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Jennifer M. Lorenz

Publications and source records attributed to Jennifer M. Lorenz.

7 recordsLinked to original sources
USGS2016

Antarctic ice-core water (USGS49) – A new isotopic reference material for δ2H and δ18O measurements of water

As a result of the scarcity of isotopic reference waters for daily use, a new secondary isotopic reference material for international distribution has been prepared from ice-core water from the Amundsen–Scott South Pole Station. This isotopic reference material, designated as USGS49, was filtered, homogenised, loaded into glass ampoules, sealed with a torch, autoclaved to eliminate biological activity and measured by dual-inlet isotope-ratio mass spectrometry. The δ 2 H and δ 18 O values of USGS49 are −394.7 ± 0.4 and −50.55 ± 0.04 mUr (where mUr = 0.001 = ‰), respectively, relative to VSMOW, on scales normalised such that the δ 2 H and δ 18 O values of SLAP reference water are, respectively, −428 and −55.5 mUr. Each uncertainty is an estimated expanded uncertainty ( U = 2 u c ) about the reference value that provides an interval that has about a 95% probability of encompassing the true value. This isotopic reference material is intended as one of two isotopic reference waters for daily normalisation of stable hydrogen and oxygen isotopic analysis of water with an isotope-ratio mass spectrometer or a laser absorption spectrometer. It is available by the case of 144 glass ampoules or as a set of sixteen glass ampoules containing 5 ml of water in each ampoule.

Geostandards and Geoanalytical Research↗
USGS2015

A new isotopic reference material for stable hydrogen and oxygen isotope-ratio measurements of water—USGS50 Lake Kyoga Water

Rationale As a result of the need for isotopic reference waters having high δ 2 H VSMOW-SLAP and δ 18 O VSMOW-SLAP values for daily use, especially for tropical and equatorial-zone freshwaters, a new secondary isotopic reference material for international distribution was prepared from water collected from Lake Kyoga, Uganda. Methods This isotopic reference lakewater was filtered through a membrane with 0.2-µm pore size, homogenized, loaded into glass ampoules that were sealed with a torch and autoclaved to eliminate biological activity, and measured by dual-inlet isotope-ratio mass spectrometry. This reference material is available in a case of 144 glass ampoules each containing 5 mL of water. Results The δ 2 H and δ 18 O values of this reference material are +32.8 ± 0.4 and +4.95 ± 0.02 mUr (milliurey = 0.001 = 1 ‰), respectively, relative to VSMOW, on scales normalized such that the δ 2 H and δ 18 O values of SLAP reference water are, respectively, −428 and −55.5 mUr. Each uncertainty is an estimated expanded uncertainty ( U  = 2 u c ) about the reference value that provides an interval that has about a 95 % probability of encompassing the true value. Conclusions This isotopic reference material, designated as USGS50, is intended as one of two reference waters for daily normalization of stable hydrogen and oxygen isotopic analysis of water with an isotope-ratio mass spectrometer or a laser absorption spectrometer, of use especially for isotope-hydrology laboratories analyzing freshwater samples from equatorial and tropical regions.

Lake Kyoga↗
USGS2014

Biscayne aquifer drinking water (USGS45): a new isotopic reference material for δ 2 H and δ 18 O measurements of water

RATIONALE As a result of the scarcity of isotopic reference waters for daily use, a new secondary isotopic reference material for international distribution has been prepared from drinking water collected from the Biscayne aquifer in Ft. Lauderdale, Florida. METHODS This isotopic reference water was filtered, homogenized, loaded into glass ampoules, sealed with a torch, autoclaved to eliminate biological activity, and measured by dual-inlet isotope-ratio mass spectrometry. This reference material is available by the case of 144 glass ampoules containing either 4 mL or 5 mL of water in each ampoule. RESULTS The δ 2 H and δ 18 O values of this reference material are –10.3 ± 0.4 ‰ and –2.238 ± 0.011 ‰, respectively, relative to VSMOW, on scales normalized such that the δ 2 H and δ 18 O values of SLAP reference water are, respectively, –428 and –55.5 ‰. Each uncertainty is an estimated expanded uncertainty ( U  = 2 u c ) about the reference value that provides an interval that has about a 95 % probability of encompassing the true value. CONCLUSIONS This isotopic reference material, designated as USGS45, is intended as one of two isotopic reference waters for daily normalization of stable hydrogen and oxygen isotopic analysis of water with an isotope-ratio mass spectrometer or a laser absorption spectrometer.

