An analytical method was developed for the analysis of sucralose, a persistent chlorinated calorie-free sugar substitute, in surface waters. The method is based on solid-phase extraction (SPE) of 400mL water using Oasis HLB (Waters) adsorber material, followed by negative electrospray ionization (ESI) triple quadrupole LC-MS-MS detection. Quantification was performed by external calibration, as well as by isotope dilution with deuterated sucralose d6 internal standard. Extraction with Oasis HLB, a polymeric adsorbent suited for polar compounds, was much more efficient at neutral pH than at pH 3; a recovery of 62+/-9% (n=6; determined at 1microg/L) could be achieved. Strong ion suppression caused by matrix substances was observed for sucralose in the SPE extracts. The analysis of 120 river surface water samples from 27 European countries showed that sucralose, which is in use in Europe since beginning 2005, can be found in the aquatic environment, at concentrations up to 1microg/L. Sucralose was predominately found in samples from the UK, Belgium, the Netherlands, France, Switzerland, Spain, Italy, Norway, and Sweden, suggesting an increased use of the substance in Western Europe.