Organic Matter: Loss on Ignition

GSI Protocol #01
Published: August 19, 2022
Revised: June 1, 2023
Prepared by: Stephen G. Hesterberg, Ph.D., Executive Director; Sarah W. Hutchins, M.S., Staff Scientist

MATERIALS

• Porcelain crucibles (10-25 mL)

• Kim wipes or dry brush

• Microbalance

• Latex gloves

• 10 mL syringe (tip removed)

• Muffle furnace or kiln

INSTRUCTIONS

1. Clean crucibles with soap and water, a dry brush, or compressed air before use.

2. Pre-weigh each crucible with a microbalance.

3. Use a 10 mL syringe to take a consistent 3 mL of sediment and place into a crucible.

4. Dry crucibles at 60°C until constant weight (± 0.01 g).

5. Combust samples in a muffle furnace or kiln at 550°C for 5 hours. Create a map of sample location in the furnace/kiln. Re-weigh crucibles on microbalance after cooling in a desiccator and calculate % SOM (Davies 1974).

6. Combust samples in a muffle furnace or kiln at 900°C for 5 hours. Create a map of sample location in the furnace/kiln. Re-weigh crucibles on microbalance after cooling in a desiccator and calculate %CaCO3 (Dean 1974).

REFERENCES

Davies, B. E. (1974) Loss on Ignition as an Estimate of Soil Organic Matter. Soil Science Society of American Proceedings 38: 150–151.

Dean, W. E. (1974) Determination of Carbonate and Organic Matter in Calcareous Sediments and Sedimentary Rocks by Loss on Ignition: Comparison with Other Methods. Journal of Sedimentary Petrology 44:242–248.