Solid-phase Microextraction Liquid Research Articles

Environmentally friendly and novel solid–liquid phase microextraction of maneb fungicide in fruits and vegetables

The dithiocarbamates class has been widely used in agriculture practices because of lower toxicity and instability than organophosphates and carbamates. Among them, the maneb has been used to produce several fruits and vegetables, but its high ingestion can adversely affect human health. This work developed the Solid-Liquid Phase Microextraction (SLPME) for extraction of the maneb in foods sample with posterior determination by Flow injection analysis-Flame Absorption Atomic Spectroscopy (FIA-FAAS). Curve analytical had a linear range from 0.9 to 20.0 µmol L−1 maneb (A = 5.94 × 10−4 C (µmol L−1) + 6.93 × 10−4), good repeatability (4.07%) and reproducibility (3.39%), limits of quantification (5.98 µmol L−1) and detection (0.197 µmol L−1), which was above of the established by regulatory agencies. The extraction of the maneb was performed using 685 µL of the solution of the 1.00 × 10−3 mol L−1 of EDTA, and it has excellent recovery values from 80.85 to 106.51%. Therefore, the developed SLPME demonstrated an alternative environmentally friendly for quickly extracting maneb from food samples (apple, papaya, and tomato).

Solid/liquid phase microextraction of five bisphenol-type endocrine disrupting chemicals by using a hollow fiber reinforced with graphene oxide nanoribbons, and determination by HPLC-PDA.

A novel solid/liquid phase microextraction (SLPME) technique was developed and applied to the simultaneous determination of five bisphenol-type endocrine disrupting chemicals (EDCs) including bisphenol A, bisphenol S, bisphenol F, bisphenol B and bisphenol AF. The method is based on the use of agraphene oxide nanoribbon-reinforced hollow fiber (GONRs-HF) and 1-octanol. GONRs were longitudinally unzipped from multiwalled carbon nanotubes (MWCNTs) by means of chemical oxidation and carefully characterized. GONRs were dispersed in ultrapure water with the assistance of surfactant and then immobilized into the wall pores of HF. Compared with CNTs, the hydrophilicity of GONRs was improved, and a uniform dispersion was formed. This simplifies the preparation process and reduces waste of materials. The pores and lumen of GONRs-HF were filled with 1-octanol, and then the whole assembly was used for the extraction of the analytes. In comparison with different extraction modes, GONRs-HF-SLPME exhibits a more effective extraction performance for five bisphenol-type EDCs. Response surface methodology was used to optimize experimental parameters affecting the extraction efficiency. The enrichment factors are in the range from 76 to 127 with good inter-fiber and batch-to-batch reproducibility. The method shows good linearity with determination coefficients (R2) higher than 0.9985. The limits of detection are in the range of 0.1-0.4μgL-1. Recoveries from spiked real samples are between 83% and 114% with relative standard deviations between 1.6% and 7.8%. Graphical abstract Schematic presentation of the preparation of graphene oxide nanoribbons (GONRs) with multiwalled carbon nanotubes (MWCNTs), immobilization of GONRs into the pores of hollow fiber (HF), and application for solid/liquid phase microextraction (SLPME) of five bisphenol-type endocrine disrupting chemicals in three kinds of real samples.

High-Throughput Solid-Phase Microextraction-Liquid Chromatography-Mass Spectrometry for Microbial Untargeted Metabolomics.

Nowadays, metabolomics data, when combined with other "omics" data, can provide important information regarding systems biology. Acquiring a comprehensive untargeted metabolome snapshot of complex sample matrices requires proper sample preparation, and access to sophisticated analytical instrumentation such as mass spectrometry. In metabolomics, sample preparation has substantial influence on the quality of the obtained metabolome profile. To achieve a real snapshot of the metabolome, the analysis method must be capable of inhibiting metabolite interconversion by immediately quenching all metabolome activity. Application of solid-phase microextraction (SPME), particularly in its in vivo set up, when undertaken in conjunction with a conscious selection of coating type based on the chosen sample matrix and the physicochemical properties of the analytes under study, is capable of providing extraction of representative metabolomes for many biological matrices. Metabolomes identified by SPME include low-abundance species and short-lived or unstable metabolites hardly captured by traditional extraction techniques. SPME coupled to liquid chromatography-high-resolution mass spectrometry has recently been introduced as an innovative alternative technique that integrates sampling, sample preparation, and extraction for metabolic profiling and isolation of candidate biomarkers. This chapter presents a detailed protocol for microbial metabolome analysis of Escherichia coli as a model organism, applying the high-throughput SPME-LC-MS workflow.

