Adsorbable organically bound halogens, also called adsorbable organic halogens (AOX), are the sum of halogenated organic compounds that are adsorbable on activated carbon. Many of these organic halogen compounds pose serious risks to human health and the environment. Therefore, AOX must be monitored to ensure adequate water quality as well as to trace its sources and investigate the efficiency of AOX removal techniques in water treatment processes.

Historically, this sum parameter was determined by titration as per DIN EN ISO 9562 or EPA 1650. However, these methods cannot individually determine the amount of adsorbable organically bound chlorine, bromine, and iodine (AOCl, AOBr, and AOI, respectively). The German standard method DIN 38409-59 describes a method using combustion ion chromatography (CIC) to determine AOCl, AOBr, AOI, and the sum parameter CIC-AOX_(Cl). Additionally, AOF can be determined which is a monitoring parameter for per- and polyfluoroalkyl substances (PFAS).

This White Paper covers the following topics:
 

• Introduction to the parameter AOX
• Advantages of combustion ion chromatography analysis compared to traditional methods
• AOF and AOX analysis according to DIN 38409-59 including sample preparation