title: USGS48 Puerto Rico precipitation - a new isotopic reference material for δ2H and δ18O measurements of water.
abstract: A new secondary isotopic reference material has been prepared from Puerto Rico precipitation, which was filtered, homogenised, loaded into glass ampoules, sealed with a torch, autoclaved to eliminate biological activity, and calibrated by dual-inlet isotope-ratio mass spectrometry. This isotopic reference material, designated as USGS48, is intended to be one of two isotopic reference waters for daily normalisation of stable hydrogen (δ(2)H) and stable oxygen (δ(18)O) isotopic analysis of water with a mass spectrometer or a laser absorption spectrometer. The δ(2)H and δ(18)O values of this reference water are-2.0±0.4 and-2.224±0.012 ‰, respectively, relative to Vienna Standard Mean Ocean Water on scales normalised such that the δ(2)H and δ(18)O values of Standard Light Antarctic Precipitation reference water are-428 and-55.5 ‰, respectively. Each uncertainty is an estimated expanded uncertainty (U=2u(c)) about the reference value that provides an interval that has about a 95 % probability of encompassing the true value. This isotopic reference water is available by the case of 144 glass ampoules containing 5 mL of water in each ampoule.
authors.affiliation: a U.S. Geological Survey , Reston , VA , USA.
authors.forename: Haiping
authors.initials: H
authors.lastname: Qi
authors.forename: Tyler B
authors.initials: TB
authors.lastname: Coplen
authors.forename: Lauren
authors.initials: L
authors.lastname: Tarbox
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Lorenz
authors.forename: Martha
authors.initials: M
authors.lastname: Scholl
mesh_terms: D002138:Calibration; D003903:Deuterium / Q000032:analysis*; D004784:Environmental Monitoring; D013058:Mass Spectrometry; D010100:Oxygen / Q000032:analysis*; D010103:Oxygen Isotopes / Q000032:analysis; D011647:Puerto Rico; D011834:Radiation Monitoring / Q000379:methods*; D011891:Rain / Q000737:chemistry*; D012016:Reference Values; D013057:Spectrum Analysis; D014867:Water / Q000032:analysis*
chemical_list: D010103:Oxygen Isotopes; D014867:Water; D003903:Deuterium; D010100:Oxygen
keywords: USGS48; hydrogen-2; isotope hydrology; isotope measurements; methods and equipment; oxygen-18; quality assurance; quality control; reference material