Hydrophilic modified magnetic multi-walled carbon nanotube for dispersive solid/liquid phase microextraction of sunitinib in human samples

In this paper, a novel approach for the efficient microextraction and determination of anticancer drug, sunitinib from human samples is described. We synthesized a new nanocomposite; honey coated magnetic multi-walled carbon nanotubes (Honey@magnetic-CNTs). This nanocomposite retains the magnetic properties of individual magnetic nanoparticles (MNPs) and can be effectively separated under an external magnetic field. The synthesized nanoparticles were characterized by FT-IR, VSM, EDAX and XRD and TEM studies. The spherical particles obtained before and after the functionalization had sizes of 14 nm and 16 nm, respectively. The method is based on Honey@magnetic-CNTs assisted dispersive solid-liquid phase microextraction for determination and analysis of the drug. The influences of experimental parameters were investigated. Under optimal conditions, the applied nanocomposite showed good performance, high sensitivity and fast extraction of the analyte from biological samples. In linearity test, the regression correlation coefficient was obtained more than 99% for analyte of interest and linear dynamic range for the proposed method was from 5 to 5000 ng mL−1. Method detection and quantification limits were 1.58 ng mL−1 and 5.28 ng mL−1, respectively. Relative standard deviation was 3.15%.

Capillary electrophoresis with online stacking in combination with AgNPs@MCM-41 reinforced hollow fiber solid-liquid phase microextraction for quantitative analysis of Capecitabine and its main metabolite 5-Fluorouracil in plasma samples isolated from cancer patients.

The purpose of this study is the development and validation of a simple, novel, selective and fast off-line microextraction technique combining capillary electrophoresis with in-column field-amplified sample injection (FASI) for the simultaneous determination of capecitabine (CAP) and its active metabolite, 5-Fluorouracil (5-FU), in human plasma. At the moment, there is a lack of using cost-effective CE tool combined with novel miniaturized sample clean-up techniques for analysis of these important anti-cancer agents in plasma samples. This paper intends to fill this gap and describe a simple off-line sample pretreatment by means of AgNPs@MCM-41 reinforced hollow fiber Solid/Liquid phase microextraction (AgNPs@MCM41-HF-SLPME) with subsequent quantitation by FASI-CE. The separation of analytes was performed using a BGE containing 60mM phosphate-Tris buffer (pH 7) with 10% methanol as an organic modifier. Before sample loading, a short water plug (50mbar, 3s) was injected to permit FASI for stacking. Various parameters affecting the off-line microextraction efficiency as well as FASI were optimized. Migration time was found to be 6.6 (±0.1)min for 5-FU and 7.4 (±0.2)min for CAP. The linearity, precision, accuracy, recovery, selectivity, specificity, stability as well as the robustness of the method was evaluated from spiked plasma samples during the course of validation. The results revealed that the presented technique demonstrates acceptable accuracy and precision, miniaturized sample preparation and a reduced need for complicated equipment along with an acceptable analysis time. The validated method was successfully applied to determine CAP and 5-FU in patient's plasma samples.

An innovative method for analysis of Pb (II) in rice, milk and water samples based on TiO2 reinforced caprylic acid hollow fiber solid/liquid phase microextraction.

In the present study, nano-sized titanium oxides were applied for preconcentration and determination of Pb(II) in aqueous samples using hollow fiber based solid-liquid phase microextraction (HF-SLPME) combined with flame atomic absorption spectrometry (FAAS). In this work, the nanoparticles dispersed in caprylic acid as an extraction solvent was placed into a polypropylene porous hollow fiber segment supported by capillary forces and sonification. This membrane was in direct contact with solutions containing Pb (II). The effect of experimental conditions on the extraction, such as pH, stirring rate, sample volume, and extraction time were optimized. Under the optimal conditions, the performance of the proposed method was investigated for the determination of Pb (II) in food and water samples. The method was linear in the range of 0.6-3000μgmL-1. The relative standard deviations and relative recovery of Pb (II) was 4.9% and 99.3%, respectively (n=5).

