Stable Isotope Analysis
EcoCore has two isotope ratio mass spectrometers (IRMS) and several peripherals that allow for Carbon, Nitrogen and Oxygen isotope measurements in a variety of solid, liquid and gas samples. EcoCore also has a cavity ring down spectrometer for the measurement of ẟ2H (or ẟD) and ẟ18O in water. EcoCore management maintains the instruments, develops methods and calibrations, and provides training and other technical support. Clients may receive training and analyze their own samples or submit samples to be analyzed by EcoCore staff.
Analytical Capabilities:
Solid sample ẟ13C and ẟ15N analysis
ẟ13CO2 analysis of gas samples
ẟ13C and ẟ18O analysis of carbonates
Water ẟ2H and ẟ18O analysis
Solid sample ẟ13C and ẟ15 N analysis
Solid sample analysis is performed using a Costech ECS 4010 elemental analyzer (Costech International, Milano, Italy) coupled to a Thermo-Fisher Delta V Advantage isotope ratio mass spectrometer (Thermo-Fisher, Bremen, Germany). Both ẟ13C and ẟ15N can be measured on the same sample. Multiple methods with different carbon dilution factors allow analysis of samples with a wide range of C to N ratios. A 49-position sequential autosampler and automatic shutdown allow for up to 8 hours of unattended operation. A microgram balance is available to allow measurement of C and N concentrations along with the isotopic ratios. The instrument can be used to measure C and N concentrations at much lower levels than the minimums listed for isotopic measurements.
Enriched samples may be analyzed with prior approval by management.
Clients may receive training and analyze their own samples. Samples may be submitted pre-weighed into tin capsules for analysis by EcoCore staff, see the “samples size calculator” to determine the correct sample amount. Bulk samples may also be submitted. Contact EcoCore management for details prior to sending samples.
Soil and sediment samples should be tested for inorganic carbon (carbonates) before analysis. Carbonates can be removed by acid fumigation although this usually has a negative impact on 15N measurements. Contact EcoCore management for guidance.
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ẟ13C |
ẟ15N |
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Observed precision |
0.2‰ |
0.3‰ |
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Minimum sample size* |
1 µmol C |
4 µmol N |
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Run time/sample |
9 min |
9 min |
ẟ13C analysis of CO2 gas samples
ẟ13C analysis of CO2 gas samples is performed using a Thermo Precon device coupled to a Thermo-Fisher Delta V Advantage isotope ratio mass spectrometer (Thermo-Fisher, Bremen, Germany). The Precon unit was designed to measure N2O and CH4 but has been modified to measure CO2. Following manual gas injection, the PreCon carries out sample concentration, purification, cryofocusing, and injection into a gas chromatograph prior to IRMS analysis.
The instrument is routinely used to measure samples ranging from 400 to 2500 ppm CO2 but this range can be extended by changing the injection size. CO2 concentrations are determined using an Infrared Gas Analyzer (IRGA) prior to isotopic analysis.
Clients may receive training and analyze their own samples or may submit samples for analysis by EcoCore staff. Contact management for more information.
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ẟ13C analysis of CO2 |
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Observed precision* |
0.2‰ |
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Sample size range |
0.007 - 0.021 µmol CO2 |
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Run time/sample |
11 min |
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*Standard deviation of 34 injections over 3 running days |
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ẟ13C and ẟ18O analysis of carbonates
Solid carbonate samples are dissolved using acid prior analysis as per directions. The measurement of the extracted carbonate CO2 is performed utilizing a Thermo-Fisher Gasbench II analyzer with attached autosampler (PAL System) coupled to a ConFlo IV universal interface and a Delta V Advantage isotope ratio mass spectrometer (both Thermo-Fisher, Bremen, Germany). It possible to collect quantitative sample data for both ẟ13C and ẟ18O. A sequential autosampler (up to 96 sample spots) and automatic shutdown allows for multiple hours of unattended operation.
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ẟ13C |
ẟ18O |
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Observed precision |
0.15‰ |
0.2‰ |
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Minimum sample size* |
150 µg calcium carbonate |
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Water ẟ2H (ẟD) and ẟ18O analysis
For measurement of stable isotopes of ẟ18O and ẟ2H (ẟD) in water samples a Picarro L2130-i is used to collect fast, precise and accurate data. After stabilization of the instruments cavity (T, humidity) samples are introduced via an attached autosampler and vaporized into gas which is instantly measured by an infrared laser cavity ringdown system.
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ẟ2H (ẟD) |
ẟ18O |
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Observed precision |
1.0‰ |
0.2‰ |
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Minimum sample size* |
1ml (inquire if you have smaller samples) |
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