Loss on Ignition .
1 Scope-Loss on ignition LOI is the loss in weight expressed as percent of the initial "as received'' sample weight obtained after ignition of the sample at 1000°C to constant weight. The loss in weight is due to a release of free moisture, chemically combined "lattice" or "hydroxy" water, CO2, SO2, and volatile pyrolytic products of any organic material that may be present