EcoCore Analytical Services

The Stable Isotope Laboratory at EcoCore (EcoCore-IsoLab) is a service, research and teaching facility for the study of isotopes in ecology and environmental sciences. Analyses are performed by researchers themselves or by EcoCore, and charged per sample. The facility provides students and researchers valuable hands-on experience with the instruments, and assists CSU faculty in facilitating labs for isotope-related classes and workshops. Click here for some of the educational support provided by the lab.

CSU-IsoLab possesses three isotope ratio mass spectrometers (IRMS), several interfaces and preparation systems that enable isotope analyses of different elements (C, N, O, H) in solid, liquid and gas at atmospheric and trace concentrations. The facility management maintains the instruments, develops methods and provides training. Within the lab, an area is designed for teaching, research seminars and small workshops, which can be used by CSU faculty.

Analytical capabilities and equipment:

• Solid sample ¹³C and ¹⁵N analysis
• ¹³C analysis of CO₂ in concentrated samples
• ¹⁸O analysis of water
• Trace gas isotope analysis
• Compound-specific stable isotope analyses

Solid sample ¹³C and ¹⁵N analysis by Carlo Erba NA 1500 (Milano, IT) elemental analyzer coupled to a VG Isochrom continuous flow IRMS (Isoprime Inc., Manchester, UK).  An integrated thermal conductivity detector (TCD) also allows the determination of carbon and nitrogen concentrations simultaneously with an isotopic determination. Each analysis (¹³C or ¹⁵N) requires one sample.

¹³C analysis of CO₂ in concentrated samples  (e.g. from incubations) by micro-gas Injector coupled to a VG Optima IRMS (Isoprime Inc., Manchester, UK). Requires manual injection.

¹⁸O analysis of water by CO₂ equilibration (equilibration block) and micro-gas Injector with auto-sampler coupled to a VG Optima IRMS (Isoprime Inc., Manchester, UK). The lab also has a vacuum line for extracting water from soils and plant tissues.

Trace gas isotope analysis (i.e. CO₂, N₂O and CH₄) by Thermo PreCon coupled to a Delta V IRMS (Thermo Scientific). The PreCon is a fully automated trace gas pre-concentrator for the isotope characterization of N₂O, CH₄ and CO₂ at natural concentrations. Following manual gas injection, the PreCon carries out sample concentration, purification, cryofocusing, and injection onto a gas chromatograph prior to IRMS analysis. Currently configured for ¹³C analysis of CO₂ at atmospheric concentrations.

Compound-specific stable isotope analyses by a Thermo GC-c/py-IRMS system composed of a Trace GC Ultra gas chromatograph with TriPlus autosampler, GC IsoLink Unit, coupled to a Delta V Advantage IRMS through a ConFlo IV universal interface (Thermo Scientific). FAME identification support is provided by GC-MS (Thermo Scientific Trace DSQ) at the PMF Core Facility at CSU. The instrument allows for the determination of ¹⁸O and ²H on CO and H₂ generated by pyrolysis (1450°C), and ¹³C and ¹⁵N on CO₂ and N₂ generated by combustion (1030°C). The instrument is currently configured for ¹³C analysis in fatty acid methyl esters (FAMEs). FAMEs dissolved in hexane are injected in splitless mode and separated on a DB-5 column (30m x 0.25mm ID x 0.25um film thickness). δ¹³C values are corrected using C12:0 and C19:0 working standards calibrated against NIST standard reference materials.