DETERMINATION OF VOLATILE ORGANIC-COMPOUNDS IN WATER INTAKES AND TAP WATER BY PURGE-AND-TRAP AND DIRECT AQUEOUS INJECTION-ELECTRON CAPTURE DETECTION TECHNIQUES

Two methods for the determination of volatile organic compounds in wat er intakes and tap water were applied. For the determination of volati le hydrocarbons (heptane, xylene, toluene, benzene, isooctane, nonane, decane, undecane) and chlorobenzene, the purge-and-trap technique, so rption on a solid sorbent, thermal desorption and gas chromatography w ith flame ionization detector for the final determination were applied . The detection limit of this method was about 0.05 mu g l(-1). For th e determination of trihalogenomethanes, trichloroethylene and carbon t etrachloride, direct aqueous injection into a capillary column (DB-1) and electron-capture detection (ECD) were used. The detection limits o f the method, dependent on the species being determined, was estimated at 0.01 mu g l(-1) on average. The methods have been used for the det ermination of volatile hydrocarbons and organohalogen compounds in the water intakes for Gdansk (8 underground intakes, one surface water in take from Radunia River, and one drainage intake at Pregowo). Trihalog enomethanes were determined also in the tap water from different distr icts of Gdansk.