Solid-phase extraction of multi-class pharmaceuticals from environmental water samples onto modified multi-walled carbon nanotubes followed by LC-MS/MS

Abstract

In this paper, pristine and chemically treated multi-walled carbon nanotubes (MWCNTs) were employed as solid-phase extraction sorbents for the isolation and enrichment of multi-class pharmaceuticals from the surface water and groundwater, prior to liquid chromatography-tandem mass spectrometry analysis. Thirteen pharmaceuticals that belong to different therapeutical classes (erythromycin, azithromycin, sulfamethoxazole, diazepam, lorazepam, carbamazepine, metoprolol, bisoprolol, enalapril, cilazapril, simvastatin, clopidogrel, diclofenac) and two metabolites of metamizole (4-acetylaminoantipyrine and 4-formylaminoantipyrine) were selected for this study. The influence of chemical treatment on MWCNT surface characteristics and extraction efficiency was studied, and it was shown that HCl treatment of MWCNT leads to a decrease in the amount of surface oxygen groups and at the same time favorably affects the efficiency toward extraction of selected pharmaceuticals. After the optimization of the SPE procedure, the following conditions were chosen: 50 mg of HCl-treated MCWNT as a sorbent, 100 mL of water sample at pH 6, and 15 mL of the methanol-dichloromethane mixture (1:1, v/v) as eluent. Under optimal conditions, high recoveries (79-119%), as well as low detection (0.2 to 103 ng L) and quantitation (0.5-345 ng L) limits, were obtained. The optimized method was applied to the analysis of five surface water and two groundwater samples, and three pharmaceuticals were detected, the antiepileptic drug carbamazepine and two metabolites of antipyretic metamizole.

Solid-phase extraction cartridges with multi-walled carbon nanotubes and effect of the oxygen functionalities on the recovery efficiency of organic micropollutants

“…MWCNTs have been investigated as SPE sorbents for sample preparation of water matrices and to pre-concentrate and extract OMPs such as pesticides (e.g. [11][12][13][14][15][16] ), polycyclic aromatic hydrocarbons 17,18 , industrial compounds 19 , macrolide antibiotics and nonsteroidal anti-inflammatory drugs 20,21 , with recoveries higher than 62%. However, the number of studies dealing with multi-class PSs and CECs with different physicochemical properties are still very limited 20,21 .…”

Development of a multi‐functional concurrent assay using weak cation‐exchange solid‐phase extraction (WCX‐SPE) and reconstitution with a diluted sample aliquot for anti‐doping analysis

“…Moreover, it involves less sample manipulation, which should provide good reproducibility and thus higher sensitivity and selectivity. Various SPE sorbents have also been developed and can be selected according to the target compounds or the sample matrix . Among the various types of SPE, mixed‐mode weak cation‐exchange solid‐phase extraction (WCX‐SPE) offers both cation‐exchange and reversed‐phase interactions, which are properties that facilitate the extraction of various analytes across an extensive range of physicochemical characteristics.…”

“…Various SPE sorbents have also been developed and can be selected according to the target compounds or the sample matrix. 5,[12][13][14][15] Among the various types of SPE, mixed-mode weak cation-exchange solid-phase extraction (WCX-SPE) offers both cation-exchange and reversedphase interactions, which are properties that facilitate the extraction of various analytes across an extensive range of physicochemical characteristics. In the anti-doping field, WADA-prohibited peptides that stimulate the secretion of growth hormones, such as growth hormone releasing peptides (GHRPs), have been successfully analyzed recently, and the analytical method was validated using WCX-SPE.…”

Materials for Solid-Phase Extraction of Organic Compounds

“…The purpose of this is to improve their adsorption properties and extraction efficiency further. Lalovic et al [97] compared the performance of bare MWCNTs and those modified with acidic or basic reagents (i.e., HCl, HNO 3 , and NaOH) for the extraction of multi-class pharmaceuticals from environmental water. It was found that treatment with HCl decreases the content of oxygen groups on the surface and thus reduces the number of electron-acceptor groups, which favors extraction efficiency towards the target compounds.…”