Green synthesis of magnetic iron nanoparticles coated by olive oil and verifying its efficiency in extraction of nickel from environmental samples via UV–vis spectrophotometry

In this research, we report the synthesis and functionalization of magnetic iron nanoparticles using green chemistry (olive oil) for application of dispersive solid–liquid phase microextraction (DSLME) as a novel method for preconcentration and determination of nickel ions in soil, potato, red tea, white tea, mushroom, lettuce, cabbage, apple, urban water, purified drinking water through household water treatment device. Nickel is a dangerous toxic metal that can cause serious damage to the environment and then its removal is necessary. Recently, iron oxide nano materials have gained much attention due to their properties, such as extremely small, non-toxic, excellent magnetic properties, high surface area, great biocompatibility and high level of reactivity with metal which makes them worthwhile in the removal of these metals. For optimizing the important parameters affecting the extraction procedure, analyte concentration, pH, type of disperser solvent, absorption time, ionic strength effect, type of desorption solvent and desorption time investigated. SEM and FT-IR spectrum used for characterization of the synthesized magnetic nanoparticles. The measurements were done under the optimized conditions. Matrices effect and accuracy were examined by the determination of the relative recovery (RR%) of the real samples. Linear range, detection limit and relative standard deviation (RSD) are 1–5000ng/ml, 0.821ng/ml and 0.196%, respectively.

Hollow fiber-based solid–liquid phase microextraction combined with theta capillary electrospray ionization mass spectrometry for sensitive and accurate analysis of methamphetamine

This paper presents a new method for analysis of methamphetamine based on hollow fiber-based solid–liquid phase microextraction coupled with theta capillary-electrospray ionization mass spectrometry detection.

Sensitive analysis of phthalate esters in plastic bottled water via on-line capillary solid-phase microextraction liquid chromatography electrospray ionization-ion trap mass spectrometry

An online capillary solid-phase microextraction coupled liquid chromatography electrospray ionization-ion trap mass spectrometry (cSPME-LC-ESI-IT-MS) has been developed and applied for analyzing six phthalate esters (PAEs) in commercially available plastic bottled water.

In vivo solid-phase microextraction liquid chromatography–tandem mass spectrometry for monitoring blood eicosanoids time profile after lipopolysaccharide-induced inflammation in Sprague-Dawley rats

A fast and non-lethal in vivo solid-phase microextraction (SPME) sampling method for rat blood coupled to liquid chromatography and tandem mass spectrometry (LC–MS/MS) was developed for monitoring rapid changes in concentrations of eicosanoids – lipid mediators involved in the development of inflammatory conditions – using diffusion-based calibration. Sampling rates of target eicosanoids were pre-determined under laboratory conditions with a precision of ≤10%, and directly used for quantification of analyte concentrations in blood after lipopolysaccharide-induced inflammation in Sprague-Dawley rats. Results showed significant changes in unbound plasma concentrations of arachidonic acid (AA) and 12-hydroxyeicosatetraenoic acid (12-HETE) in response to the treatment. Next, performance of the proposed method was compared with protein precipitation (PP) of plasma, a conventional sample preparation technique. Finally, percentages of plasma protein binding (PPB) of specific eicosanoids were determined. PPB of target eicosanoids was in agreement with literature values, ranging from 99.3 to 99.9% for 12-HETE and DHA, respectively. We envision that the proposed method is a particularly suitable alternative to lethal sampling and current methods based on sample depletion in animal studies for accurate monitoring of rapid changes in blood concentrations of small molecules.

Dispersive solid-liquid phase microextraction based on nanomagnetic Preyssler heteropolyacid: A novel method for the preconcentration of nortriptyline.

