A very fast and simple method for the determination of sulfonamide residues in seawaters

The development of simple and reproducible analytical methods for the determination of new organic pollutants like pharmaceuticals and personal care products in seawaters is of the highest priority. In the present study, a new analytical method based on offline solid phase extraction and liquid chromatography with standard UV detection (SPE-FIPLC-UV) was developed to determine the presence of sulfonamides in seawaters. Special attention was paid to the sample preparation step. Different variables affecting the extraction process, such as seawater salinity and the humic acid content were studied. As a result, the presented SPE procedure for the extraction of sulfonamides from seawaters is also applicable to other techniques like LC-MS and LC-MS/MS. This method was optimized and fully validated for its performance parameters. It has very good selectivity, linearity (R(2) > 0.995), precision (RSD < 5%), accuracy (76.7-115.4%), as well as low limits of detection (LOD, 167 ng L(-1)) and quantification (LOQ, 500 ng L(-1)). This SPE procedure proved to be very effective (absolute recovery >75%), even in highly saline waters and in the presence of humic acids.