Dispersive Micro-solid Phase Extraction Research Articles

A hybrid imprinted polymer based on magnetic graphene oxide and carbon dots for ultrasonic assisted dispersive solid-phase microextraction of oxycodone

To promote the development of molecular imprinting technique in the separation and analysis of oxycodone, molecularly imprinted polymer based on the magnetic graphene oxide and carbon dots nanoparticles (MIP@MGO/CDs NPs) was developed using ultrasonic-assisted dispersive solid-phase microextraction (UA-DSPME) and high performance liquid chromatography (HPLC). The morphology and structure characterization of synthesized nanoparticles are assessed by scanning electron microscope (SEM), Brunauer-Emmett-Teller analysis (BET), Fourier transform infrared spectroscopy (FTIR), vibrating sample magnetometer (VSM) and thermogravimetric analysis (TGA). The adsorption isotherms of MIPs followed the Langmuir model with the maximum adsorption capacity of 99 mg/g and imprinting factor of 3.39. Under optimized conditions, which achieved by central composite design under response surface methodology, the detection limit (S/N = 3) was obtained 0.80 ng/mL in the linear range of 1–2000 ng/mL. The average recoveries of oxycodone were calculated from 92.50 to 103.20% in human urine samples with RSD less than 3.65%.

Molecularly imprinted dispersive solid-phase microextraction sorbents for direct and selective drug capture from the undiluted bovine serum

The preparation of well-defined new hydrophilic molecularly imprinted polymer (MIP) microspheres and their use as the dispersive solid-phase microextraction (dSPME) sorbents for direct and selective drug (i.e., propranolol) capture from the undiluted bovine serum are described. These MIPs have surface-grafted dense poly(2-hydroxyethyl methacrylate) (PHEMA) brushes with different molecular weights and grafting densities. They were readily prepared via the facile reversible addition-fragmentation chain transfer (RAFT) coupling chemistry. Both the molecular weights and grafting densities of PHEMA brushes showed significant influence on their complex biological sample-compatibility, and only those MIPs bearing PHEMA brushes with high enough molecular weights and grafting densities could selectively recognize propranolol in the undiluted pure milk and bovine serum. In particular, they have proven to be highly versatile dSPME sorbents for directly and selectively capturing propranolol from the undiluted bovine serum with satisfactory recoveries (85.2–97.4%) and high accuracy (RSD = 2.3–3.7%), even in the presence of one analogue of propranolol. The limit of detection was 0.002 μM with a linear correlation coefficient of 0.9994 in the range of 0.01–100 μM. Excellent precision was verified by both the intraday and interday analytical results. Their good reusability was also confirmed. This work demonstrates the high potential of such hydrophilic MIP-based dSPME sorbents for rapid, accurate, and reliable drug determination in complex biological samples.

Development of a Stirring-Dependent Magnetic Dispersive Solid Phase Extraction Method Coupled with Ferrofluid-Based Dispersive Liquid–Liquid Microextraction for the Extraction of Some Pyrethroid Pesticides from Fruit Juices

In the present work, a new and efficient sample treatment method based on the combination of stirring-dependent magnetic dispersive solid phase microextraction and ferrofluid-based dispersive liquid–liquid microextraction has been developed for the extraction of some pyrethroid pesticides (bifenthrin, phenothrin, tetramethrin, cyhalothrin, permethrin, and cypermethrin) from fruit juices prior to their determination with gas chromatography–mass spectrometry. For this purpose, a few milligrams of a synthesized magnetic sorbent (Fe3O4@polythiophene) is added into a sample solution containing the analytes and stirred at high rate. By this action, particles of the magnetic sorbent are detached from the magnetic stir bar surface and completely dispersed throughout the solution. After stopping stirring, the particles containing the adsorbed analytes are rapidly returned onto the stir bar. Then, the stir bar is taken and eluted with an appropriate solvent to desorb the analytes. Afterward, the eluent is mixed with a few microliters of a synthesized ferrofluid and the mixture is rapidly injected into deionized water placed in a conical glass test tube for more enrichment of the analytes. In the next step, the ferrofluid settled down at the bottom of the tube in the presence of an external magnet and the supernatant is discarded. After back-extraction of the analytes with n-hexane, an aliquot of the extract is injected into the determination system. Under optimal conditions, the developed method offered high enrichment factors (1380–1660) and extraction recoveries (69–83%), and low limits of detection (4.0–12 ng L−1) and quantification (14–40 ng L−1). The relative standard deviations were ≤ 7.1% for intra-day (n = 6) and inter-day (n = 4) precisions at a concentration of 250 ng L−1 of each analyte. Finally, six different fruit juice samples were successfully analyzed by the introduced method and cypermethrin was detected in apple juice at a concentration of 110 ± 0.5 ng L−1.

