By total suspended solids it is meant the sum of the collapsible and non-collapsible substances in the water sample. In general, sediment substances in water, rock and soil particles, mud or clay minerals, organic matter particles and plankton. Humans also increase the amount of solids present in surface waters through various activities. In addition, erosion in agricultural areas increases the amount of solids. The higher the total solids content, the more physically polluted the waters are. In this case, water becomes cloudy, condenses, poisoning properties increase, light transmittance and oxygen content decreases and damages water organisms. The degree of action of the solids varies according to the type, amount, size and species of the living things in the water.

The amount of solid is the weight of the filtrate residue filtered through standard glass fiber filter paper brought to constant weight and dried at 103-105 degrees. If the solids clog the filter during this test and the filtration time starts to prolong, the difference between total solids and total dissolved matter at this point gives the total solids amount. After 105 degrees, carbon dioxide starts to fly and turns into bicarbonate carbonate. Loss of organic matter decreases with evaporation.

In order to detect the evaporation residue, a well stirred sample of water is evaporated in a tube weighing constant. The 103-105 is then dried to a constant weight. The weight increase of the empty tube refers to the total amount of solids, ie the evaporation residue.

Total solids (evaporation residue) determination studies are carried out in authorized laboratories within the scope of chemical food analyzes. In these studies, standards and test methods published by domestic and foreign organizations are followed. The standard used in this respect is:

• TS 266 Waters - Waters for human consumption