Photolytic Spectroscopic Detection of Herbicides and BTEX in Water

Abstract

Fast, sensitive and selective determination of low levels of important contaminants of raw waters used for drinking water supplies has been demonstrated. We use on-line ultraviolet (UV) absorption spectroscopy in the wavelength range 200–400nm performed within a low-power, in-situ, photochemical reactor. Depending on the photolytic source’s peak photon energy and the species to be detected, the photochemical effects include simple reduction of UV-absorbance, as well as the generation of species absorbing at different UV wavelengths. This double spectral signature, together with multivariate linear spectral analysis, allows excellent selectivity in real samples with minimal sample preparation.