WAVELENGTH-RESOLVED LASER-INDUCED FLUORESCENCE DETECTION IN CAPILLARYELECTROPHORESIS - NAPHTHALENESULPHONATES IN RIVER WATER

Capillary electrophoresis (CE) is combined with wavelength-resolved la ser-induced fluorescence detection for the environmental analysis of n aphthalenesulphonates (NS) in river water samples. The method enables the detection and the identification of non- as well as hydroxy- and a mino-substituted NS. An approximate 30-fold sample concentration is pe rformed by off-line solid-phase extraction prior to the CE separation. The native-fluorescent NS are excited at 280 nm or 325 nm by an excim er dye laser combination providing tunable UV radiation. Wavelength-re solved fluorescence-emission spectra are recorded on line by an intens ified diode-array detector mounted on a spectrograph. Since the emissi on spectra are strongly affected by the type and pattern of substituti on, they provide much structural information. In combination with migr ation times identification is possible, if standards are available. Th e low to sub-mu g l(-1) detection limits achieved enabled the identifi cation and quantitation of two trisulphonate and an amino-disulphonate NS in River Elbe samples. The data obtained satisfactorily agree with those obtained by ion-pair HPLC.