Grafting of allylimidazole and n-vinylcaprolactam as a thermosensitive polymer onto magnetic nano-particles for the extraction and determination of celecoxib in biological samples

Innovative Solid-Phase Extraction Strategies for Improving the Advanced Chromatographic Determination of Drugs in Challenging Biological Samples

In the past few decades, considerable scientific strides have been made in the subject of drug analysis in human biological samples. However, the risk caused by incorrect drug plasma levels in patients still remains an important concern. This review paper attempts to investigate the advances made over the last ten years in common sample preparation techniques (SPT) for biological samples based on solid sorbents, including solid-phase extraction (SPE) and solid-phase micro-extraction (SPME), and in particular in the field of molecularly imprinted polymers (MIPs), including non-stimuli-responsive and stimuli-responsive adsorbents. This class of materials is known as 'smart adsorbents', exhibiting tailored responses to various stimuli such as magnetic fields, pH, temperature, and light. Details are provided on how these advanced SPT are changing the landscape of modern drug analysis in their coupling with liquid chromatography-mass spectrometry (LC-MS) analytical techniques, a general term that includes high-performance liquid chromatography (HPLC) and ultra-high performance liquid chromatography (UHPLC), as well as any variation of MS, such as tandem (MS/MS), multiple-stage (MSn), and high-resolution (HRMS) mass spectrometry. Some notes are also provided on coupling with less-performing techniques, such as high-performance liquid chromatography with ultraviolet (HPLC-UV) and diode array detection (HPLC-DAD) detection. Finally, we provide a general review of the difficulties and benefits of the proposed approaches and the future prospects of this research area.

Determination of parabens in breast milk using stir bar sorptive extraction coupled with UHPLC-UV

We developed an analytical method based on ultra-high performance liquid chromatography with UV detection, using a stir bar coated with amino/hydroxyl bifunctional microporous organic network (B-MON), for the analysis of parabens in breast milk samples. B-MON demonstrated superior performance with maximal methylparaben adsorption of 112.15 mg/g. Kinetic fitting revealed that outer diffusion was the key limiting step, and the adsorption was chemisorption. The thermodynamic analysis demonstrated that increased methylparaben adsorption was found at higher temperatures in spontaneous processes. The developed approach showed excellent linearity (R2 ≥ 0.9964) and a low detection limit (0.01 μg/L). Recoveries ranged from 85.8 to 105.5 % and the relative standard deviation was lower than 9.2 %. Based on the daily exposure assessment, these pollutants do not pose unacceptable health hazards to babies. However, the high detection frequencies (41.9%-93.5 %) suggest that breast milk still should be monitored.

A nano curcumin-multi-walled carbon nanotube composite as a fluorescence chemosensor for trace determination of celecoxib in serum samples

A novel method is presented here for trace determination of celecoxib by fluorescence detection using curcumin nanoparticles (CurNPs) loaded on multi-walled carbon nanotubes with carboxyl functional groups (CurNPs-MWCNT-COOH). For the synthesis of CurNPs-MWCNT-COOH, CurNPs were retained on carbon nanotubes with the aid of ultrasound waves. The sensing method is based on monitoring the quenching of synthesized CurNPs-MWCNT-COOH fluorescence by celecoxib. The morphology of CurNPs-MWCNT-COOH was studied by transmission electron microscopy (TEM) of the composite alone and in the presence of celecoxib. The effects of several parameters on the production of CurNPs-MWCNT-COOH and determination of celecoxib such as the Triton X-100 concentration, the amount of MWCNT-COOH and the pH were evaluated and optimum conditions were established. The calibration graph was found to be linear in the range of 20-220 ng mL^-1 for celecoxib in the initial solution. The detection limit based on three times the standard deviation of the blank was 5.8 ng mL^-1 for celecoxib and relative standard deviations (RSD) of 3.6% and 1.8% were obtained for eight replicate determinations of 60 ng mL^-1 and 180 ng mL^-1 of celecoxib, respectively. The method was applied to the determination of celecoxib in serum samples.

Application of core-satellite polydopamine-coated Fe3O4 nanoparticles-hollow porous molecularly imprinted polymer combined with HPLC-MS/MS for the quantification of macrolide antibiotics

Core-satellite-structured magnetic nanosorbents (MNs) used for the selective extraction of macrolide antibiotics (MACs) were prepared in this study. The MNs (core-satellite polydopamine-coated Fe₃O₄ nanoparticles-hollow porous molecularly imprinted polymer) consisted of polydopamine-coated Fe₃O₄ nanoparticles (Fe₃O₄@PDA) "core" linked to numerous hollow porous molecularly imprinted polymer (HPMIP) "satellites" with bridging amine functional groups. It is worth mentioning that HPMIPs act as "anchors" for selectively capturing target molecules. Polymers were characterized using TEM, SEM, FT-IR, VSM, and TGA and applied as magnetic dispersive solid-phase extraction (MDSPE) sorbents for the enrichment of trace MACs from a complex food matrix prior to quantification by HPLC-MS/MS. Nanocomposites revealed outstanding magnetic properties (36.1 emu g^-1), a high adsorption capacity (103.6 μmol g^-1), selectivity (IF = 3.2), and fast kinetic binding (20 min) for MACs. The multiple advantages of the novel core-satellite-structured magnetic molecularly imprinted nanosorbents were confirmed, which makes us believe that the preparation method of the core-satellite MNs can be applied to other fields involving molecular imprinting technology.

The synthesis, characterization and applications of poly[N-isopropylacrylamide-co-3-allyloxy-1,2-propanediol] grafted onto modified magnetic nanoparticles

In this paper, a novel method is investigated for the extraction, determination, and delivery of ceftazidime in simulated gastric and real biological fluids such as serum plasma and urine in in vitro drug delivery systems.

A pH-responsive and magnetic Fe3O4@silica@MIL-100(Fe)/β-CD nanocomposite as a drug nanocarrier: loading and release study of cephalexin

In the present work, a novel magnetic and pH-responsive porous nanocomposite was prepared by the surface grafting of β-cyclodextrin onto Fe₃O₄@silica@MIL-100(Fe).