Dispersive Micro-solid Phase Extraction Research Articles

Vortex-assisted dispersive micro-solid phase extraction based on nanostructured imprinted polymer: A comparison study between spectrophotometric and solution scanometric techniques

In the present work, methyl red molecularly imprinted polymeric (MR-MIP) nanostructure was synthesized using the precipitation polymerizations for the separation of MR dye from aqueous media. The as-prepared MIP was characterized using colorimetry, infrared (IR) spectroscopy, and scanning electron microscopy (SEM). In addition, vortex-assisted dispersive micro-solid phase extraction (VAD-µSPE) based on MIP nanostructure was accomplished as a simple and efficient method for selective preconcentration of low amounts of MR from aqueous solutions. The effects of important parameters such as pH, adsorbent dose, eluent volume, and vortex adsorption–desorption time on the extraction efficiency were investigated. Two techniques including UV–Vis absorption spectroscopy and solution scanometry were applied for the analysis of MR content, comparatively. In spectrophotometric determination, the highest recovery was observed at pH 3.5 after 5 and 3 min of vortex time in the adsorption and desorption steps. The preconcentration factor of 75 and a wide linear concentration range (0.010 and 2.0 mg.L−1; R2 = 0.996) and low detection limit (LOD = 5.0 µg.L−1) with an acceptable precision (RSD = 3.4 %) was observed, too. Under optimum conditions in scanometric determination, a high preconcentration factor (i.e. 500) and similar linearity (0.010–2.0 mg.L−1; R2 = 0.989) and a low LOD of 3.1 µg.L−1, with the relative standard deviation of 1.4% was observed. Both techniques were used for MR recovery from various aqueous samples, successfully.

Renewable sorbent dispersive solid phase extraction automated by Lab-In-Syringe using magnetite-functionalized hydrophilic-lipophilic balanced sorbent coupled online to HPLC for determination of surface water contaminants

An automated methodology for magnetic dispersive solid phase microextraction integrating bead injection approach for renewable sorbent introduction is presented for the first time and was successfully applied to the enrichment of water contaminants. For this purpose, a simple procedure was developed for the functionalization of commercial SupelTM-Select HLB (Hydrophilic modified styrene polymer) sorbent beads that allowed embedding magnetite nanoparticles (Fe3O4). The sorbent was then used in a dispersive solid phase extraction procedure that was carried out entirely inside the void of an automatic syringe pump following the flow-batch concept of Lab-In-Syringe including automated renewal of the sorbent for each analysis. Mixing processes, sorbent dispersion, and sorbent recovery were enabled by using a strong magnetic stirring bar, fabricated from a 3D printed polypropylene casing and neodymium magnets, inside the syringe. The final extract was submitted to online coupled liquid chromatography with spectrometric detection. System and methodology were applied to determine mebendazole, bisphenol A, benzyl 4-hydroxybenzoate, diclofenac, and triclosan selected as models from different groups of environmental contaminants of current concern. Experimental parameters including extraction and elution times, composition and volume of eluent, and bead recollection were optimized. Required system elements were produced by 3D printing. Enlarging the sample volume by repeated extraction to enhance the sensitivity of the method was studied. Using double extraction from 3.5 mL, limits of detection ranged from 1.2 μg L−1 to 6.5 μg L−1 with an RSD (n = 6) value less than 7% for all the analytes at 25 μg L−1 level. The method was linear in the range of 5–200 μg L−1 and was successfully implemented for the analysis of surface waters with analyte recoveries ranging from 78.4% to 105.6%.

Sensitive determination of uranium using β-cyclodextrin modified graphene oxide and X-ray fluorescence techniques: EDXRF and TXRF

β-cyclodextrin/graphene oxide (GO-β-CD) was applied for dispersive micro-solid phase extraction (DMSPE) of uranyl ions (UO22+) from water samples and their determination by energy-dispersive (EDXRF) and total-reflection X-ray fluorescence spectrometry (TXRF). The structure of GO-β-CD was characterized by X-ray photoelectron spectroscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, and Raman spectroscopy. The results of batch adsorption experiment indicate that the maximum recoveries for UO22+ ions are observed at pH 4.5. The Langmuir isotherm model fits the adsorption data, which stands for the chemisorption mechanism. The obtained adsorption capacity of 87.7 mg g−1 indicates a great potential of the synthesized adsorbent in the UO22+ ions preconcentration. The GO-β-CD exhibits high resistance to high ionic strength (up to 2 mol L−1), indicating that high salinity samples can be treated with the evaluated preconcentration procedure. The obtained limit of detection values were 0.40 μg L−1 for the EDXRF and only 0.014 μg L−1 for TXRF analysis. The accuracy of the method was verified by analyzing certified reference material (spring water NIST-SRM 1640a) and spiked water samples (mineral, lake, river, and artificial sea water).