Switchable-hydrophilicity solvent liquid–liquid microextraction prior to magnetic nanoparticle-based dispersive solid-phase microextraction for spectrophotometric determination of erythrosine in food and other samples

A combination of switchable-hydrophilicity liquid–liquid microextraction prior to magnetic nanoparticle-based dispersive solid-phase microextraction is proposed for the determination of erythrosine using UV/Vis spectrophotometry at 520 nm. Under optimum conditions (i.e., 1.0 mL octylamine as the extraction solvent, 1.5 mL of 10.0 M sodium hydroxide as the phase separation trigger, pH 4.0, 750 µL of acetone as the eluent, 10.0 mg of Fe3O4@XAD-16 as the adsorbent, and 15.0 mL of the sample solution), the method showed a superior analytical performance with limits of detection less than 25.9 ng mL−1, limits of quantitation less than 86.3 ng mL−1 and linear dynamic ranges ranging between 86.3 and 1000 ng mL−1. Percentage relative standard deviations were less than 4.1 and 7.2% for intra-day and inter-day, respectively. The method was successfully applied for the extraction and determination of erythrosine in food samples and other consumer products with recoveries in the range of 94.6–103.9% and within extraction time of 7.8 min per sample.

Simultaneous extraction and preconcentration of three beta (β)-blockers in biological samples with an efficient magnetic dispersive micro-solid phase extraction procedure employing in situ sorbent modification

A straightforward and sensitive magnetic dispersive micro-solid phase extraction based on in situ sorbent modification in sample solution was developed for the simultaneous extraction of metoprolol, atenolol, and propranolol (three beta-blockers) in human plasma and urine samples. To prepare a suitable sorbent, magnetic graphene oxide as a magnetic core was synthesized and modified with sodium dodecyl sulfate in the sample solution containing the analytes. In the procedure, the sorbent synthesis and the analyte extraction were simultaneously performed in the sample solution, which leads to a reduction in the time and cost of the determination of the analytes. Three surfactants such as cetyltrimethylammonium bromide, triton X100, and sodium dodecyl sulfate were utilized to modify the magnetic graphene oxide composites and their effects on the extraction of beta-blockers were investigated. The effective variables in the microextraction process of the analytes were optimized based on a design of experiment strategy. Under the optimal conditions, the dynamic ranges of linear were 5–10000, 50–5000, and 10–5000 ng mL–1 with method detection limits of 0.8, 10, and 2 ng mL– 1 for Atenolol, Metoprolol, and Propranolol, respectively The relative standard deviations of the intra-day and inter-day were less than 2.96% and 5.35% (n = 5) for the determination of the analytes, respectively. A suitable enrichment factors of 14, 16, and 18 were obtained for the determination of metoprolol, atenolol, and propranolol, respectively. Finally, the suggested method was successfully applied to measure the beta-blockers in several plasma and urine samples of healthy volunteers without taking drugs and patient volunteers with taking drugs. The method shows suitable relative recoveries in the ranges of 82.4–109.4% and 77.6–95.9% for the analysis of urine and plasma samples with relative standard deviations between 3.1 and 6.7% for the determination of all analytes, respectively.

Molecularly Imprinted Polymer for a Smart Dispersive Micro-Solid Phase Extraction Technique for Assessing Trace Level Aflatoxins in Cultured Fish.

