Isotope Biochemistry Laboratory

Facilities

A wide range of applications in macronutrient metabolism is served by a comprehensive array of externally funded analytical equipment. This includes: 12 mass spectrometers for structural and isotopic analysis; indirect calorimeter; GC/FID; HPLC; UV/Vis spectrophotometry; infra-red gas analysers; heart rate monitors; physical activity meters.

 

Analytical Platforms

Organic Mass Spectrometry

GCMS:
HP 5890II/VG Trio-1000 EI single quadrupole
Thermo Polaris Q EI/CI ion trap MSn

LCMS:
Dionex LC/ VG Platform ESI single quadrupole

Compound-specific Isotope Analysis

GC-C-IRMS:
Ai93/ Europa 20-20 IRMS
Agilent 6890/ GV Optima IRMS

LC-IRMS:
Dionex ICS3000/ GV Isoprime IRMS

Gas Analysis

AP2003 IRMS (breath 13C; 18O in fluids)
Europa HYDRA (2H & 18O in fluids; breath 13C)

Bulk Analysis

Carlo Erba NA1500/ Finnigan MAT IRMS (13C, 15N, 18O)
Europa ANCA/20-20 IRMS (13C, 15N, 18O, 2H, 34S)
Europa Roboprep / 20-20 IRMS (13C, 15N)
Europa Roboprep/ TracerMass (13C, 15N)


Sample Preparation and Processing

We have experience of processing a wide range of biological samples (urine; breath; blood; tissue; saliva; gastric juice; faeces) and environmental samples (water; biomass; sediments).  Facilities include: protein hydrolysis; saponification; SPE; ultrafiltration; ion exchange; centrifugation; freeze drying; vacuum concentration; derivatisation.

 

Compound specific isotope analysis

Bulk isotope measurements have been the mainstay of ecological and environmental stable isotope measurements but recent advances in instrumentation now allow isotope measurements of specific compounds. CSIA is required for biological applications of stable isotopes and SIBL utilies both GC-C-IRMS and LC-IRMS.

 

GC-C-IRMS

Analytes are first separated by gas chromatography and each analyte eluting from the GC column is quantitatively converted to CO2 (for 13C/12C analysis) and N2 (for 15N/14N analysis) before analysis by IRMS. Two systems are operational at SUERC; GV Instruments Isochrome III and an in-house designed system. Currently the Isochrome is dedicated to fatty acid methyl ester analysis and the Orchid system for short chain fatty acids (SCFA).

 

LC-IRMS

SUERC has recently invested in liquid chromatography (LC) IRMS capability in support of a wide range of environmental and biological research areas. The utility of LC-IRMS comes from the ability to measure natural abundance isotope ratios in, often underivatised samples, which are polar and often not amenable to GC methods. We are developing anion chromatography methods, exploiting Dionex aqueous separations technology, for rapid, high resolution separations for IRMS analysis using GV Instruments Liquiface interface technology. This LC-IRMS combination has many applications in compound specific isotope analysis at natural abundance and in tracer studies towards functional metabolomics.