Freshwater Institute (DFO Winnipeg) Stable Isotope Laboratory quality assurance/quality control and inter-lab comparison report /

The use of stable isotopes as a food web biotracers has become accepted and commonly used globally in marine, freshwater and terrestrial ecosystems. This report was written to provide researchers interested in working with Fisheries and Oceans-Freshwater Institute’s (FWI) stable isotope laboratory with quality control and quality assurance information. FWI’s stable isotope analysis system was evaluated relative to three well established stable isotope analysis laboratories (University of Waterloo’s Environmental Isotope Laboratory, University of Windsor’s Chemical Tracers Lab and University of Ottawa’s G.G Hatch Stable Isotope Laboratory). The internal precision and inter-laboratory reproducibility of d13C and d15N analysis was determined for a variety of fish, whale and invertebrate samples. Long term internal repeatability of an in-house fish standard is +/-0.08 ‰ for d13C and +/-0.1 ‰ for d15N. Overall, agreement between FWI and reference laboratories was acceptable (average d13C +/-0.08 ‰, average d15N +/-0.16) demonstrating that d13C and d15N data produced by FWI can be readily compared with data produced by established SIA laboratories.