Molecularly imprinted technology (MIT) consists of preparing materials exhibiting specific recognition cavities to selective mimic the target analytes. The prepared materials promote selective interactions with the targets and avoid interactions of concomitants from complex food, biological, clinical, and environmental matrices. This chapter provides information on a recent development of a vortex-assisted micro-solid phase extraction using a molecularly imprinted polymer (MIP) as an adsorbent for aflatoxins (AFs) determination in cultured fish. MIP particles were synthesized by precipitation polymerization using 5,7-dimethoxycoumarin as a dummy template, methacrylic acid as a functional monomer, divinylbenzene as a cross-linker, and 2,2-azobisisobutyronitrile as an initiator. Polymerization following the precipitation method guarantees homogeneous particle size distribution and the integrity of the imprinted cavities. The MIP microparticles were found to have 5μm in diameter and a spherical shape. Important parameters such as sample extract pH, adsorption stirring speed and time, desorption stirring speed and time, elution solvent composition and volume, and polymer mass, were fully optimized. The pre-concentration method allows therefore the assessment of four major AFs (B1, B2, G1, and G2) present in cultured fish at very low levels, with pre-concentration factors from 15 to 50 depending of the volume of extract used for performing the dispersive micro-solid phase extraction (D-μ-SPE).

In situ adsorbent formation based dispersive micro-solid phase extraction using a deep eutectic solvent as an elution solvent for the extraction of some pesticides from honey samples prior to GC-MS analysis

In this work, a simple, inexpensive, green, and fast dispersive micro-solid phase extraction method has been developed for the extraction of several pesticides from honey samples. In this approach, a solution of curcumin was prepared in ethanol and it was dispersed into a sample solution with the aid of a syringe. Curcumin was precipitated in the sample solution as tiny particles and the analytes were adsorbed onto them. After centrifugation the adsorbed analytes were eluted with tetrabutylammonium chloride:dichloroacetic acid deep eutectic solvent. The dissolved analytes in the deep eutectic solvent were analyzed by gas chromatography-mass spectrometry. Parameters affecting the extraction efficiency of the method including sorbent amount, dispersive solvent type and volume, elution solvent type and volume, salting out effect, and sonication time were investigated. Extraction recovery of the method was obtained in the range of 70-83%. Also wide calibration ranges and low detection limits (0.22-0.81 ng g-1) were obtained. Relative standard deviation values for intra- and inter-day precisions were ≤10.2% for all analytes at a concentration of 5 ng g-1 of each (n = 6). Finally, ten honey samples were analyzed and data showed that all of the studied samples were free of the analytes.

Nano-bismuth sulfide based dispersive micro-solid phase extraction combined with energy dispersive X-ray fluorescence spectrometry for determination of mercury ions in waters

Nano-Bi2S3 as a solid sorbent for ultra-sound assisted dispersive micro-solid phase extraction of Hg(ii) ions from surface and sea waters prior to EDXRF determination.

Reduced Graphene Oxide-Cadmium Sulfide Quantum Dots Nanocomposite Based Dispersive Solid Phase Microextraction for Ultra-Trace Determination of Carbamazepine and Phenobarbital

This research presents a fast, sensitive, and selective ultrasound-assisted dispersive solid phase microextraction technique for simultaneous preconcentration and determination of ultra-trace amount of carbamazepine and phenobarbital. Reduced graphene oxide sheets decorated with cadmium sulfide quantum dots was synthesized, characterized, and used as a high capacity adsorbent. A high performance liquid chromatography with UV detector (HPLC-UV) instrument with 58:42 composition of methanol:acetic acid/acetate buffer (pH = 5; 0.05 mol L-1) as the mobile phase and set on the wavelength of 230 nm was used to separate and quantify the analytes. In this regard, different parameters affecting adsorption and desorption of the analytes on the surface of the nanocomposite were studied and optimized to maximize the efficiency of the method. The method was linear in the ranges of 0.5-180 and 0.5-140 ng mL−1 (correlation coefficient (r) > 0.999) with limits of detection of 0.19 and 0.24 ng mL−1 for carbamazepine and phenobarbital, respectively. Eventually, to evaluate the efficiency of the proposed method for the determination of pharmaceuticals in biological samples, different real samples including breast milk, urine and human plasma were tested. Obtained recoveries values were within the range of 96.3 ± 2 to 103.7 ± 3.3% which showed satisfactory efficiency.

