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A surface-imprinted chiral stationary phase for the enantiomeric resolution of the antidepressant drug, citalopram, is presented in this work. N, N′-diethylaminodithiocarbamoylpropyl(trimethoxy)silane has been used as silane iniferter for the surface functionalization of the solid silica support. A molecularly imprinted polymer thin film, in the nm scale, was then grafted on the silanized silica using itaconic acid as the functional monomer and ethylene glycol dimethacrylate as the cross-linker in the presence of the template S-citalopram. The total monomer amount was calculated to obtain the desired thickness. Non-imprinted stationary phases were prepared similarly in the absence of S-citalopram. Characterization of the materials was carried out by scanning electron microscopy, thermogravimetric analysis, elemental analysis and Fourier transform infrared spectroscopy. Stationary phases have been applied to the chromatographic separation of the target. Conditions for best chromatographic resolution of the enantiomers were optimized, and it was found that a mobile phase consisting of a mixture of formate buffer (40 mM, pH 3) and acetonitrile (30:70 v/v) at 40 °C provided best results. Binding behaviour of the developed material was finally assessed by batch rebinding experiments. The obtained binding isotherm was fitted to different binding models being the Freundlich-Langmuir model, the one that best fitted the experimental data. The developed material has shown high selectivity for the target enantiomer, and the stationary phase could be undoubtedly exploited for chiral separation of the drug. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this article is to present a new procedure based on dual solid-phase microextraction (dSPME) for the simultaneous extraction of 16 pharmaceutical compounds with acidic and basic characteristics in urban wastewaters. Water samples are divided into two aliquots of 2mL each extracted by two CW-TPR fibers at different pH values (pH 3 and 11) and with a NaCl concentration of 300gL−1 at 75°C for 30min. The analytes in both fibers are desorbed one after the other in the desorption chamber in static mode with mobile phase for 10min. The extracts are injected into an LC system coupled to an ion trap mass spectrometer, leading to the accurate quantification of 16 pharmaceutical compounds in wastewaters, in MS2 mode. All the target compounds found in wastewaters provide good signals corresponding to the protonated precursor ion [M+H]+. The parameters influencing adsorption and desorption of the analytes on fiber were optimized. The assessment of the analytical method was performed by studying the linearity (LOQ to 10ngmL−1) and the intra- and interday accuracy (89.2–109.7%) and precision (RSD <13.6%). The quantification limits obtained ranged between 0.005 and 0.05μgL−1. The application of the method to real samples proves its effectiveness in identifying and detecting naproxen, valsartan, bezafibrate, torasemide, diclofenac, carbamazepine, citalopram, lorazepan, fluoxetine, imipramine and amitriptyline in influent and effluent wastewater treatment plant samples. [Copyright &y& Elsevier]

This paper reports the application of a chiral imprinted polymer (CIP)-coated stir bar for the selective extraction of (+)-(S)-citalopram (SCIT) and its main metabolites, (+)-(S)-desmethylcitalopram (SDCIT) and (+)-(S)-didesmethylcitalopram (SDDCIT), from urine samples. The developed device has been demonstrated to be capable of selectively extracting the three target analytes from urine samples without saturating the imprinted sites. A CIP-coated stir bar sorptive extraction procedure (CIP-SBSE) is proposed for the isolation of SCIT, SDCIT and SDDCIT followed by their subsequent analysis using liquid chromatography ion trap mass spectrometry (LC-ITMS). Deuterated SCIT-d6 was used as an internal standard. The method was validated using a standard procedure, which revealed that a quantification of 5 ng mL(-1) was obtained in urine samples and that the accuracy and precision were within the established values while no matrix effect was observed., (Copyright © 2013 Elsevier B.V. All rights reserved.)