Loss on Ignition Method

What are the official methods of moisture content determination?

The Loss on Ignition (LOI) method is an official method used to determine the moisture content of a sample by heating it at a high temperature in a furnace, under controlled conditions, and then measuring the difference in mass between the original sample and the sample after heating.

How is the LOI method performed?

• A known mass of the sample is placed in a crucible and heated in a furnace at a temperature between 450°C and 600°C for several hours.
• During heating, any moisture present in the sample will vaporize and be driven off.
• The sample is then removed from the furnace and allowed to cool in a desiccator.
• Once cooled, the sample is weighed again, and the difference in mass between the original sample and the sample after heating is determined.

What are the advantages and disadvantages of the LOI method?

Advantages:

• The LOI method is relatively simple and inexpensive to perform.
• It can be used to determine the moisture content of a wide variety of materials.
• It is a direct method, which means that it does not require the use of calibration standards.

Disadvantages:

• The LOI method can be destructive, as the sample is heated to a high temperature.
• The method can be time-consuming, as it can take several hours to complete.
• The method is not as accurate as some other methods of moisture content determination.