In chemical terms, dioxins are the general names of compounds that are linked by two oxygen bridges and have two chlorinated benzene rings. PCBs (polychlorinated biphenyls) are organic compounds composed of chlorine atoms bound to biphenyl, a molecule consisting of two benzene rings.

Dioxins are not naturally present. Dioxins are formed when organic substances are burned above 200 in an environment with chlorine. There are various dioxin sources. For example, waste incineration plants, disposal of medical and domestic wastes, thermal power plants, petrochemical industry activities, cement factories. The sources that make up PCBs are: PVC coating, anti-combustible mixtures and wood building materials for stabilizing electrical cables and electronic materials. As a result, PCBs are man-made, but production is prohibited on 1970s.

Many analysis methods are used in the determination of dioxin. HR-GCMS analysis method is one of the best methods for determination of dioxin source.

The Ministry of Food, Agriculture and Livestock of the Turkish Food Codex 2015 year in certain foods, dioxins, dioxin-like polychlorinated biphenyls and non-dioxin-like polychlorinated biphenyls for the official control of the level of sampling, sample preparation and analysis method criteria (Communiqué no: 2015) published. This communiqué regulates criteria for sampling and analysis of foodstuffs to control the level of dioxins and furans present in certain foods, dioxin-like polychlorinated biphenyls (PCBs) and non-dioxin-like PCBs.

In the said communiqué, it is stated that verification methods will be used to clearly identify and calculate dioxins and dioxin-like PCBs in foodstuffs such as feedstuffs, fats, meat, milk and fish. GC-HRMS analysis is included in the validation method.

In the authorized laboratories, the total of dioxins, total of dioxins and dioxin-like PCBs and total of indicator PCBs are analyzed by GC-HRMS method within the scope of chemical tests.