Description

The laboratory/Stable isotopes biogeochemistry group has methodologies for the analysis of stable isotopes (18O/16O, 13C/12C, 15N/14N, 2H/1H and 34S/32S) in water, silicates, phosphates, carbonates, nitrates, sulfates, sulfides, organic matter and specific compounds, VOC (Volatile Organic Carbon), methane and NMHCs (non-methane hydrocarbons), DOC (Dissolved Organic Carbon), DIC (Dissolved Inorganic Carbon), atmospheric gases (CO2, O2, N2, Ar), etc.

The laboratory is equipped with 6 IRMS mass spectrometers (Delta V, Delta Plus XP, 3 Delta XL and Finnigan MAT 253) connected with various peripherals that allow the analysis of the isotopic ratios (13C/12C, 18O/16O, 15N/14N, 34S/32S and D/H) in different compounds; 4 laser systems (Picarro G1101-i, Picarro G2201-i, Picarro L2140-i and DLT-100 Los Gatos Research) are dedicated to the isotopic analysis of CO2 in air and isotopic analysis of water (vapour and liquid).

Delta Plus XP connected with:

• GasBench system
• Elemental Analyzer Carlo Elba NC1500 is dedicated to determine 13C/12C, 15N/14N, 34S/32S in inorganic and organic samples (animal and plant tissues), sulfates, nitrates, etc.

Delta V connected with:

• Gas chromatograph (Finnigan Trace CG ultra) with a “Y” outlet that allows a part of the sample may be derived to a quadrupole (Thermo Finnigan Trace DSQ) and the other part to a micro-oven that allows both combustion and pyrolysis (Finnigan CG Combustion III), which facilitate identification of each specific compound (alkanes, amino acids, etc.) and its subsequent isotopic analysis.
• SPME system (Solid Phase Microextraction): CombiPal +Trace GC ultra + Quadrupole DSQ + IRMS
• Atomx (Teledyne-Tekmar), an automatic “purge and trap” system with a “cold finger” for the extraction of VOC (Volatile Organic Carbon) connected to the mentioned gas chromatograph with “Y” output.

This configuration allows us to analyze stable isotopes (C, N, H, O) in carbonates, DIC in continental and marine waters, oxygen in water, dissolved oxygen in water (focused in the study of GPP-18 (Gross Primary Production), methane, NMHCs, VOC, specific compounds in organic matter (n-alkenes, amino acids, etc.), nitrates, N2O, etc.

3 Delta Plus XL connected with:

• Thermo Finnigan TC / EA high-temperature pyrolysis system to determine the 18O/16O and D/H ratios in liquids and solids (organic matter, sulphates, phosphates, nitrates, phyllosilicates, etc.).
• 1010 OI Analytical total organic carbon analyzer and Fisions Instruments NA1500 elemental analyzer for 13C/12C isotopic ratios in DOC.
• Elemental Analyzer Fisons dedicated to determine 34S/32S 

Finnigan MAT 253

A double-entry system that allows a high-resolution isotope analysis in CO2 and O2. “Clumped Isotopes” of CO2 allow the calculation of paleotemperatures without having to assume the water with which carbonate was in equilibrium. The “clumped-isotopes” of O2 are helpful for studying the balance between photosynthesis and respiration in different marine and continental ecosystems.

Responsible technician: Arsenio Granados Torres
Scientific advisor: Antonio Delgado Huertas