Novel Magnetic Molecularly Imprinted Polymer (MMIP) Based on a Magnesium-Aluminum Layered Double Hydroxide for the Selective Dispersive Micro-Solid-Phase Extraction (SPE) of Fenitrothion with Analysis by Ion Mobility Spectrometry

A novel magnetic molecularly imprinted polymer (MMIP) based on magnesium-aluminum layered double hydroxide was synthesized and employed for the selective dispersive micro-solid phase extraction of fenitrothion prior to its determination using ion mobility spectrometry. The characterization of the prepared MMIP was performed using x-ray diffraction spectroscopy, Fourier transform infrared spectroscopy, thermal gravimetric analysis, vibrating sample magnetometry, and field emission scanning electron microscopy (FE-SEM). The adsorption capacity of magnetic layered double hydroxide modified with molecularly imprinted polymer (mag-LDH@MIP) was 24.0 mg g−1. The factors affecting extraction efficiency were optimized. Using the optimized conditions, the developed method provided favorable linearity (5.0–200.0 μg L−1), a low limit of detection (1.1 μg L−1), and a high preconcentration factor (67). The values for the intra- and inter-day relative standard deviation (n = 5) for fenitrothion were 3.3 and 4.5%, respectively. This developed method was successfully employed to determine trace quantities of fenitrothion in food and water.

Determination of benzimidazoles in beef by molecularly imprinted boron nitride composite based dispersive solid phase microextraction and ultra performance liquid chromatography

The main objective of this study was to synthesize the molecularly imprinted boron nitride material and develop a high efficient method for extraction of the residue of veterinary drug in food sample. During the experiments, the molecularly imprinted microspheres with 2-aminobenzimidazole as the template were polymerize on boron nitride to synthesize a type of new composite. Then it was used as absorbent to develop a dispersive solid phase microextraction method for purification of benzimidazole drugs in beef followed by determination with ultra performance liquid chromatography. This composite could simultaneously recognize 7 benzimidazoles with high absorption capacity (36.23–38.88 μg/mg) and high recovery (92.3%-97.1%), and could be reused for 5 times. This sample extraction method achieved high enrichment factors (21.5–37.9), so the limits of detection for determination of the 7 drugs in beef were in the range of 0.2–0.5 ng/g. This is the first study reporting the use of boron nitride based material for the extraction of residual veterinary drug in food sample.

Application of a modified MWCNT-based d-µSPE procedure for determination of bisphenols in soft drinks

Herein, a facile dispersive micro-solid phase extraction (d-µSPE) procedure using carboxylated multi-walled carbon nanotubes modified with silver nanoparticles (Ag/MWCNTs-COOH) was successfully developed for the adsorption and subsequent determination of low levels of two well-known contaminants, namely bisphenol A and S (BPA and BPS) in water and soft drink samples. The detection and measurement of the above-mentioned compounds were performed by HPLC-UV instrument. The applied d-µSPE procedure has several advantages such as rapidity, high degree of sensitivity, precision and efficiency. A combination of polar/non-polar interactions seems to play a key role in the adsorption process. Under the optimized conditions, the calibration curves were linear over the concentration range of 1–500 µg/L for the both targets. The practical limit of quantifications (LOQ) for the both analytes were determined to be 1.0 µg/L. The average relative recoveries obtained from the fortified samples varied between 92 and 110% with the relative standard deviations (RSD%) of 2.9–9.5%.

Preparation of magnetic molecularly imprinted polymer based on multiwalled carbon nanotubes for selective dispersive micro-solid phase extraction of fenitrothion followed by ion mobility spectrometry analysis.

