ISO/DIS 24295:2024

This document specifies a method for the determination of the dioxin-like activity of water and wastewater by means of an AhR-mediated reporter gene assay utilizing stably transfected mammalian cell line. This reporter gene assay is based on the activation of the mammalian AhR signalling pathway. This method is applicable to: — drinking water; — fresh water; — groundwater; — river water; — wastewater. The limit of quantification (LOQ) at CV 20 % or less of this method is 0,5 pg and 1,0 pg 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) equivalents (TCDD-EQ)/l based on the results of laboratory trials using appropriately extracted and cleaned up water samples for dioxins and dioxin-like compounds in rat and mouse cell lines, respectively. The LOQ depends on the sample volume. For determination of TCDD-EQ derived from dioxins and dioxin-like compounds in water and wastewater, suitable extraction and clean-up are necessary for water samples, since AhR ligands/agonists are composed of a wide variety of structurally diverse compounds including natural, and anthropology-natural substances. NOTE In this document, TCDD-EQ is used instead of TEQ which represents toxicity equivalent quantity.