HPLC determination of chlorobenzenes, benzenesulphonyl chlorides and benzenesulphonic acids in industrial waste water

An HPLC method has been developed for the determination of chlorobenzenes, benzenesulphonyl chlorides, benzenesulphonic acids and related compounds in industrial waste water The separation and determination of diphenylsulphon e, 1,4-dichlorobenzene, 1,2,3,4-tetrachlorobenzene, 1,2,3,5-tetrachlorobenz ene and pentachlorobenzene was performed in reversed-phase system with octa decylsilica gel stationary phase and aqueous-methanolic mobile phase. Succe ssful separation of ionic and polar compounds as water pollutants such as: benzenesulphonamide, benzenesulphonic acid, 1,3-benzenedisulphonic acid, 4- chlorobenzenesulphonic acid, 2,5-dichlorobenzenesulphonyl chloride, 2,3,4-t richlorobenzenesulphonyl chloride and 2,4,5-trichlorobenzenesulphonyl chlor ide requires addition of a salt (sodium sulphate) to the mobile phase. Addi tion of a buffer or of an ion-pair reagent to aqueous-methanolic mobile pha ses did not yield satisfactory improvement in separation selectivity nor of peak shape. Polar and ionic compounds, diphenylsulphone and chlorobenzenes , were separated and determined by a two-step, reversed-phase LC method. On -line sample enrichment on an adsorption column packed either with octadecy l silica or with aminopropyl silica connected to an LC column improved the limits of detection of the pollutants.