Oxygen

  • δ18values of solid materials are determined in continuos flow (CF) using an Elementar PYRO Cube interfaced to a Thermo Delta V mass spectrometer. Long term external precision for IAEA V9 cotton cellulose is better than ± 0.20‰.
  • Sample preparation: Samples should be weighed out into 3.5×5 mm silver capsules (part #041066) from Costech Analytical Technologies, Inc. (http://www.costechanalytical.com/). Do not handle the boats with your bare hands (always use forceps) and make sure that the samples are free of any other material containing oxygen. Silver capsules should be folded and compressed into a compact cylindrical or spherical shapes with a maximum dimension of 6 mm. Entire objects of small mass such as insects, sections of root, leaf disks, can be packaged whole, but check with us first before packing these.
  • Sample size: Samples should contain ~ 150 μg oxygen per capsule (for example: 0.3 mg cellulose or bulk leaf, 0.6 mg of hair, 0.5 mg BaSO4, or 1 mg Ag3PO4)
  • Sample organization: Samples can be organized and shipped in 96-well culture plates (e.g., Costech “cell wells”,  part # 080016 ). Use our file “Sample name form for 18O solids to fill in the names and weights of each sample. Each plate should have a unique name and the sample code should include the plate name and the tray location or cell address (Rows A-H and columns 1-12 are marked on the plates).

Please contact us before preparing your samples so that we can discuss your application, sample sizes and sample preparation for the best current results.