Total Dissolved Solids in Water Definition
The total concentration of dissolved substances or minerals in natural waters is a useful parameter in describing the chemical density as a fitness factor, and as a general measure of edaphic relationships that contribute to productivity within the body of water. Total dissolved solids (TDS) are determined by simply evaporating a filtered quantity of water at low temperatures. The dried residue contains both inorganic and organic materials. Ignition of this residue at high temperatures eliminates the volatile substances usually organic in nature and decomposes bicarbonates with the loss of carbon dioxide. The residue following ignition therefore contains the total dissolved inorganic solids. The difference between it and the original residue being termed the loss on ignition. The amount of residue in each operation and the loss on ignition is expressed as a proportion of the original water sample in terms of milligrams per liter (mg/L).