A novel molecularly imprinted polymer based on magnetic multiwalled carbon nanotubes was fabricated and applied for selective dispersive micro-solid phase extraction of fenitrothion prior its determination by ion mobility spectrometry. The composite was synthesized using magnetic multiwalled carbon nanotubes as the support. Methacrylic acid was used as the functional monomer, fenitrothion as the template, ethylene glycol dimethacrylate as the cross-linker, and 2,2-azoisobutyronitrile as the initiator. The resultant polymer was characterized by FTIR spectroscopy, X-ray diffraction, field emission scanning electron microscopy, Brunauer-Emmet-Teller analysis, thermogravimetric analysis, and vibrating sample magnetometer techniques. Experimental factors affecting the extraction efficiency such as pH and amount of sorbent were evaluated. Under optimum experimental conditions, the developed method displayed the linear range of 5-220 μg/L with a detection limit of 1.3 μg/L. The intra- and interday relative standard deviations for determination of fenitrothion were 3.6 and 4.7% (n=6), respectively. Ultimately, the proposed method was used to monitor trace amounts of fenitrothion in fruits, vegetables, and water samples.

A Simple Dispersive Micro-Solid Phase Extraction for Determination of Neonicotinoid Insecticides in Surface Water and Fruit Juice Samples

A dispersive micro-solid phase extraction (D-μ-SPE) has been investigated for simple microextraction and preconcentration of fi ve neonicotinoid insecticides residues followed by highperformance liquid chromatography. The neonicotinoid insecticides including thiamethoxam, clothianidin, imidacloprid, acetamiprid, and thiacloprid, were separated on LiChroprep® 100 RP-8 endcapped column using 25% (v/v) acetonitrile with a fl ow rate of 1.0 mL min−1. LiChroprep® RP-18 (C-18) was chosen as an effi cient adsorbent in d-μ-SPE. The experimental parameters affecting the extraction performance of D-μ-SPE were investigated including salt addition, amount of sorbent, sample volume, and kind and volume of desorption solvent. Under the selected conditions, linearity was found in the range of 0.003-0.1 μg mL−1. Low limit of detection and high enrichment factor (11 – 81) were obtained. The proposed method was successfully applied for the determination of neonicotinoid insecticide residues in surface water and fruit juice samples with high obtained recoveries.

In-syringe dispersive micro-solid phase extraction method for the HPLC-fluorescence determination of aflatoxins in milk

The simultaneous determination of aflatoxins (B 1 , B 2 , M 1 and M 2 ) in milk using a new sample pretreatment technique, the in-syringe dispersive micro-solid phase extraction (ISDμSPE), coupled with high performance liquid chromatography with fluorescence detection is described. The separation of the aflatoxins were performed using C18 Hypersil gold (250 mm × 4.6 mm, 5 μm) column at 40 °C under gradient elution for 35 min. The excitation and emission wavelengths of the fluorescence detector were at 360 nm and 440 nm, respectively. On-line photo-chemical derivatization was used to enhance the detection of aflatoxin B 1. Several parameters such as type and amount of sorbent, vortex speed, vortex time and elution solvent were evaluated. Limits of detection (LOD) ranged from 0.003 to 0.005 ng mL −1 , limits of quantification (LOQ) ranged from 0.01 to 0.02 ng mL −1 , recoveries ranged from 73.0 to 109.6%, and relative standard deviations (RSDs) was less than 17.3%. The proposed method was succesfully applied to the analysis of aflatoxins in milk. • An alternative microextraction procedure for the simultaneous determination of aflatoxin M 1 , M 2 , B 1 and B 2 in milk. • Samples and sorbent are dispersed in the syringe allowing higher surface area for interaction. • Acetone was used to replace hazardous chlorinated solvents.

