Address: 237 Deike Building
Description: This gas chromatograph is used routinely to measure hydrocarbons, e.g methane (CH4) and ethane (C2H6) in gas or water samples from streams or wells. This techique reproducibly measures methane concentrations as low as 0.06 µg CH4/Liter of water sample. This detection limit is lower, if not the lowest detection limit, reported by academic or commercial laboratories.
Staff Expertise: We have developed a novel technique to measure both the concentration and isotopic (13C/12C) ratio of methane dissolved in water (Wendt et al. 2018). The technique reproducibly measures [CH4] in stream water down to 0.06 µg CH4/L, lower than most commercial laboratories where detection limits have been reported as 1, 5, or 26 µg CH4/L (Li et al. 2016). A custom-designed vacuum inlet system for the GC allows for reporting a low detection limit for samples that have low concentrations and limited volume (Sowers et al. 1997; Sowers and Jubenville 2000). Our detection limit is lower than the equilbrium CH4 concentration in water (0.08 µg CH4/L) in contact with present day CH4 concentrations in air, 1.87 + 0.01 ppm. In addition to CH4, we can also measure headspace gaseous composition for CO2, C2H6, C3H8, C4H10. All measurements are performed using standard industry wide techniques with comparable precision and accuracy.