Use of direct immersion solid-phase microextraction on polyacrylate and polydimethylsiloxane stationary phases for simultaneous determination of the neutral and basic pharmaceuticals in wastewater

摘要

Direct immersion solid-phase microextraction has been optimized and applied to the simultaneous determination of the neutral and basic pharmaceuticals: caffeine, carbamazepine, clomipramine, chlorprothixene and clotrimazole at low concentrations in municipal wastewater. Two absorption type stationary phases: polydimethylsiloxane (PDMS) and polyacrylate (PA) have been found to be most effective for extraction of target analytes. The separation and detection were carried out by gas chromatograph coupled with mass spectrometer working in the selected ion monitoring mode. The method was validated for linearity, detection and quantitation limits, selectivity and precision. The average correlation coeffcient of the calibration curves was 0.9933. The LOD values in infuent and effuent wastewater were in the range of 10-145 ng L~(-1) and 4-111 ng L~(-1) , respectively, which were a bit higher than those in the deionized water due to matrix effect. The high values of distribution coeffcient (K_(fs) ) in PDMS/water and PA/water systems (log K_(fs) between 3.05 and 4.23) indicates the very high applicability of these stationary phases for determination of carbamazepine, clomipramine, chlorprothixene and clotrimazole in water samples.