Rapid Communications in Mass Spectrometry↗
USGS2014

USGS48 Puerto Rico precipitation - A new isotopic reference material for δ 2 H and δ 18 O measurements of water

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 =2 u 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.

Puerto Rico↗
USGS2013

Lake Louise Water (USGS47): A new isotopic reference water for stable hydrogen and oxygen isotope measurements

"RATIONALE: Because of the paucity of isotopic reference waters for daily use, a new secondary isotopic reference material has been prepared from Lake Louise water from Alberta, Canada for international distribution. MOTHODS: This water was filtered, homogenized, loaded into glass ampoules, sealed with a torch, autoclaved to eliminate biological activity, and measured by dual-inlet isotope-ratio mass spectrometry. This isotopic reference water is available by the case of 144 glass ampoules containing 5 mL of water in each ampoule. RESULTS: The δ2H and δ18O values of this reference water are –150.2 ± 0.5 ‰ and –19.80 ± 0.02 ‰, respectively, relative to VSMOW on scales normalized such that the δ2H and δ18O values of SLAP reference water are, respectively, –428 and –55.5 ‰. Each uncertainty is an estimated expanded uncertainty (U = 2uc) about the reference value that provides an interval that has about a 95-percent probability of encompassing the true value. CONCLUSION: This isotopic reference material, designated as USGS47, is intended as one of two isotopic reference waters for daily normalization of stable hydrogen and stable oxygen isotopic analysis of water with a mass spectrometer or a laser absorption spectrometer. "

Rapid Communications in Mass Spectrometry↗
USGS2013

USGS46 Greenland ice core water – A new isotopic reference material for δ2H and δ18O measurements of water

Ice core from Greenland was melted, filtered, homogenised, loaded into glass ampoules, sealed, autoclaved to eliminate biological activity, and calibrated by dual-inlet isotope-ratio mass spectrometry. This isotopic reference material (RM), USGS46, is intended as one of two secondary 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 measured δ 2 H and δ 18 O values of this reference water were −235.8 ± 0.7‰ and −29.80 ± 0.03‰, respectively, relative to VSMOW on scales normalised such that the δ 2 H and δ 18 O values of SLAP reference water are, respectively, −428 and −55.5‰. Each uncertainty is an estimated expanded uncertainty ( U = 2 u c ) about the reference value that provides an interval that has about a 95-percent probability of encompassing the true value. This reference water is available in cases containing 144 glass ampoules that are filled with either 4 ml or 5 ml of water per ampoule.

Geostandards and Geoanalytical Research↗
USGS2013

The δ2H and δ18O of tap water from 349 sites in the United States and selected territories

Because the stable isotopic compositions of hydrogen (δ 2 H) and oxygen (δ 18 O) of animal (including human) tissues, such as hair, nail, and urine, reflect the δ 2 H and δ 18 O of water and food ingested by an animal or a human and because the δ 2 H and δ 18 O of environmental waters vary geographically, δ 2 H and δ 18 O values of tap water samples collected in 2007-2008 from 349 sites in the United States and three selected U.S. territories have been measured in support of forensic science applications, creating one of the largest databases of tap water δ 2 H and δ 18 O values to date. The results of replicate isotopic measurements for these tap water samples confirm that the expanded uncertainties (U = 2μ c ) obtained over a period of years by the Reston Stable Isotope Laboratory from δ 2 H and δ 18 O dual-inlet mass spectrometric measurements are conservative, at ±2‰ and ±0.2 ‰, respectively. These uncertainties are important because U.S. Geological Survey data may be needed for forensic science applications, including providing evidence in court cases. Half way through the investigation, an isotope-laser spectrometer was acquired, enabling comparison of dual-inlet isotope-ratio mass spectrometric results with isotope-laser spectrometric results. The uncertainty of the laser-based δ 2 H measurement results for these tap water samples is comparable to the uncertainty of the mass spectrometric method, with the laser-based method having a slightly lower uncertainty. However, the δ 18 O uncertainty of the laser-based method is more than a factor of ten higher than that of the dual-inlet isotoperatio mass spectrometric method.

Guam, Puerto Rico, St. John, U.S. Virgin Islands↗