The extraction performance of methacrylic acid-trimethylolpropanetrimethacrylate solid-phase microextraction fibers in aqueous solutions

The extraction performance of solid-phase microextraction fibers, based on methacrylic acid-trimethylolpropanetrimethacrylate (MAA/TRIM) copolymers, was investigated in aqueous Solutions using triazines as target analytes and 2-bromobiphenyl as a reference compound. The results revealed that the combination of electrostatic forces and hydrophobicity was the primary interaction between the MAA/TRIM coating and the triazines. To improve the selectivity of the MAA/TRIM-coated fiber for the triazines, several experimental parameters including pH of the sample solution, washing step, organic modifier, and salt concentration were optimized so as to amplify electrostatic interaction and suppress the hydrophobic effect. To evaluate the practicability of the proposed method, samples with complex matrixes, including corn extract and sewage sludge, were extracted with a MAA/TRIM-coated fiber under the optimized conditions chosen. The results showed that the extraction efficiency for target analytes was not enhanced, but the matrix effect of the interfering compounds in the samples was effectively restrained and thus the selectivity was obviously improved. (C) 2009 Elsevier B.V. All rights reserved.