New guidelines for reporting stable hydrogen, carbon, and oxygen isotope-ratio data

Abstract

Oxygen and carbon stable isotopic studies constitute one of the primary tools used in paleoceanographic reconstruction, yet the calibration to PDB (Peedee belemnite) is surprisingly poorly known. The supply of PDB has been exhausted for more than two decades, and the PDB/•13C and /}180 scales are not uniquely defined [Gonfiantini, 1984]. This came about because laboratories used different materials for calibration as the supply of PDB was exhausted. Some laboratories were tied to one material and other laboratories to other materials. In 1984, Gonfiantini [1984] reported that the/}180 values (expressed relative to PDB) of the homogeneous, internationally distributed reference material NItS 19 calcite, as measured by 31 stable isotope laboratories from 19 countries, ranged from -2.42 to -1.53 %0; /•13C values ranged from + 1.75 to +2.33%0. Fortunately, today, the ranges among stable isotope laboratories are smaller, and those among paleoceanographic isotope laboratories may be still smaller. Nevertheless, there is room for improvement. 1994. Stichler, W., Interlaboratory comparison of new materials for carbon and oxygen isotope ratio measurements, Rep. IAEA-TECDOC-825, pp. 67-74, Int. At. Energy Agency, Vienna, 1995.

13C- and 15N-incorporation of doubly stable isotope labelled Lactobacillus johnsonii in humans

“…The precision (mean %RSD or CV) for 13 C and 15 N is 0.2% in the delta notation. An analytical grade urea standard (Serva Feinbiochemica GmbH, Heidelberg, Germany) calibrates both elemental composition and isotopic abundance for solid samples, whereas a 5 vol% CO 2 -standard gas is calibrated to allow delta values to be quoted against the Vienna-Pee-Dee Belemnite standard (Barrie et al, 1989;Coplen, 1996). The data were expressed either as enrichment d 13 C and d 15 N over baseline (DOB), as atom percent excess (APE), as parts per million excess (ppm excess) (Slater et al, 2001), as percentage of dose recovery in breath, or as percentage of cumulative urinary and faecal 13 C-and 15 N-excretion (PCE).…”

Foraging ecology of the endangered wood stork recorded in the stable isotope signature of feathers

“…Samples were combusted to N 2 and CO 2 in oxidation/reduction furnaces, separated by gas chromatography and then measured for 13 C/ 12 C and 15 N/ 14 N ratios on the mass spectrometer. An internal N 2(g) working standard was admitted prior to the introduction of each sample and a CO 2(g) standard was admitted at the conclusion of each combustion for calibration to the AIR (nitrogen) and V-PDB (carbon) international standards (Mariotti 1983;Coplen 1996). Stable isotope ratios 586 titioning of nitrogen isotopes in animals can be viewed as a steady state mass balance where excretory products (e.g., ammonia, uric acid, and urea) are depleted in 15 N, and tissues are enriched in 15 N compared with the diet.…”

Ambient water quality in aquifers used for drinking-water supplies, Gem County, southwestern Idaho, 2015

“…Hydrogen-isotope-ratio analyses were performed using the hydrogen equilibration technique (Coplen and others, 1991). Results for stable isotopes are in units of per mil (‰, parts per thousand), and expressed in delta notation (δ) as derived from comparing the sample to the Vienna Standard Mean Ocean Water (VSMOW) (Coplen, 1996). The two standard deviation (2-σ) accuracy of oxygen and hydrogen isotope results were 0.2 and 2‰, respectively Coplen, 2008a, 2008b).…”