The Bristol node of the NERC Life Sciences Mass Spectrometry Facility (LSMSF), is located in the School of Chemistry at the University of Bristol and comprises eight state-of-the-art mass spectrometers and associated instrumentation that are housed within the laboratories of the Organic Geochemistry Unit (OGU). The OGU is a subdivision of the Bristol Biogeochemistry Research Centre and has a record of more than 30 years of international research activity employing mass spectrometry as its principal analytical tool. The Facility provides a specialist service to members of the UK life sciences community providing the separation and mass spectrometric characterisation of complex mixtures of organic compounds found in biological and environmental materials. The strength of the Facility lies in its use of 'hyphenated techniques', i.e. GC/MS and HPLC/MS to resolve these mixtures ('fingerprint' distributions) and identify discrete molecular components (inferred from mass spectra). In addition and where appropriate, compound specific light stable isotope (C, H, N or O) mass spectrometry is also available thereby potentially providing a further stable isotopic dimension to the analysis of samples.