STANDARD TEST METHODS FOR PARTICULATE AND DISSOLVED MATTER, SOLIDS, OR RESIDUE IN WATER
|Publication Date:||28 April 1978|
These test methods cover the determination of particulate, dissolved, and total matter, sometimes referred to as the suspended, dissolved, and total solids, in water. Two procedures consistent with the total matter content, are provided.
The test methods actually cover the determination of (1) the constituents of water that can be removed by filtration, and (2) the residue on evaporation to dryness of either filtered or unfiltered samples; as a result, they do not always measure water components as defined. Separation of particulate matter by filtration requires precise definition of the filtering medium since some materials that are in no sense dissolved, for example, certain colloids, may not be removed by the filter used. Secondly, an evaporation residue will usually differ in composition from the particulate and dissolved matter present in the water.
When particulate matter is determined separately (the sample is filtered and the residue quantitatively assessed), provision is made for the use of either a membrane filter that will remove all particles over 0.45 μm in size or an asbestos fiber medium in a Gooch crucible. However, unless otherwise specified when results are reported, use of the membrane filter shall be assumed. It is further provided that all buoyant floating particles or large particulate agglomerations that cannot be dispersed throughout the sample by vigorous shaking need not be considered as fundamental constituents of the water under examination and may be excluded, therefore, from the test portion.
The test methods include steps for the determination of volatile matter in the dry residue from either filtration or evaporation. They do not. however, cover water constituents that are (1) volatile at the boiling temperature, or (2) normally classified as "oily matter," which is extractable with organic solvents or volatile at the drying temperature of filtration residues. For the determination of the latter, refer to Test Method 0 2778.