Metal Organic Framework-Based Dispersive Solid-Phase Microextraction of Carbaryl from Food and Water Prior to Detection by Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry

In this work, metal organic frameworks (A100 Al-based MOFs) were used in dispersive solid-phase microextraction (DSPME) for the isolation and preconcentration of the carbaryl from vegetable, fruit and water samples. The A100 Al-based MOFs showed excellent behavior for the adsorption of carbaryl from a water–ethanol solution; additionally, carbaryl was easily desorbed with ethyl acetate for detection by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-TMS). The analytical process of DSPME together with UPLC-TMS provides the accurate monitoring of trace carbaryl residues. The results show that the optimal recovery% of carbaryl was obtained at a sample apparent pH of 5, with the application of 1 mL of ethyl acetate to elute the carbaryl from the A100 Al-based MOFs. The limit of detection (LOD) and the limit of quantification (LOQ) were 0.01 mg.L−1 and 0.03 mg.L−1, respectively. The RSD% was 0.8–1.9, and the preconcentration factor was 45. DSPME and UPLC-TMS were successfully used for the isolation and detection of carbaryl in food and water samples.

Development of dispersive solid-phase microextraction coupled with high-pressure liquid chromatography for the preconcentration and determination of the selected neonicotinoid insecticides

Neonicotinoid insecticides have raised a lot of societal concerns due to their environmental ubiquity and unique mode of action. Therefore, it is of great research interest to monitor their occurrence in the environmental waters. However, these compounds exist at low concentrations that is below instrument detection limits. This study reports the applicability of magnetic poly (3 aminobenzoic acid)-based activated carbon (Fe3O4@PABA/AC) composite as an adsorbent in dispersive magnetic solid-phase microextraction (d-MSPME) of neonicotinoid insecticides from wastewater and river water samples. The as-synthesized adsorbent was characterized and confirmed by Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, Brunauer–Emmett–Teller and X-ray diffraction spectroscopy. The analytes of interest were detected and quantified by high-performance liquid chromatography coupled with diode array detector (HPLC–DAD). The parameters affecting the extraction and preconcentration processes, such as pH, extraction time, mass of adsorbent, desorption time and eluent volume, were optimized using fractional factorial design and central composite design. Under optimum conditions, the limits of detection and quantification were in the ranges of 0.41–0.82 µg L−1 and 1.4–2.7 µg L−1, respectively. The linearity ranged from 1.4–700 µg L−1 with correlation of determination (R2) values varied between 0.9933 and 0.9987. The intra-day and inter-day precisions were 0.35–0.75% and 1.7–5.5%, respectively. The spike recovery experiments were conducted to evaluate the accuracy of the d-MSPME analytical method in real samples, and the percentage recoveries ranged from 86.7 to 99.2%. Therefore, this method shows great potential applicability in preconcentrating the pollutants from the environment.

Amin-modified graphene oxide as a promising adsorbent for selective extraction of dexamethasone adulterant from herbal supplements.

In most cases, herbal supplements found in illegal centers and herbal medicine stores have harmful content that causes irreparable damage to people. As a representative of the green chemistry method, a rapid and efficient dispersive micro solid-phase extraction (D-mSPE) method was applied to extract dexamethasone adulterant from handmade supplements sold as power natural enhancing materials. The quantification of the analyte was performed by high performance liquid chromatography with an ultraviolet detector. Effective parameters on the extraction recovery, including the type and amount of adsorbent, the kind of elution solvent, and the time of extraction and elution, were systematically investigated. The limit of detection of the method was 0.05 μg mL-1. Furthermore, inter-day precisions calculated as relative standard deviations were better than 10%. Ten dietary supplements, including liquid, capsule, tablet forms, and powder, were analyzed using the developed method, and four of them were detected as adulterated with dexamethasone. The developed method purifies the complex plant-based samples and results in a clean analysis with separation instruments.

Vortex- Assisted Dispersive Micro-Solid Phase Extraction Based on Nanostructured Imprinted Polymer: A Comparison Study between Spectrophotometric and Solution Scanometric Techniques

Vortex- Assisted Dispersive Micro-Solid Phase Extraction Based on Nanostructured Imprinted Polymer: A Comparison Study between Spectrophotometric and Solution Scanometric Techniques

Determination of Fumonisins in Edible Vegetable Oil by MIL-101(Cr) Based Dispersive Solid Phase Microextraction Combined with High Performance Liquid Chromatography Tandem Mass Spectrometry

Determination of Fumonisins in Edible Vegetable Oil by MIL-101(Cr) Based Dispersive Solid Phase Microextraction Combined with High Performance Liquid Chromatography Tandem Mass Spectrometry

Synthesis and application of new silver and sulfur decorated S-doped reduced graphene oxide in ultra-trace analysis of pesticides by ion mobility spectrometry.

