CORRELATION AND DIGITAL SIGNAL-PROCESSING TECHNIQUES FOR THE REDUCTION OF DETECTION LIMITS OF BROMATE AND BROMIDE IN MODEL WATER SAMPLES BYION CHROMATOGRAPHY WITH DIRECT ULTRAVIOLET DETECTION

Bromate is a well known by-product produced by the ozonation (disinfec tion) of drinking water, of which the concentration is considered to b e regulated to a low mu g/l level, Successful ion chromatographic meth ods of determination involve the implementation of concentration colum ns. As an alternative to concentration, it is demonstrated that the lo w mu g/l level can easily be attained using a simple and foolproof exp erimental arrangement of direct pseudo random injections of large quan tities of the sample and ultraviolet (UV) detection at 204 nm with sub sequent decorrelation of the detector signal. The approach, known as c orrelation chromatography, makes high demands to the reproducibility a nd other properties of the injection system. Although correlation chro matography is less sensible to spikes and baseline drift compared with normal chromatography, optimum results will be achieved by applying d igital detector processing prior to decorrelation, combined with a pro per modification of the eluent. This is demonstrated here. (C) 1997 El sevier Science B.V.