Loss on Drying (Percentage Dry Weight)

The percentage weight loss when sediment is dried is determined by the sediment composition. Generally sediments with a high organic content weigh less when dried than an equivalent wet weight of sediment with a high mineral content.

Equipment

Clean, dry porcelain crucibles, spatula, balance weighing to at least 3 decimal places, oven or furnace set to 105°C, desiccator.

Procedure

Weigh an empty crucible to 3 decimal places. Add between 1 and 2 grams of wet sediment being careful to keep sediment away from the rim of the crucible where it may become dislodged and fall out during handling. Re-weigh crucible and place in the oven for at least 12 hours or overnight. Using tongs, remove the crucibles from the oven and allow to cool in a desiccator (to prevent re-absorption of moisture) before re-weighing. The percentage weight remaining after drying can then be calculated. The same sample can also be used for loss on ignition analysis.