Because stable isotope analysis techniques typically use sample weights in the order of 1 to 5 milligrams, considerable attention should be given to sample preparation. To achieve reliable data samples must be of acceptable homogeneity and be representative of the whole. Samples should be dehydrated by freeze drying or oven drying at 40’C to 70’C (depending on material type) then finely ground using a mortar & pestle or a ball mill. Inorganic carbon in the form of carbonates can interfere with the measurements of organic 13C in soils or sediments. If inorganic carbon is present it can be eliminated by careful direct acidification with dilute hydrochloric acid or indirectly by exposure to concentrated sulphurous acid vapour. We are able to prepare or pre-treat your samples at additional cost. Please contact us to discuss any aspects of sample preparation that you may require.
Most of our customers submit dried and prepared samples for analysis in vials or bottles ready for us to weigh and run on our systems. In this case we will determine the workable weight ranges best suited for a particular analysis. Generally, if the %C:%N is less than 40, it is possible for us to determine 15N/14N and 13C/12C simultaneously on a single weighed sample. Please contact us to discuss your requirements.
Samples submitted for analysis should be catalogued (emailed Excel spread sheets are preferred when many samples are submitted).
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