Correction: Nano-bismuth sulfide based dispersive micro-solid phase extraction combined with energy dispersive X-ray fluorescence spectrometry for determination of mercury ions in waters

Correction for ‘Nano-bismuth sulfide based dispersive micro-solid phase extraction combined with energy dispersive X-ray fluorescence spectrometry for determination of mercury ions in waters’ by Katarzyna Pytlakowska et al., J. Anal. At. Spectrom., 2021, 36, 786–795, DOI: 10.1039/D0JA00477D.

Covalent organic framework-LZU1@PEI@Fe3O4-based magnetic dispersive micro-solid phase extraction of tetracyclines from environmental water prior to HPLC analysis.

In this work, COF-LZU1@PEI@Fe3O4 was synthesized by immobilization of COF-LZU1 onto the surface of polyethyleneimine-functionalized Fe3O4 nanoparticles (PEI@Fe3O4) and employed as an adsorbent for magnetic dispersive micro-solid phase extraction of tetracyclines (TCs). COF-LZU1@PEI@Fe3O4 was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction and nitrogen adsorption-desorption isotherms analysis. The optimal extraction and desorption conditions were as follows: 15.00 mL sample solution (pH 7.0) extracted with 5.0 mg of adsorbent for 30 min at 30 °C, and then desorbed with 1.50 mL methanol/acetonitrile/0.02 mol L-1 oxalic acid solution (v/v, 1 : 2 : 7). Good linearities were obtained between the peak area and TC concentration ranging from 5-500 μg L-1 with correlation coefficients (R2) higher than 0.9992 and limits of detection lower than 0.51 μg L-1. The relative standard deviations (RSDs) of intra-day and inter-day were less than 5.7% and 7.4%, respectively. The developed method was successfully applied to the determination of TCs in environmental water samples with recoveries in the range of 87.0-113.8% and RSDs less than 5.1%, suggesting great potential of COF-LZU1@PEI@Fe3O4 for efficient extraction and analysis of trace TCs in water samples.

Water Cleaning Dispersive Solid Phase Microextraction and UHPLC-DAD Determination of 16 PAHs in Some Fertilizer Samples

Water Cleaning Dispersive Solid Phase Microextraction and UHPLC-DAD Determination of 16 PAHs in Some Fertilizer Samples

Application of magnetic carbon nano-onions in dispersive solid-phase extraction combined with DLLME for extraction of pesticide residues from water and vegetable samples

A dispersive solid-phase microextraction method based on magnetic carbon nano-onions (MCNOs) was developed for the extraction and preconcentration of some pesticides from water and vegetable samples. For more cleanup and preconcentration, a dispersive liquid-liquid microextraction (DLLME) method was employed after performing the first step. In this method, firstly, MCNOs were prepared and then used for adsorption of the analytes from the sample solution. After that, the adsorbed analytes were eluted with an appropriate water-miscible organic solvent and used as a dispersive solvent in the following DLLME procedure. The extracted analytes were quantified by gas chromatography-mass spectrometry (GC-MS) in selected ion monitoring (SIM) mode. Various factors affecting the method efficiency such as sorbent weight, salt effect, pH, temperature, and type and volume of eluent and extraction solvent were optimized. This method showed wide linear ranges with a coefficient of determination ≥ 0.994, and low limits of detection (0.001-0.005 ng mL-1) and quantification (0.003-0.019 ng mL-1) under optimal conditions. Also, a good precision (relative standard deviation ≤ 8.6%) for five replicates and a satisfactory accuracy (mean relative recoveries between 82 and 99%) were obtained. It can be considered as an efficient and environment friendly method for the extraction of analytes from vegetable and fruit juices and water samples.

Optimized preconcentration method using magnetic dispersive solid-phase microextraction with GO–γFe2O3nanoparticles for the determination of Se in fish samples by FIA-HG-AAS

Magnetic nanoparticles of GO–γ-Fe2O3were applied for the preconcentration of Se in fish samples and determination by hydride generation atomic absorption spectrometry and flow injection analysis.

