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The consortium has access to a unique constellation of analytical facilities for CSIA, ranging from extraction and purification methods (e.g. Soxhlet, Accelerated Solvent Extraction - ASE, and preparative capillary gas chromatography - pcGC) and quantification of target-compound concentrations (e.g. GCMS), to isotope analysis of radiocarbon, stable carbon, bromine, chlorine, nitrogen and hydrogen.
The isotope analysis of samples delivered from WP2 and WP3 is divided into methods with on-line analysis and off-line methods.
On-line methods: δ15N, δ13C, δ2H and δ81Br
The purified extracts are directly injected and separated in GC that is hyphenated to a combustion interface and subsequent isotope-ratio mass spectrometry (IRMS). The MS is usually a magnetic-sector instrument with simultaneous detection of the two isotopic ion beams resulting from electron ionization (EI) of the combustion products (e.g. CO2 for carbon). Bromine isotopes are analyzed with a GC-ICP-MS system equipped with a multicollector detector.
Off-line methods: Δ14C, δ37Cl
The target compounds are isolated and harvested from the extracts by repetitive injections on pcGC, resulting in >95% pure compounds for isotope analysis. The samples for Δ14C and δ 37Cl/δ81Br are then combusted with CuO in vacuum-sealed quartz tubes to liberate the carbon isotopes as CO2 for determination of Δ14C with AMS, and the halogen
New methods for CSIA will be explored as part of the isoSoil laboratories continuous quest to improve detection limits, accuracy and time efficiency. For instance, bromine (and possibly chlorine) isotopes will be analyzed by gaschromatography hyphenated to inductively-coupled plasma multi-collector mass spectrometry (GC-ICP-mcMS). Further, tests will be performed to use common bench-top GC-MS units for preliminary isotope analyses of e.g. chlorine in chlorinated solvents. This type of “low-precision” method can be useful in special cases where the attenuation of target compounds give strong isotopic shifts (powerful ε or small f). Such “rough” techniques will enable analysis at conventional laboratories and further spread the use and interest of CSIA.

The research has received funding from the European Community's Seventh.
Framework Programme FP7/(2009-2012) under grant agreement no 212781.