Compound Specific Isotope Analysis (CSIA) by GC-C-IRMS

The SIF provides routine compound-specific ²H, ¹³C, ¹⁵N, and ³⁷Cl isotope analysis of a variety of compounds using GC-combustion isotope ratio mass spectrometry (GC-C-IRMS). Compounds must generally be isolated from bulk sample materials, such as soils, sediments, or biological tissues, using multi-step preparative procedures prior to chromatographic analysis. Non-volatile organic compounds must be derivatized by silylation, alkylation, acylation, esterification or other methods in order to make them volatile and improve chromatographic separation. Examples can be found in the Thermo Scientific Reagents, Solvents and Accessories Handbook. Once separated chromatographically, each compound is entirely combusted to gases (H₂, CO₂, N₂) and subsequently introduced into the isotope-ratio mass spectrometer. Analysis is performed using Thermo GC-C-IRMS systems composed of a Trace GC Ultra or 1310 gas chromatographs (Thermo Electron Corp., Milan, Italy) coupled to either a Delta Plus Advantage, Delta V Advantage, or MAT 253 isotope-ratio mass spectrometer through either a GC IsoLink or GC IsoLink II interface (Thermo Electron Corp., Bremen, Germany). Compound identification support for the CSIA laboratory is been provided by a Thermo ISQ single-quadrupole MS (Thermo Electron Corp., Bremen, Germany).

Important Information Regarding Compound-Specific Stable Isotope Analysis