Dispersive solid phase extraction using graphitic carbon nitride microparticles for the determination of trace amounts of lead in water samples

In this work, ultrasound-assisted dispersive micro-solid phase extraction (USA-D-µSPE) technique using graphitized carbon nitride (g-C3N4) is proposed for the preconcentration of low level of lead in aqueous samples. In this method, microparticles of graphitized carbon nitride sorbent were dispersed in the samples using ultrasonic bath and Pb(II) ions were directly adsorbed on the surface of g-C3N4 particles. After adsorption and desorption of lead ions from g-C3N4 particles, the Pb concentration was determined by the inductively coupled plasma- optical emission spectroscopy (ICP-OES). The main advantages of this method are high speed, simplicity and cheapness. The effects of pH, sorbent amount, eluent type and time on the recovery of the analyte were investigated. Under the optimized conditions and preconcentration of 10 mL of sample, the detection limit of 1.24 μg L-1 was obtained. The results were validated by standard reference materials (NIST, SRM) and spiking of real samples by USA-D-µSPE procedure.

Customized dispersive micro-solid-phase extraction device combined with micro-desorption for the simultaneous determination of 39 multiclass pesticides in environmental water samples

A dispersive micro-solid phase extraction (d-µ-SPE) procedure was developed for the simultaneous extraction of 39 multiclass pesticides, containing a variety of chemical groups (organophosphate, organochlorine, pyrethroid, strobilurin, thiocarbamate, triazole, imidazole, and triazine), from water samples. A customized d-µ-SPE glass device was combined with a multi-tube platform vortex and a micro-desorption unit (Whatman Mini-UniPrep G2 syringeless filter), which allowed the unique simultaneous desorption, extract filtration, and injection. A simplex-centroid mixture design and Doehlert design were employed to optimize the extraction conditions. The optimized extraction conditions consisted of an extraction time of 30 min, an addition of 6.74 % of NaCl into 100 mL of water sample, and a desorption time of 24 min with 500 µL of EtAc. The procedure provided a low limit of detection (LOD), ranging from 0.51 ng L−1 (4,4-DDE) to 22.4 ng L−1 (dimethoate), and an enrichment factor ranging from 72.5 (dimethoate) to 200 (tebuconazole). The relative recoveries of the pesticides from spiked freshwater and seawater ranged from 74.2 % (endrin) to 123 % (molinate). The proposed procedure was applied to detect the presence of multiclass pesticides in environmental water samples. Three pesticides commonly applied in Brazil, namely, malathion, dimethoate, and lambda-cyhalothrin, were detected in concentrations ranging from <LOD to 120 ng L−1 (dimethoate).

Deep eutectic solvent containing 2-(3-hydroxy-1-methylbut-2-enylideneamino)pyridine-3-ol immobilized on magnetic graphene oxide as a selective sorbent for dispersive micro-solid phase extraction of cadmium ions

A sorbent with high selectivity and capacity for cadmium ions was prepared through immobilization of deep eutectic solvent (DES) of ChCl- glycerol containing the ligand 2-(3-hydroxy-1-methylbut-2-enylideneamino)pyridine-3-ol (acacapyrH2) on the magnetic graphene oxide. A dispersive micro-solid phase extraction was designed, and the separated/preconcentrated cadmium ion was determined by flow injection flame atomic absorption spectrometry. After the optimization of effective parameters, the method showed linearity in the concentration range of 0.25–15 µg L−1 with the coefficient of determination (r2) of 0.9991 and enhancement factor of 195 for cadmium. The method was very sensitive with the detection limit (defined as 3Sb/m) of 0.06 µg L−1. The method was successfully applied to the determination of Cd(II) in water (drinking and river), fruit (lemon, apricot, and peach) and meat (fish, chicken, and cow meat) samples.

