Solid-phase microextraction (SPME) in gas chromatography-mass spectrometry (GC-MS) has been introduced as a rapid and sensitive quantitative method for the detection of some aniline derivatives (o- toluidine, p-chloroaniline, 2,4-di-chloroaniline, 2,5-dichloroaniline, 3,4- dichloroaniline and 3,5-dichloroaniline) in environmental water samples. Many parameters for optimisation of the extractive method, such as linearity, sensitivity, equilibration time, precision, and different operating conditions (pH, salt) have been evaluated. After a comparison of the commercially available SPME fibers, a carbowax-divinylbenzene 65 μm polymeric phase was chosen. Linearity was excellent in the concentration range 0.05-5 μg/l, and the method showed good reproducibility (coefficient of variation of around 5%). The detection limits differ substantially for the various compounds analysed, but all were below any other limit of detection for these compounds in the literature. The addition of salt (sodium chloride) at pH 7.6 significantly improved the amount of analytes extracted by the fiber. Operating under basic conditions (pH 11), we did not observe a better sensitivity of the method. To evaluate its applicability on a real aqueous matrix, various groundwater samples collected in an industrially polluted area north of Milan, Italy, were analysed.
ASJC Scopus subject areas
- Analytical Chemistry