Compound Specific Isotope Analysis (CSIA) by GC-C-IRMS
The SIF provides routine compound-specific 13C isotope analysis of a variety of compounds using GC-combustion isotope ratio mass spectrometry (GC-C-IRMS). Compound-specific 15N isotope analysis for some compounds is also available (e.g., amino acid derivatives). 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 Pierce Reagents, Solvents and Accessories Handbook. Once separated chromatographically, each compound is entirely combusted to gases (CO2, N2) and subsequently introduced into the isotope ratio mass spectrometer. Analysis is performed using a Thermo GC-C-IRMS system composed of a Trace GC Ultra gas chromatograph (Thermo Electron Corp., Milan, Italy) coupled to a Delta V Advantage isotope ratio mass spectrometer through either a GC/C-III (C,H analysis) or GC IsoLink (N analysis) interface (Thermo Electron Corp., Bremen, Germany). Compound identification support for the CSIA laboratory has been provided by a Varian CP3800 gas chromatograph coupled to a Saturn 2200 ion trap MS/MS (Varian, Inc., Walnut Creek, CA U.S.A.).
e-mail: firstname.lastname@example.org | phone: 530-752-8100 | fax: 530-752-4361
UC Davis Stable Isotope Facility | Department of Plant Sciences
One Shields Avenue | Davis, California, 95616 | USA