AOX (AOX – absorbable organically bound halogens) is an analytical convention which represents the sum of all organically bound halogens (except fluorine), mainly used in water and waste water analysis. Solid samples like sludge or sediments can also contain AOX. The solid AOX however has to be determined by the batch method which is not part of this application. The compounds containing halogens are adsorbed onto the surface of activated carbon (charcoal) in dissolved or suspended form. The activated carbon is washed afterwards with aqueous nitrate washing solution to remove inorganic halides. During the combustion of the loaded charcoal in pure oxygen at high temperatures hydrogen halides are formed. After absorption of the halides the final detection takes place inside a coulometric cell by means of argentometric titration.