TOC stands for Total Organic Carbon in English and stands for total organic carbon. TOC measurements mean the measurement of organic substances in a water system, ie carbon-based impurities. One of the water analysis methods used in various water plants, feed water, water purification and distribution units is total organic carbon measurements.

The method applied to total organic carbon measurements is the catalytic combustion of organic matter in water at high temperatures and the conversion of carbon dioxide into gas. The amount of carbon dioxide gas released in this way is measured and the total amount of organic carbon present in the water sample is determined.

Substances containing organic compounds are called organic substances and are not naturally present. The main organic materials are petroleum, PVC glue, alcohol, sugar, sucrose and plastic-based derivatives. These organic substances are synthesized during the metabolic activity of the organism. Organic materials can be mixed in water during filtration or produced by bacteria that form in water.

In the issued regulations, the total amount of organic carbon also includes volatile organic compounds known as VOCs. Therefore, in testing and measurement studies, competent laboratories are based on two standards:

• TSE CEN / TS 13649 Constant source emissions - Determination of the mass concentration of each gaseous organic compound - Solvent extraction or thermally monitored sorptive sampling method
• TS EN 12619 Constant source emissions - Determination of the mass concentration of total gaseous organic carbon at low concentrations in flue gases - Continuous method using flame ionization detector

Organic carbon content (TOC) measurements are important for human health. These measurements are carried out by authorized test and inspection institutions. During the measurements, legal regulations in force and standards published by domestic and foreign organizations are taken into consideration. A few standards considered in this context are:

• TS EN ISO 7827 Water quality - Determination of ready, final aerobic biodegradability of organic compounds in aqueous media - Dissolved organic carbon (TOC) analysis method
• TS EN 15936 Sludge, treated bio waste, soil and waste - Determination of total organic carbon (TOC) by dry combustion
• TS EN 16718 Wood and wood based products - Total organic carbon (TOC) dosage in wood and wood based products
• TS 12089 EN 13137 Properties of wastes - Determination of total organic carbon (TOC) in waste, sludge and sediments

In short, a lot of water is consumed in many processes in various sectors. This consists of a large amount of wastewater. Determination of the chemical properties of these waters is important for the establishment and operation of an efficient treatment plant. In this context, the pH value of water, the amount of dissolved oxygen in the water and turbidity of the water as well as the organic loads in the water is expected to be determined.