TRACE-LEVEL DETERMINATION OF AROMATIC SULFONATES IN WATER BY ONLINE ION-PAIR EXTRACTION ION-PAIR CHROMATOGRAPHY AND THEIR BEHAVIOR IN THE AQUATIC ENVIRONMENT

A new HPLC method for the fully automatic determination of aromatic su lfonates in aqueous samples is presented. The analytical procedure con sists of an on-line combination of ion-pair extraction (IPE) and ion-p air chromatography (IPC), both using RP-C18 solid-phase material and a tetrabutylammonium salt as ion pairing reagent. Experimental details and performance data are given. This method is suited for the trace-le vel determination of a wide variety of benzene, naphthalene, anthraqui none and stilbene sulfonates. Detection limits for surface water using a diode-array detector are in the sub-ppb range. For naphthalene sulf onates a very good selectivity and minimal detectable limits of 0.02 m u g/L or even lower can be achieved. So far, this method has been succ essfully applied to waste water, river water, bank filtrate, and water from different steps of drinking water production. The fate of severa l aromatic sulfonates has been studied beginning at the effluents of i ndustrial waste water treatment plants and ending after activated carb on filtration in a water works. Napthalene-1,5-disulfonate (NDS, Armst rong acid) and cis-4,4'-dinitrostilbene-2,2'-disulfonat (DNS) appear i n the raw water of the investigated water works and therefore have to be termed as relevant to water works. In contrast to other disulfonate s NDS is extremely stable to biodegradation and ozonation and it is ev en desorbed from a highly loaded activated carbon filter.