Nanofluid of magnetic‐activated charcoal and hydrophobic deep eutectic solvent: Application in dispersive magnetic solid‐phase extraction for the determination and preconcentration of warfarin in biological samples by high‐performance liquid chromatography

Abstract

In this study, for the first time, nanofluid of magnetic-activated charcoal and hydrophobic deep eutectic solvent (AC@Fe 3 O 4 -DES) based dispersive magnetic solid-phase extraction was successfully applied for the determination and preconcentration of warfarin in plasma and urine samples. The hydrophobic DES was prepared by mixing tetramethylammonium chloride (as hydrogen bond acceptor) and thymol (as hydrogen bond donor) and acted simultaneously as both carrier and stabilizer for magnetic nanoparticles. In this method, the nanofluid as a new extraction solvent was rapidly injected into the aqueous sample, which led to improvement of the mass transfer of the analytes into the sorbent and reduction of the extraction time. In the screening step, the fractional factorial design was applied for selecting some important parameters which significantly affected the extraction procedure.The effective parameters were then optimized by Box-Behnken design. Under the optimal conditions, the limits of detection were in the range of 0.3-1.6 ng/ml. A good linear range was observed in the range of 1.0-500.0 ng/ml for water and 5.0-500.0 ng/ml for urine and plasma. The intra-and inter-day relative standard deviations were 2.7-3.2 and 1.9-4.5% for five replications, respectively. Based on the results, the proposed method was successfully applied for the determination of warfarin in biological samples, using high-performance liquid chromatography.

Copper nanoparticles supported on magnetic functionalized chicken feather‐derived activated carbon/metal–organic frameworks nanocomposite: As an efficient adsorbent for the removal of methylene blue and a unique heterogeneous catalyst for the synthesis of tetrahydrobenzo[b]pyran derivatives

“…43 The as-synthesized Fe 3 O 4 @CFC-COOH exhibit diffraction peaks at 2θ values 63.17, 57.32, 43.57, 35.97, and 30.92 , which is related to the Fe 3 O 4 nanoparticles. 40 For pristine TMU-16, the diffraction peaks were in good agreement with those previously reported for TMU-16 crystals. 44 The sharp and narrowed peaks of the Fe 3 O 4 @CFC-COOH@TMU-16 composite are similar to the pattern of pure TMU-16 and indicate the high-quality crystalline products.…”

“…The CFC pattern displays a broad peak at about 2θ = 24°, which confirms the carbon's amorphous nature and was consistent with the reported literature 43 . The as‐synthesized Fe 3 O 4 @CFC‐COOH exhibit diffraction peaks at 2θ values 63.17, 57.32, 43.57, 35.97, and 30.92°, which is related to the Fe 3 O 4 nanoparticles 40 . For pristine TMU‐16, the diffraction peaks were in good agreement with those previously reported for TMU‐16 crystals 44 .…”

“…FTIR spectra were obtained at each stage of Fe 3 O 4 @CFC‐COOH@TMU‐16@Cu synthesis and are shown in Figure 1. The FTIR spectrum of the activated carbon of CFC is similar to the patterns reported in the references 40 . As shown in the FTIR spectra of compound CFC‐COOH, functional groups containing abundant oxygen (C=O, O‐H, and C‐O) appeared after the functionalization of CFC with the carboxyl group.…”

“…41 The peak in the area of 630.28 cm À1 is related to the Fe 3 O 4 nanoparticles, which appeared in the corresponding spectrum after the magnetization of the functionalized activated carbon. 40 There is no obvious difference between the FTIR spectra of pure TMU-16 and the nanocomposite, which indicates that the presence of Fe 3 O 4 @CFC-COOH does not limit the growth of the MOF, and the networks of TMU-16 were well S C H E M E 1 Schematic representation of the production of Fe 3 O 4 @CFC-COOH@TMU-16@Cu. synthesized at the surface.…”

“…The FTIR spectrum of the activated carbon of CFC is similar to the patterns reported in the references. 40 As shown in the FTIR spectra of compound CFC-COOH, functional groups containing abundant oxygen (C=O, O-H, and C-O) appeared after the functionalization of CFC with the carboxyl group. The highintensity peak located at 1700 cm À1 is related to the C=O group.…”