Center for Stable Isotope Biogeochemistry

Solid materials

The Center for Stable Isotope Biogeochemistry (CSIB) at Berkeley accepts solid materials such as plant and animal tissues, soils, etc.,  for determination of stable isotope ratios of carbon, nitrogen, sulfur,  and oxygen at natural abundance.

Carbon and Nitrogen

  • δ13C and δ15N values of solid materials are determined by continuous flow (CF) dual isotope analysis using a CHNOS Elemental Analyzer interfaced to an IsoPrime100 mass spectrometer. Long-term external precision for C and N isotope determinations is  ± 0.10‰ and  ± 0.20‰, respectively.
  • Sample preparation: Solid samples should be ground to flour like consistency (a fine, 200 mesh, powder with no visibly different particles with naked eye) and weighed out in tin capsules on a six-place microbalance. The sample weight should be recorded if total % N or % C determinations are required. We recommend that you use either 4×6 mm (part #041070) or 3.5×5 mm tin capsules (part #041060) 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 carbon and nitrogen. Tin 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. Remember to remove carbonates from calcareous soils before analysis for SOM 13C.
  • Sample size: Samples for N measurement should contain 20-250 μg of N and samples for C measurement should contain 0.3-2 mg of C. Samples outside these size ranges can be analyzed but require a specialized analysis method. Contact us first to discuss the type of sample before preparing if outside the above ranges.  You may use the following formulas to determine sample size:

formula for carbon and nitrogen sample size

 Soil/sediment samples size should not exceed 80 mg/sample.

  • 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 15N13C 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).

If you are not clear about the best way to prepare your samples or are unsure about the optimal sample size(s) to use, please contact us before proceeding. Also if you have special requirements that do not fit within the guidelines provided here, contact us and we can help advise you on the best procedure to use.

GF/F filter material cannot be run on our instruments, please avoid/remove all particles of filter prior to sample encapsulation.

Carbon, Nitrogen and Sulphur

  • δ13C, δ15N and δ34S values of solid materials are determined by continuous flow (CF) triple isotope analysis using an EA IsoLink CNS IRMS System from Thermo Fisher Scientific. Long-term external precisions for C,  N and S isotope determinations are  ± 0.10‰,  ± 0.20‰, and ± 0.40‰, respectively.
  • Sample preparation: Solid samples should be ground to flour like consistency (a fine, 200 mesh, powder with no visibly different particles with naked eye) and weighed out in tin capsules on a six-place microbalance. The sample weight should be recorded if total % N, % C and %S determinations are required. We recommend that you use 3.5×5 mm (part #041060) 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 carbon and nitrogen. Tin capsules should be folded and compressed into a compact cylindrical or spherical shapes with a maximum dimension of 5 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. Remember to remove carbonates from calcareous soils before determination of C in SOM.
  • Sample size: Samples should contain 30-200 μg of N, 0.25-1 mg of C and 10-35 μg of S.  Please contact us before proceeding with soil/sediment samples preparation.
  • 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 15N13C34S 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).

If you are not clear about the best way to prepare your samples or are unsure about the optimal sample size(s) to use, please contact us before proceeding. Also if you have special requirements that do not fit within the guidelines provided here, contact us and we can help advise you on the best procedure to use.

GF/F filter material cannot be run on our instruments, please avoid/remove all particles of filter prior to sample encapsulation.

Carbon and Oxygen (carbonates)

  • δ 13C and  δ18O values of carbonates are determined using a MultiCarb system in line with a GV IsoPrime mass spectrometer in Dual Inlet. Several replicates of the international standard NBS19, and two lab standards (CaCO3 I & II) are analyzed along with the samples for each run. Long term external precisions for C and O are  ± 0.05‰ and  ± 0.07‰, respectively.
  • Sample size: analysis is performed on bulk powder samples containing about 10 to 100 μg calcite or aragonite.

Please contact us directly for shipping instructions.

Use our file “Sample name form for 13C18Ocarbonates” to fill in the names of each sample.

Oxygen

  • δ18O values 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-V-9 (cotton cellulose) is ± 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.

Sulfur

  • δ34S values of inorganic or organic solid materials with low S content (~5 μg sulfur per capsule) are determined by continuous flow (CF)SO2 using an Eurovector Elemental Analyser (EuroEA3028-HT) interfaced with a GV IsoPrime isotope ratio mass spectrometer. Long term external analytical precision is ± 0.2‰.
  • Sample preparation: Samples should be weighed out into 3.5×5 mm tin capsules (part #41060) 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 sulfur. Tin capsules should be folded and compressed into compact cylindrical or spherical shapes with a maximum dimension of 4 mm.
  • Sample size: Bulk powder samples or pure sulfate/sulfide samples  should contain between 5 and 35 μg sulfur.
  • 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 34S 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.

GF/F filter material cannot be run on our instruments, please avoid/remove all particles of filter prior to sample encapsulation.