Sample Weight: 2.5 g
Essential water is determined by drying the sample for 1 hour at 105±5°C to remove H2O¬ (hydroscopic water). Then the sample is heated at 950°C by using a tube furnace. The H2O+ expelled from the sample is absorbed by magnesium perchlorate. The gain in weight of the perchlorate is used to calculate the amount of combined water in the sample.
Non-essential water is determined by drying the sample for 2 hours at 105±5°C. From the loss in weight, non-essential water, in percent, is calculated.
The lower reporting limit is 0.1% for both forms of water.
Data will be deemed acceptable if recovery of Essential and Non-essential water is ±15% at five times the Lower Limit of Determination (LOD) and the calculated Relative Standard Deviation (RSD) of duplicate samples is no greater than 15%.
Central Mineral and Environmental Resources Science Center