Methods and Techniques - Soils and
Sediments - Loss-on-ignition
- Ball, D. F. 1964
- Loss-On-Ignition as an Estimate of Organic Matter and Organic
Carbon in Non-Calcareous Soils.
Journal of Soil Science 15(1):84-92.
Ball describes the "usual procedure" for LOI
as ignition of an oven-dried sample in a muffle furnace of half
hour at 850°C. He notes that this procedure does not attempt
to distinguish what component of the sample is contributing to
weight loss. He indicates that "elemental C" (i.e., contained in
coal or charcoal or other carbonized material) is destroyed at
ignition temperatures of 375° and 850°C. He cites older
work (Keeling 1962) that shows that heating at 375°C for 16
hours removes "carbonaceous material" without loss of structural
water from clays. He states that the greatest loss of water from
clays occurs in temperature range 450°C to 600°C. He
tested low temperate ignition using non-carbonate-rich soils.
Concluded that accuracy (as measured against chemical
digestion/titration procedures for organic C) was better for the
lower temperature ignition (375°C). States that this
"must be maintained for a much longer time than the 850°C
ignition". However, there are no data presented to justify the
- Beaudoin, A. 2003
- A Comparison of Two Methods for Estimating the Organic
Journal of Paleolimnology 29(3):387-390.
AEU SCI QE 39.5 P3 J86
- Bengtsson, L., and M. Enell 1986
- Chemical Analysis.
In Handbook of Holocene Palaeoecology and
edited by B. E. Berglund, pp. 423-451. John Wiley & Sons,
Chichester, England, UK.
AEU SCI QE 741 H236 LOI procedure is
on pp. 426-428. Oven-dry sample at 105°C for at least 12
hours, 550°C ignition for a minimum of 2 hours, 925°C
ignition for minimum of 4 hours. They note that the crucible
be ignited in furnace at 550°C for 1 hour before procedure
begins. They also note that in highly organic samples, the
may need to have a lid on to prevent loss through ash drifting
crucible. (This would probably limit oxygen to the sample and
reduce combustion rate). They also note that, if the sample is
still black after 2 hours of 550°C ignition, then combustion
is incomplete. They recommend igniting for a further 30 minutes,
after a chemical treatment of the cool residue with "1 or 2
of 20 g/100 ml w/v NH4NO3 (ammonium
solution. They indicate that the values given by LOI provide an
approximation for organic matter in the sample. They also make
caveats about calcareous samples.
- Dean Jr, 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(1):242-248.
AEU SCI QE 420 J86 States that OM begins to
break down at 200°C, ignition complete by 550°C.
Breakdown of calcium carbonate to release CO2 by
850°C, though dolomite breaks down at 700 - 750°C.
recommended procedure therefore is: oven-drying sample overnight
(so all computations are done on an oven-dry basis - the standard
for oven-drying is 105°C). Muffle furnace for 1 hour heated
500°C (weight difference gives OC). Muffle furnace for 1
heated to 1000°C (weight difference gives measure of
minerals). He points out that clay minerals contain interstitial
water, and therefore part of the high-temperature weight loss
be due, not to carbonate breakdown, but to loss of water from
clays. This can be significant where clays are a large component
the sample (e.g., in many lake sediments).
- Heiri, O., A. F. Lotter, and G. Lemcke 2001
- Loss on Ignition as a Method for Estimating Organic and
Carbonate Content in Sediments: Reproducibility and Comparability
Journal of Paleolimnology 25:101-110.
AEU SCI QE 39.5 P3 J86
- Keeling, P. S. 1962
- Some Experiments on the Low-Temperature Removal of
Material from Clays.
Clay Minerals Bulletin 28:155-158.
Describes experiments to distinguish the
weight loss on ignition due to "carbonaceous material" to that
clay minerals. Notes that clay minerals show little breakdown
400°C. Showed that around 90% of carbon was removed after
heating at 375°C. This only applies if the clays are not
carbonate-rich. Samples were left in the furnace for 16 hours.
However, there is no discussion of why 16 hours was the optimum
time, just that the samples were heated overnight.
- White, E. M., and L. A. Hannus 1981
- Approximate Method for Estimating Soil Charcoal Contents.
Communications in Soil Science and Plant Analysis
Describes a method for estimating the
content of "soil" or sediment, especially applicable to
archaeological sites where charcoal can be significant component.
Point out that it may be difficult to tell is a "soil" layer is
black because of soil OM or because of finely-divided charcoal.
Treatment with hydrogen peroxide (H2O2) is
used to remove soil OM. However, peroxide does not remove
Their method also recommends a pretreatment with 4 N HCl to
"soluble compounds that might react with" peroxide (presumably
would be carbonates, both primary and secondary), and a post
treatment with 48% HF acid to remove silicates. (NB: HF is an
extremely hazardous material!) The water-washed residue (on a
filter paper) is weighed then ignited in a muffle furnace.
content is estimated by the weight loss. The paper does not
indicate the temperature or length of time of ignition.