ISO 18127 / EN ISO 18127:2026 Water quality — Determination of adsorbable organically bound fluorine, chlorine, bromine and iodine (AOF, AOCl, AOBr, AOI) — Method using combustion and subsequent ion chromatographic measurement

DIN EN ISO 18127 describes methods for the determination of adsorbable organically bound fluorine (AOF), chlorine (AOCl), bromine (AOBr), and iodine (AOI) in water samples. The standard is based on a combination of oxidative pyrohydrolytic combustion and ion chromatographic detection, commonly referred to as Combustion Ion Chromatography (CIC). Combustion and ion chromatographic analysis may be performed either as a coupled online procedure or as separate analytical steps. The parameters AOF, AOCl, AOBr, and AOI are determined by converting organically bound halogens into the corresponding hydrogen halides, followed by their quantification using ion chromatography.

The relevance of these parameters lies in their potential impact on both the environment and human health. Organically bound halogens can enter the aquatic environment from industrial processes, consumer products, pesticides, flame retardants, pharmaceuticals, and other anthropogenic sources. Many of these compounds are characterized by high environmental persistence and may accumulate in organisms and environmental compartments.

Organochlorine compounds, for example, are well known for their persistence and environmental significance. Organobromine compounds, widely used as flame retardants, are also of increasing interest in environmental monitoring. Organofluorine compounds, including per- and polyfluoroalkyl substances (PFAS), have gained global attention due to their exceptional stability and persistence. Because they remain in the environment for very long periods, they are often referred to as “forever chemicals.” 

In contrast to targeted analytical methods the sum parameter described in ISO 18127 quantify not only selected compounds, they provide information on entire substance groups, including unknown or currently unregulated compounds. As a result, the method is well suited as a screening tool for evaluating the overall halogen-related contamination of a sample. The standard therefore represents an important tool for environmental monitoring, risk assessment, and regulatory compliance, contributing to the protection of both environmental and public health.

The ICprep family of Analytik Jena enables the sample preparation for determination of adsorbable organic halogens (AOF, AOCl, AOBr, AOI) in water and sludge. Together with the APU series systems for AOF columns adsorption we offer a great solution to get from sample to the IC-ready absorption solution, which can be introduced into any suitable ion chromatograph.

Sources

• ISO 18127 - Water quality — Determination of adsorbable organically bound fluorine, chlorine, bromine and iodine (AOF, AOCl, AOBr, AOI) — Method using combustion and subsequent ion chromatographic measurement