In this research study, a novel, facile, and affordable method is presented for the synthesis of a Ag/S/S-RGO nanocomposite. The resulting new nanocomposite was identified by FT-IR, XRD, FESEM, XPS, BET and EDX and employed as a rapid and effective adsorbent with acceptable absorption capacity for the analysis of various pesticides by dispersive solid-phase microextraction combined with ion mobility spectrometry. The main experimental parameters of the method were optimized such as the type of desorption solvent, pH of the sample solution, type of buffer, amount of the sorbent (Ag/S/S-RGO), sorption/desorption time, etc. Under the optimized conditions, linear dynamic ranges of 0.5-110.0, 1.0-110.0, and 0.8-90.0 ng mL-1 were achieved, with limits of detection of 0.25, 0.35, and 0.25 ng mL-1 for simazine, alachlor, and haloxyfop, respectively. The relative standard deviations (RSD%) were obtained as <5.0%. Eventually, the method was utilized for the simultaneous determination of simazine, alachlor, and haloxyfop in environmental and agricultural samples with recoveries between 95.0 and 104.6%.

Ultrasound-assisted dispersive micro-solid phase extraction of Pb(II) in water samples with in situ synthesis of magnetic Fe3O4-PbS nanocomposites followed by electrothermal atomic absorption spectrometry determination

Herein, an ultrasound-assisted dispersive magnetic micro-solid phase extraction (DM-μSPE) approach, along with electrothermal atomic absorption spectrometry (ETAAS) for the determination of lead at trace level in spring, well, river mineral and tap water samples was developed. The extraction step is based on the synthesis of PbS, following the sonochemical decomposition of L-cysteine used as sulphide precursor and its anchoring onto bare magnetite nanoparticles yielding the Fe3O4@PbS nanocomposite. Overall, DM-μSPE with in situ precipitation of PbS and retention onto magnetic sorbent requires a time as short as 6 min. After trapping Pb(II) as PbS, the magnetic nanocomposite was easily separated from the aqueous matrix by applying an external magnetic field and analyzed by ETAAS following slurry sampling. Different parameters involved in both the sorbent preparation/extraction and Pb quantification were optimized. Under optimal conditions, the method showed a detection limit of 0.02 μg L−1 Pb and a quantification limit of 0.07 μg L−1 Pb. The repeatability, expressed as relative standard deviation was 2% (for 0.6 μg L−1; n = 3). An experimental enrichment factor of 79 and an extraction efficiency of 99% were obtained. Finally, the method was applied for the determination of ultratrace levels of Pb(II) in spring, well, river mineral and tap water samples, showing quantitative recoveries in the range of 95–100%.

Application of ZnS/S/S-RGO three-component nanocomposites in dispersive solid-phase microextraction coupled with ion mobility spectrometry for ultra-trace determination of multiclass pesticides.

A fast, effective, and sensitive dispersive solid-phase microextraction method coupled with ion mobility spectrometry for the simultaneous determination of bendiocarb, butachlor, and diazinon was developed using zinc sulfide/sulfur/sulfur-doped reduced graphene oxide (ZnS/S/S-RGO) nanocomposites. ZnS/S/S-RGO three-component nanocomposites were synthesized through a single-step solvothermal procedure, and their properties were characterized by FT-IR, XRD, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), and energy-dispersive x-ray spectroscopy (EDX). The influence of different parameters was optimized on the efficiency of the extraction including the type and the volume of desorption solvent, pH, type and the volume of buffer, the amount of absorbent, sorptionand desorption times. Under the optimal conditions, linear ranges were achieved 0.8-110, 1.0-110, and 0.5-100 ng mL-1 with detection limits of 0.32±0.01, 0.40±0.02, and 0.27±0.02 ng mL-1 for bendiocarb, butachlor, and diazinon, respectively. The method was employed for the ultra-trace determination ofthe three pesticides in water, rice, and soil samples with acceptable recovery values within the range 96.6±4.8-104.4±6.4%.

