Stable Isotope Protocols | Mass Spectrometry Facility | SIU

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Mass Spectrometry Facility

Stable Isotope Protocols

Sample preparation suggestions

The sample amount needed for IRMS analyses is a function of how much of the element of interest is present in the sample. Please contact the Dr. Mihai Lefticariu before weighing or submitting samples. Please note the Mass Spectrometry Facility does not run samples that are damaged, insufficiently prepared, or are considered to pose a hazard for the instruments if run.

  1. δ13C, δ15N, δ2H, δ18O and weight %C, N, H, and O in solid organic and inorganic samples with natural isotope abundances by CF-EA-IRMS and CF-TCEA-IRMS

    Please make sure the samples are ground/cut as fine as possible and thoroughly dried before weighing and packing them into tin (for EA) or silver (for TCEA) capsules. The capsules containing the sample should be gently crushed into round shapes without protruding ‘spikes’ or ‘winglets’ in order to optimize their drop into the combustion tube during runs. Samples requiring demineralization as part of preparation such as soil, sediment, and coal, for example, should be thoroughly washed with deionized water and dried before packing them into capsules to remove any traces of acid.

  2. δ13C, δ2H, weight %H and weight %C in oil samples with natural isotope abundances by CF-EA-IRMS and CF-TCEA-IRMS

    Use either a capsule designed for liquid samples or make sure that the regular capsule does not leak nor has oil on the outside.

  3. δ2H and δ18O in water samples with natural isotope abundances by CF-TCEA Liquid Injection-IRMS

    Natural water samples should be filtered to remove all suspended solids and the pH measured prior to sending them to the facility. A minimum sample volume of 5 ml is recommended.

  4. δ18O in water samples with natural isotope abundances by Gas Bench-Water equilibration-IRMSp

    A minimum sample volume of 10 ml is recommended.

  5. δ13C  and δ18O in carbonate samples with natural isotope abundances by off-line He flush/fill and acidification and Gas Bench-IRMS

The mineralogic composition of the sample should be known.