Iron, gold, silver, sugar, salt, oxygen, mercury and similar substances in the structure of a single kind of substance. These are called pure substances. More than one pure substance can come together to form mixtures. When the substances form such a mixture, they do not lose their properties. Liquid, solid and gaseous materials may be present in a mixture at the same time. The substances in this mixture can be separated from one another and become pure again.

Disintegration of a substance into particles that are too small to be seen in another substance is called dissolution. These mixtures are called solutions. That is, a solution contains both soluble substances and soluble substances. For example, in a mixture of water and soda, water is the solubilizing agent, soda is the solubilizing agent.

Soils have been formed with the disintegration of rocks with millions of years of impact and the mixing of organic materials. Chemical, physical and biological activities played a role in this fragmentation. Today, this process continues.

Soil is the main source on which vegetation is fed. There are millions of living things in the soil the ecosystem is important for the continuation. The part that makes the soil fertile and rich in humus is the upper layer of the soil.

In terms of the structure of the soil, a normal soil consists of the following components: inorganic substances (45 percent), organic substances (5 percent), water (25 percent) and air (25 percent).

Accredited laboratories also measure total dissolved matter within the scope of soil and sewage sludge measurements. These studies are based on national and international standards and methods as well as relevant legal regulations. In the determination of total dissolved matter, the following methods are generally used:

• 5310B: Total Organic Carbon by High-Temperature Combustion Method
• TS 8195 EN 1484 Water quality - Total Organic Carbon (TOC) and Dissolved Organic Carbon (VER) Determination Guide
• SM 2540C Total Dissolved Solids