SIL – STABLE ISOTOPE LAB

• Analysis
  13C of DIC and DOC
  

• Sample Preparation
  https://drive.google.com/file/d/1wydRGOdz8sQevTVw4LgR5NhY5tuED9Kk/view

1. Label the vials
2. Add 100ul of concentrated phosphoric acid in the vials.
3. Close the vials with a white cap/septum (the acid should not come in contact with the septum).
4. Flush the vials with Helium (100ml/min) for 5 minutes. The prepared vials could be used several weeks.
5. Inject max 5ml sample of water through the septum.

(Note! Samples should be injected into the vial during the sampling in the field (outgassing of CO2!).
The samples should be stored cool between sampling and analysis. Before analysis put the samples at room temperature overnight.

Please provide samples and a file with sample number and name.

• Quality control
  Carm-2 and CaCO3-merck.
• Recent Publications
  Brüchert, V., L. Bröder, J. E. Sawicka, T. Tesi, S. P. Joye, X. Sun, I. P. Semiletov, and V. A. Samarkin (2018), Carbon mineralization in Laptev and East Siberian sea shelf and slope sediment, Biogeosciences, 15(2), 471.
  
  Rocher-Ros, G., Harms, T.K., Sponseller, R.A., Väisänen, M., Mörth, C.-M. and Giesler, R. (2021), Metabolism overrides photo-oxidation in CO2 dynamics of Arctic permafrost streams. Limnol Oceanogr, 66: S169-S181. https://doi.org/10.1002/lno.11564

• Analysis
  13C and 2H for CH4
  13C of CO2
  
• Low concentration samples require to use Precon.
• Prior to isotope analysis, the concentration should be known to achieve good results for isotopes.
• E-mail Kasun (kasun.gayantha@geo.su.se) for training arrangement.

• Analysis
  13C and 18O of Carbonates (e.g., Foraminifera, Stalagmites etc.)
  
• Sample Preparation
  Note: Before use clean utensils using ethanol and Kim wipes, allow to dry! Samples should be dried/freeze-dried and homogenized.

• Label glass vials (Labco 738W – white cap).
• Weigh 0.2mg sample material/standard in the vials (applies to 100% carbonate samples).
  Use a silver capsule and check after each sample the weight!
  Close the vials with caps/septa.
• Dry overnight with removable lid at 90 degrees and if foraminifera dry at 50 degrees.
• Take out and add in a horizontal position 100µl H3PO4 (≥ 99%) on the wall (acid shouldn't touch the sample).
• Close the lid and put the vial in the flush rack still horizontal. Flush the vials with Helium (100ml/min) for 10 minutes.
• Place all tubes in the vertical position and allow acid to react at room temperature with the samples overnight.
  
  If the samples are not calcite the temperature and time for the reaction may differ.
  
  Please provide samples and a file with sample number and name.
• Quality control
  Carm-2 and CaCO3-merck.

• Analysis
  13C, 15N, 34S, 2H (and 18O) of solid samples (soil, sediment, plant etc.)
  
• Sample Preparation
  Note: Before use clean utensils using ethanol and Kimwipes, allow to dry!
  Sediment, soil and organic material
  Note: Carbonatic sediments need to be analyzed using two preparation pathways for CNtot and Corg!
  Sample Quantities:
  Organic materials 1–2mg Sediment 5–40mg
  
  • CNtot analysis
  Samples should be dried/freeze-dried and homogenized.
  Weigh a quantity of material in tin capsules 5x8mm (1–20mg) or silver
  capsule 6x6x12mm (more than 20mg), seal and place the samples into a sample tray.
  
  Use the sample sheet provided, fill in the sample sheet with sample ID and weight.
  
  • Corg analysis
  Samples should be dried/freeze-dried and homogenized.
  Weigh a quantity of material in silver capsules 6x6x12mm and add a few drops of 2N HCl (should cover all material).
  If reaction occurs, i.e. bubbles are created, dry the sample for 1h at 60 degrees and repeat the addition of acid.
  Dry overnight at 60 degrees.
  Seal the capsule and place them in a sample tray.
  Use the sample sheet provided, fill in the sample ID and weight.

• GFF filter samples
• Corg, N analysis
  Add the wet filters in a desiccator with conc. HCl overnight.
  Dry them in a desiccator with bluegel at 60 degree overnight.
  Pack them in silver boats 6x6x12mm and put them in a sample tray.
  Use the sample sheet provided, fill in the sample ID and weight.
• Quality control
  IVA High Organic Sediment, IVA Low organic soil, IVA Acetanilide.
  

• Analysis
  Elements in groundwater, porewater, seawater or extractions in solution can be analyzed. The ICP-OES can analyses most of the elements in the periodic table. Carbon, nitrogen, hydrogen, oxygen and halogens cannot be determined using this technique.
• Sample preparation
  The range of detection capability of the instrument is from 1 ppb to 100 000 ppb. The detection limit varies for different elements, ideal ranges for analysis are between 10–1000 ppb. Depending on the concentration of elements in your solution and which of these elements you are targeting, you may have to dilute your samples.
  
  In general groundwater, lake and river water do not need to be diluted.
  Seawater need a dilution factor of 1000 for analyses of major elements (e.g. Na), and for trace elements 100. It is the high concentration of Na in seawater that has to be diluted to an acceptable level for the instrument so it doesn’t create interference (Na max. 100 000 ppb).
  
  For other types of water, the dilution factor will depend on the concentration of elements in the solution.
  The samples also need to be acidified with HNO3 (1–3%). This should be done at the sampling site or directly after sampling. If you dilute the samples, continue to keep the HNO3 concentration at 1–3%.
  
  For performing the analyses, you need to prepare at least 5 ml of sample. We supply you with the tubes for the analyses. The samples should “rest” at least 24 hours between preparation and analysis.
  
  If you want to do elemental analyses:

1. Contact Kasun, kasun.gayantha@geo.su.se to check if dilution of the samples is necessary, and which elements you are targeting (major or trace elements).
2. Acidify your samples (HNO3, 1–3%).
3. Prepare at least 5 ml of sample.
4. Label the tubes 1, 2, 3 ….. etc. with a permanent marker (no sample name on the tubes). Keep track of label number on tubes and the real sample name (on a file).

• Quality control
  NIST1643f and internal controls

• Analysis
  18O and 2H of water
  
• Sample preparation
  The samples should be stored in a fridge or cooling room between sampling and analysis.

1. Fill the vials (1.5 ml or 2 ml) so that there is a small air bubble. Close them (blue screw cap, PTFE/SILICONE/PTFE septum).
2. Label the vials 1, 2, 3 ….. etc. with a permanent marker (no sample name on the vials). Keep track of label number on vials and the real sample name (on a file).

• Quality control
• The instrument is calibrated to the international scale standard via VSMOW and SLAP. We use a series of in-house reference waters measured against WSMOW and SLAP when we run samples. Standard deviations are ±0.1‰ for δ18O and ±0.6‰ for δD