In this study, a new, simple, rapid, and efficient method combined with ultraviolet visible spectrophotometry and high-performance liquid chromatography analysis was developed for the extraction and determination of nortriptyline. The tendency of the Preyssler tungsten heteropolyacid, H14 [NaP5 W30 O110 ], immobilized on the surface of mesoporous nanomagnetite to adsorb the drug from the solution has been investigated. This method involves the use of an appropriate mixture of nanosorbent that was homogenized in disperser solvent (1.0 mL, ethanol). At first, the mixture containing the nanomagnetic sorbent and disperser solvent was injected into the aqueous sample, and a cloudy solution was formed. Subsequently, separation of the two phases was carried out using a magnet. In the second stage, analyte was desorbed from the sorbent by methanol as the optimal desorption solvent using sonication method. The elution solvent containing enriched analyte was introduced to the instruments for further analysis. Optimization of experimental conditions with respect to the extraction efficiency was investigated. The method was linear in the range of 25-5000, while the detection limit (LOD = 3SB /m) was 7.9 ng/mL and the limit of quantification (LOQ = 10SB /m) was 26.4 ng/mL. The relative standard deviation was 4.66%. The method was successfully applied to human hair samples.

PMIM]Br@TiO2 nanocomposite reinforced hollow fiber solid/liquid phase microextraction: an effective extraction technique for measurement of benzodiazepines in hair, urine and wastewater samples combined with high-performance liquid chromatography.

A new design of hollow fiber solid-liquid phase microextraction (HF-SLPME) was developed for the determination of benzodiazepines (BZPs) in hair, urine and wastewater. The membrane extraction with 1-pentyl-3-methylimidazolium bromide coated titanium dioxide ([PMIM]Br@TiO2) sorbent used in this research is a two-phase supported membrane extraction consisting of an aqueous (donor phase), and n-octanol/nano [PMIM]Br@TiO2 (acceptor phase) system operated in direct immersion sampling mode. The 1-pentyl-3-methylimidazolium bromide (ionic liquid) coated nano TiO2 dispersed in the organic solvent (n-octanol) is held into a porous membrane supported by capillary forces and sonification. It is in contact with the feed phase, which is the aqueous sample. The experimental setup is very simple and highly affordable. The hollow fiber is disposable, so single use of the fiber reduces the risk of cross-contamination and carry-over problems. The proposed method allows the very effective and enriched recuperation of BZPs into one single extract. In order to obtain high extraction efficiency of the analytes using this novel sorbent, the main parameters were optimized. Under the optimized extraction conditions, the method showed good linearity (0.05-6000ngmL(-1)), low limits of detection (0.08-0.5ngmL(-1)) and good enrichment (533-1190).

Extraction of Cu(II) Ions in Wastewaters Using New Solid/Liquid Phase Microextraction Technique Based on Incorporating Functionalized Carbon Nanotubes into Polypropylene Hollow Fiber

This research describes a new design of hollow fiber solid-liquid phase microextraction (HF– SLPME) which was developed for the extraction and measurement of Cu(II) ion in water samples combined with atomic absorption spectroscopy. This method consists of an aqueous feed and the functionalized multi-walled carbon nanotubes (F-MWCNTs) with HNO3 and NaClO, dispersed into n-octanol, are held within the pores and the lumen of a porous hollow fiber as the extractor phase. The presented method allows an effective and enriched recuperation of ionic analyte into MWCNTs/organic phase. The effective parameters were investigated. Under the optimized conditions, a sample of industrial waste water was successfully purified using the proposed method. Our results showed that at optimized extraction conditions, the calibration curve was linear in the range of 0.01 - 20 μg/mL of Cu(II) ions in the initial solution with R2 > 0.99 for both F-MWCNTs samples. All experiments were carried out at room temperature (25℃ ± 0.5℃).

Determination of Pentachlorophenol in Human Urine by Homemade Ionic liquid Solid-phase Microextraction Coating

A new method for the determination of pentachlorophenol(PCP) in human urine has been developed by headspace solid-phase microextraction with gas chromatography(HS-SPME-GC).A homemade ionic liquid(IL) bonded coating solid-phase microextraction was added by the sol-gel method.The extraction conditions were optimized as the extraction temperature of 80 ℃,extraction time of 50 min by headspace,desorption time of 5 min at 300 ℃,NaCl amount of 3 g,pH of 2 and under stirring.The detection limits was 5.0 ng/L.The linear range was 0.05-100 μg/L.The relative standard deviations(RSD) was 5.9%.The recovery was 106.6%.

