DETERMINATION OF AROMATIC-AMINES BY SOLID-PHASE MICROEXTRACTION AND GAS-CHROMATOGRAPHY MASS-SPECTROMETRY IN WATER SAMPLES

Solid-phase microextraction (SPME) in gas chromatography-mass spectrom etry (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-dichloroaniline, 2,5-dichloroaniline, 3,4-dichloroa niline and 3,5-dichloroaniline) in environmental water samples. Many p arameters 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 c ommercially available SPME fibers, a carbowax-divinylbenzene 65 mu m p olymeric phase was chosen. Linearity was excellent in the concentratio n range 0.05-5 mu g/l, and the method showed good reproducibility (coe fficient of Variation of around 5%). The detection limits differ subst antially for the various compounds analysed, but all were below any ot her limit of detection for these compounds in the literature. The addi tion of salt (sodium chloride) at pH 7.6 significantly improved the am ount of analytes extracted by the fiber. Operating under basic conditi ons (pH 11), we did not observe a better sensitivity of the method. To evaluate its applicability on a real aqueous matrix, various groundwa ter samples collected in an industrially polluted area north of Milan, Italy, were analysed. (C) 1997 Elsevier Science B.V.