title: Accuracy and precision of a laser-spectroscopy approach to the analysis of δ²H and δ¹⁸O in human urine.
abstract: The isotope ratio analysis of body water often involves large sample numbers and lengthy sample processing. Here we demonstrate the ability of isotope ratio infrared spectroscopy (IRIS) to rapidly and accurately analyse the isotope ratios of water in urine. We analysed water extracted from human urine using traditional isotope ratio mass spectrometry (IRMS) and compared those values with IRIS-analysed extracted water and un-extracted urine. Regression analyses for δ²H and δ¹⁸O values between (1) extracted water analysed via IRMS and IRIS and (2) urine and extracted water analysed via IRIS were significant (R²=0.99). These results indicate that cryogenic distillation of urine was not required for an accurate estimate of the isotopic composition of urine when using IRIS.
authors.affiliation: Department of Biology, University of Utah, Salt Lake City, UT 84112, USA. ogrady@biology.utah.edu
authors.forename: Shannon P
authors.initials: SP
authors.lastname: O'Grady
authors.forename: Lindsey E
authors.initials: LE
authors.lastname: Enright
authors.forename: Janet E
authors.initials: JE
authors.lastname: Barnette
authors.forename: Thure E
authors.initials: TE
authors.lastname: Cerling
authors.forename: James R
authors.initials: JR
authors.lastname: Ehleringer
mesh_terms: D003903:Deuterium / Q000032:analysis*; D006801:Humans; D007834:Lasers; D010103:Oxygen Isotopes / Q000032:analysis*; D015203:Reproducibility of Results; D013057:Spectrum Analysis / Q000379:methods*
chemical_list: D010103:Oxygen Isotopes; D003903:Deuterium