Novel adsorption material for solid phase extraction in sample pretreatment of plant hormones

植物激素在植物生长过程中具有重要作用,调节植物生长、发育及抗逆的各个过程。植物激素超微精准定量分析一直是植物生理学研究的瓶颈问题。植物激素的准确、高效检测目前大多是基于液相色谱-串联质谱联用技术。样品前处理是植物激素色谱-质谱分析中必不可少的一个步骤,直接影响后续检测方法的灵敏度和准确性。在植物激素各种前处理方法中,固相萃取(SPE)技术应用非常广泛。在萃取小柱基础上发展了多种新形式(分散固相萃取、磁性固相萃取、固相微萃取等,称之为SPE相关方法)。在上述SPE相关方法中,吸附材料的选择均是关键因素,决定了样品前处理过程的目标物提取、净化和富集效果。碳基材料(包括碳纳米管、石墨烯、碳氮化合物等)和有机骨架材料(包括金属有机骨架、共价有机材料)拥有结构可设计、比表面积大、稳定性良好等特性,非常适合作为吸附材料。分子印迹聚合物和超分子化合物依靠主-客体特异性分子识别作用,能显著提高样品前处理方法的选择性。本文重点针对植物激素样品前处理中的SPE技术,综述了近5年来上述几类功能化吸附材料的最新应用进展,并对其发展趋势进行展望。

Dispersive magnetic solid phase microextraction on microfluidic systems for extraction and determination of parabens

In this study, a customized microfluidic system was utilized for magnetic solid phase extraction of parabens. For this sake, magnetite nanoparticles were synthesized and coated with polyaniline to enable efficient extraction and magnetic separation of sorbents particles. The synthesized particles were extensively characterized in terms of morphology, composition, and magnetic properties. The utilized microfluidic platform consisted of a relatively long spiral microchannel fabricated through laser-cutting and multi-layered assembly. To obtain an efficient dispersion, simultaneous flows of sample solution and magnetic beads dispersion were introduced to the chip with the aid of two syringe pumps. In order to increase the stability of the dispersed nanoparticles in the aqueous solution, various chemical and instrumental parameters were investigated and optimized. In this context, exploitation of hydrophobic surfactants and surface charge manipulation of the particles was shown to be a highly promising approach for effective dispersion and maintenance of magnetic beads in long microfluidic channels. Under the optimized conditions, the calibration curves were linear in the range of 5.0–1000.0 μg L−1 for propyl paraben and 8.0–1000.0 μg L−1 for methyl- and ethyl paraben with coefficients of determination greater than 0.992. Relative standard deviations were assessed as intra- and inter-day values which were less than 7.2% and the preconcentration factors in water were 10–15 for 100 μg L−1 of parabens in water. Finally, the method was applied for the extraction of parabens from fruit juice, sunscreen, and urine samples which showed favorable accuracy and precision.

Determination of morphine, codeine, and thebaine concentrations from poppy seed tea using magnetic carbon nanotubes facilitated dispersive micro-solid phase extraction and GC-MS analysis

With tightening enforcement and restrictions amid the opioid epidemic, poppy seed tea is consumed as an alternative to mitigate the withdrawal symptoms or as a home remedy to relieve pain and stress. Previously published studies suggested the potential danger of consuming tea brewed with a moderate to a large amount of poppy seed. In this study, the effects of small quantity and repeat brewing on opiate concentrations were evaluated. A dispersive-micro solid phase extraction facilitated by magnetic carbon nanotubes (Mag-CNTs/d-µSPE) was developed, optimized, successfully validated, and applied to ten poppy seed tea samples using gas chromatography-mass spectrometry (GC-MS) analysis. A total of ten poppy seed samples were evaluated in this work. Two grams of bulk poppy seeds were brewed with 6 mL of heated and acidified DI water three times. The brewed tea samples were subjected to the validated Mag-CNTs/d-µSPE/GC-MS analysis. The total mean opiate concentrations obtained from three brews were 1.1–1926, 20.2–311, and 9.0–100 mg/kg for morphine, codeine, and thebaine, respectively. The total opiate yields obtained from the small quantity brewing, i.e., 6 g seed in 18 mL tea, in this study may provide minimal analgesic and euphoric effects. Over 80% of the total opiate yield was extracted in the first brew with acidified deionized water from the 10 min brewing period, and opiate yields from the second and third brew were minimal. However, potential overdose could occur for some tea samples when scaled up to the starter quantity of seed suggested for new users.