromatography (GC) methods, respectively, and traditionally, the peaks corresponding to the individual compounds are integrated by hand. Here, we introduce a MATLAB software package called ORIGAmI (ORganIc Geochemistry peAk Integration) that allows for automated, reproducible determination of these indices and quantification of lipid concentrations. The method is based on modeling the peaks with individual Gaussian curves. Comparisons with manually integrated data demonstrate that the method is accurate and precise. Furthermore, automating the peak detection and quantification process reduces both analysis time and user error.