On-line solid-phase extraction-short-column liquid chromatography combinedwith various tandem mass spectrometric scanning strategies for the rapid study of transformation of pesticides in surface water

The applicability of solid-phase extraction-short-column liquid chromatogra phy using two short columns (i.e., 10 and 20 mm long) coupled on-line with tandem mass spectrometric detection is demonstrated for the rapid degradati on study of pesticides and their transformation products in water at the lo w-mu g/l level. Photolysis was used as a means to transform the parent comp ounds into their degradation products and the experiments were carried out at environmentally relevant concentrations. The use of on-line sample enric hment/separation in photodegradation studies allows the rapid analysis of a queous samples directly after irradiation without further transformation of the compounds of interest. The versatility of MS allows various selective screening strategies to be employed, i.e., full-scan mode, neutral loss, pr ecursor-ion and product-ion scan modes. This allows the identification of p ossible degradation products and the calculation of the rates of disappeara nce of the parent compound and appearance of transformation products. (C) 1 999 Elsevier Science B.V. All rights reserved.