Supramolecular solid-phase extraction of ibuprofen and naproxen from sewage based on the formation of mixed supramolecular aggregates prior to their liquid chromatographic/photometric determination

Determination of residual nonsteroidal anti-inflammatory drugs in aqueous sample using magnetic nanoparticles modified with cetyltrimethylammonium bromide by high performance liquid chromatography

A simple and sensitive solid-phase extraction method for separation and preconcentration of trace amount of four nonsteroidal anti-inflammatory drugs (naproxen, indomethacin, diclofenac, and ibuprofen) using Fe₃O₄ magnetic nanoparticles modified with cetyltrimethylammonium bromide has been developed. For this purpose, the surface of MNP_s was modified with cetyltrimethylammonium bromide (CTAB) as a cationic surfactant. Effects of different parameters influencing the extraction efficiency of drugs including the pH, amount of salt, shaking time, eluent type, the volume of solvent, amount of adsorbent, sample volume, and the time of desorption were investigated and optimized. Methanol has been used as desorption solvent and the extracts were analysed on a reversed-phase octadecyl silica column using 0.02 M phosphate-buffer (pH = 6.02) acetonitrile (65 : 35 v/v) as the mobile phase and the effluents were measured at 202 nm with ultraviolet detector. The relative standard deviation (RSD%) of the method was investigated at three concentrations (25, 50, and 200 ng/mL) and was in the range of 3.98–9.83% (n = 6) for 50 ng/mL. The calibration curves obtained for studied drugs show reasonable linearity (R² > 0.99) and the limit of detection (LOD_s) ranged between 2 and 7 ng/mL. Finally, the proposed method has been effectively employed in extraction and determination of the drugs in biological and environmental samples.

Fabrication of new drug imprinting polymer beads for selective extraction of naproxen in human urine and pharmaceutical samples

A drug imprinting polymer based on suspension polymerization was prepared with N,N-dimethylacrylamide and 1-(N,N-bis-carboxymethyl) amino-3-allylglycerol as functional monomers, N,N methylene diacrylamid as the cross-linker, naproxen as the template and 2,2'-azobis (2-methylbutyronitrile) as the initiator. The drug imprinted polymer was characterized by Fourier transform infrared spectroscopy, elemental analysis, thermogravimetric analysis and transmission electron microscopy. The imprinted polymer of agglomerated micro-particles with multi-pores was used for solid phase extraction. The drug imprinted polymer sorbent was selective for naproxen. The profile of the naproxen uptake by the sorbent reflects good accessibility of the active sites in the imprinted polymer sorbent. In addition, the equilibrium adsorption data of naproxen by imprinted polymer were analyzed by Langmuir isotherm models. The developed method was utilized for determination of naproxen in pharmaceutical and human urine samples by high performance liquid chromatography with satisfactory results.

Surfactant-coated aluminum hydroxide for the rapid removal and biodegradation of hydrophobic organic pollutants in water

The removal of hydrophobic organic pollutants in water to surfactant-coated aluminum hydroxide [surfactant-Al(OH)(3)] was investigated. Anionic surfactants such as sodium dodecyl sulfate (SDS), sodium bis(2-ethylhexyl)sulfosuccinate (AOT), and sodium oleate were sorbed on positively charged aluminum hydroxide at pH 7 and formed hydrophobic aggregates that can incorporate hydrophobic organic pollutants in water. Because of the hydrophobic interaction and decrease in the positive charge, surfactant-Al(OH)(3) was coagulated into precipitates that can readily be separated from water. Hydrophobic organic pollutants such as alkylphenols, polycyclic aromatic hydrocarbons, estrogens, chlorinated antifungals, and pesticides were well collected to the precipitates and thus efficiently removed from water. The collection of hydrophobic organic pollutants was correlated to their aqueous-octanol distribution coefficient. The decomposition of hydrophobic organic pollutants was examined using a bacterial agent (Bacillus subtilis). Hydrophobic organic compounds collected to AOT-Al(OH)(3) or sodium oleate-Al(OH)(3) were insufficiently decomposed. On the other hand, nonylphenol, octylphenol, and pendimethalin collected to SDS-Al(OH)(3) were decomposed within 1 week. The decomposition was accelerated by the collection to SDS-Al(OH)(3).

Analysis of sulfonamides in environmental water samples based on magnetic mixed hemimicelles solid-phase extraction coupled with HPLC-UV detection

The magnetic mixed hemimicelles solid-phase extraction (MMHSPE), based on the adsorption of cation surfactant octadecyltrimethylammonium bromide (OTMABr) onto magnetite nanoparticles (Fe(3)O(4) NPs) to form mixed hemimicelles, was proposed for the preconcentration of several sulfonamides (SAs) compounds including sulfamethoxazole (SMX), sulfamethoxydiazine (SMD), sulfadimethoxine (SDM) and sulfaquinoxaline (SQX) from environmental water samples. This method avoided the time-consuming column-passing process of loading large volume samples in traditional SPE through the rapid isolation of OTMABr-coated Fe(3)O(4) NPs with an adscititious magnet. Mixed hemimicelles formed on the surface of Fe(3)O(4) NPs by OTMABr showed great adsorptive tendency towards analytes. The OTMABr-coated Fe(3)O(4) NPs adsorbents were easy to be prepared, low cost and environmentally friendly. A comprehensive study on the adsorption conditions such as the amount of the surfactant, the solution pH, the desorption condition and the maximum extraction sample volume were optimized. A concentration factor of 1000 was achieved by the extraction of 500 mL of environmental water samples using MMHSPE. Detection limits obtained for SMX, SMD, SDM and SQX were 0.026, 0.024, 0.033 and 0.030 microg L(-1), respectively. Good recoveries (70-102%) with low relative standard deviations (1-6%) were achieved in analyzing spiked water samples. Low concentration of SQX was found in hospital primary and final sewage effluent sample.

JEM spotlight: recent advances in analysis of pharmaceuticals in the aquatic environment

Both ecosystem and human health rely on clean, abundant supplies of water, thus many classes of potential pollutants are regulated. In recent years, the possible risks associated with largely uncontrolled inputs of pharmaceuticals to rivers, lakes, groundwater, and coastal waters, mainly via wastewater, have been a focus of much research. During this time, our capacity to sequester, identify, and quantify pharmaceuticals in environmental matrices has improved. Devices have emerged to allow passive uptake of drugs to augment or replace laborious grab sampling. Advances in sample preparation have streamlined extraction procedures and removed interfering matrix components. New instrumental techniques have allowed faster, more accurate and sensitive detection of drugs in water samples. This review highlights all of these advances, from sample collection to instrumental analysis, which will continue to help us better understand the fate and effects of pharmaceuticals in aquatic systems.