Development of a New Magnetic Dispersive Solid-Phase Microextraction Coupled with GC-MS for the Determination of Five Organophosphorus Pesticides from Vegetable Samples

A magnetic dispersive solid-phase microextraction procedure (MDμ-SPE) was developed to extract organophosphorus pesticides (OPP), including ethion, chlorpyrifos, diazinon, malathion, and fenitrothion, from vegetable samples before their analysis with gas chromatography/mass spectroscopy (GC/MS). Magnetic graphene@Fe3O4@SiO2@TiO2 nanocomposites were synthesized as a unique sorbent using the sol-gel and co-precipitation procedures. The ability of the prepared sorbent to extract the analytes was compared with several other sorbents. Effective factors in the MDμ-SPE method were thoroughly optimized by one factor at a time and the experimental design approach. Under the optimum condition of the OPP determination, the calibration curves were linear over a wide range of analyte concentrations with the correlation coefficient (R2) between 0.995 and 0.9986. Besides, the method showed high preconcentration factors (PF ≥ 217) and suitable relative standard deviations (RSD ≤ 4.73). Limit of detections (LODs) and limit of quantitations (LOQs) were in the range of 0.06-1.49 and 0.2-4.96 ng mL−1 for water sample analysis, respectively. Application of the method for the determination of the analytes in real samples such as tomato and lettuce samples indicated the method is proper for the OPP measurement in the vegetable samples with a recovery percentage between 93.89 and 106.67% and a relative standard deviation of less than 5.77%. The procedure for the residue determination of organophosphorus pesticides has various advantages such as no need for centrifugation step to the sorbent separation, low sorbent and sample solution consumption, high sensitivity, and low analysis time.

Dispersive micro-solid phase extraction combined with switchable hydrophilicity solvent-based homogeneous liquid-liquid microextraction for enrichment of non‐steroidal anti‐inflammatory drugs in environmental water samples

Herein, a sensitive and green method combining dispersive micro-solid phase extraction (D-μ-SPE) and homogeneous liquid-liquid microextraction (HLLME) has been developed. Magnetic layered double hydroxide nanoparticals were prepared and used as adsorbents in d-μ-SPE. The fascinating dissolvable characteristic of the material can eliminate elution step without usage of toxic organic solvents. Dipropylamine was used as a pH-triggered switchable hydrophilicity solvent that can change the miscible/immiscible states reversibly, achieving fast two-phase separation. To demonstrate the applicability of proposed method, three non-steroidal anti-inflammatory drugs including ketoprofen, naproxen and tolmetin in water samples were enriched and purified prior to HPLC-UV analysis. The influencing parameters such as pH of sample solution, amount of sorbent, vortex time, type and volume of acidic solution and SHS, volume of NaOH were optimized in detail. The method exhibits good linearity (0.1–50 ng/mL), low limits of detection (0.02–0.05 ng/mL), high precision (RSDs<9.3%) and acceptable accuracy (97.2%-105.7%). Therefore, the presented procedure is fast, sensitive, simple and suitable for determination of non-steroidal anti-inflammatory drugs from aqueous matrices.

Sono-synthesized Fe3O4–GO–NH2 nanocomposite for highly efficient ultrasound-assisted magnetic dispersive solid-phase microextraction of hazardous dye Congo red from water samples

This research focuses on the preparation of amino-functionalized magnetic graphene oxide nanocomposite (Fe3O4–GO–NH2), which increases the pre-concentration efficiency of Congo red residue in water samples. Their characterizations by FT-IR, SEM, EDX, and VSM were carried out in line with the magnetic property. The magnetic adsorbent was mainly used for the pre-concentration of anionic dye under optimized conditions of ultrasound-assisted magnetic dispersive solid-phase microextraction (UA-MDSPME). Typically, pre-concentration optimization conditions such as the pH of the solution, sorbent amount, power and sonication time, type of eluting solvent and its concentration were precisely investigated before the determination by UV–visible spectrophotometry. The analytical performance of the UA-MDSPE method was validated and found to have a linear range of 1.0–25.0 mg L−1 with R2 > 0.999. The limits of detection and quantification were 4.3 µg L−1 and 14.4 µg L−1, respectively. The precision of the method calculated from the slope of the calibration curve (%RSD, n = 3 × 3) for intra-day and inter-day analyses was 3.23 and 4.74, respectively. The extraction of Congo red dye from real water samples (drinking water, swamp water, and tap water) ranged from 90.65 to 105.8%. The enrichment factor of the developed procedure was averaged to 32.4 folds, ensuring the determination of trace amounts of residual dye in the water samples. It is, therefore, concluded that the magnetic adsorbent is an efficient method for the pre-concentration of hazardous dye from aqueous solution.