Determination of Anilines Pollutant in Water by Monolithic Column-online Solid Phase Microextraction-Liquid Chromatography

For extraction column and valve system compatibility issues in on-line SPE-liquid chromatography analysis,we have built the large inner diameter extraction monolithic column compatible with liquid chromatography and related valve,pumping system.A large inner diameter(530 μm i.d.),uniform and stable silica monolithic capillary column has been prepared by using two hybrid precursor-tetramethoxysilane and methyltrimethoxysilane.After the modification of C 18 group,the results of frontier analysis show that the monolithic column has a larger adsorption capacity,wherein Ν-methylaniline is approximately 214 g/g,and N,N-Dimethylaniline is about 388 g/g.The column permeability is good,so the on-line solid phase extraction can be completed requires only the injection pump.The monolithic column was connected to the sample preparation equipment made by our laboratory and with the combination of liquid chromatography for online enrichment and separation,and it was applied to the determination of trace aniline categories compounds in river water.The mobile phase consisted of 15% methanol and 85% water solution in volume ratio;the flow rate for chromatographic separation was 0.5 mL/min;the detection wavelength was 254 nm.The recoveries were in the range of 81.9%-91.3%,and the relative standard deviation(RSDs) of intraday and interday were not larger than 7.6% at 0.1,1 and 10 g/L three spiked levels for all analytes.

Combination of New Solid/Liquid Phase Microextraction Technique Based on Functionalized Multiwalled Carbon Nanotubes with Flame Atomic Absorption Spectroscopy for the Extraction and Determination of Zn(II) in the Environmental Samples

A new design of equilibrium hollow fiber solid-liquid phase micro-extraction (HF–SLPME) was developed for the determination of Zn(II) in environmental water samples. Membrane extraction with sorbent interface which we used in this research is a two-phase supported liquid membrane consisting of aqueous (donor phase), organic solvent/nano sorbent membrane (acceptor phase) system operated in direct immersion sampling modes. Where the multiwalled carbon nanotube dispersed in the organic solvent is held in the pores of a porous membrane supported by capillary forces and sonification. All microextraction experiments were supported using an Accurel Q3/2 polypropylene hollow fiber membrane (600 μm I.D., 200 μm wall thicknesses, 0.2μm pore size). The experimental setup is very simple and highly affordable. Among most of micro-extraction techniques reported, it is the most effective sample preparation/preconcentration technique. The hollow fiber is disposable, so single use of the fiber reduces risk of crosscontamination and carry-over problems. The proposed method allows the very effective and enriched recuperation of ionic analyte into MWCNTs/organic phase. In order to obtain high enrichment and extraction efficiency of the analyte using this novel technique, the main parameters were optimized. Under the optimized extraction conditions, the method showed good linearity, repeatability, low limits of detection and very excellent enrichment factor (EF = 950).

Reusable Solid-Phase Microextraction Coating for Direct Immersion Whole-Blood Analysis and Extracted Blood Spot Sampling Coupled with Liquid Chromatography–Tandem Mass Spectrometry and Direct Analysis in Real Time–Tandem Mass Spectrometry

Three different biocompatible polymers were tested and evaluated in order to improve the whole-blood biocompatibility of previously developed C18-polyacrylonitrile (C18-PAN) thin-film solid-phase microextraction (SPME) coating. Among all methods of modification, UV-dried thin PAN-over C18-PAN provided the best results. This coating presented reusable properties and reproducible extraction efficiency for at least 30 direct extractions of diazepam from whole blood [relative standard deviation (RSD) = 12% using external calibration and 4% using isotope dilution calibration]. The amount of absolute recovery for direct immersion analysis and based on the free concentration of diazepam in blood matrix was about 4.8% (desorption efficiency = 98%). The limit of quantitation (LOQ) for the developed solid-phase microextraction liquid chromatography-tandem mass spectrometry (SPME-LC-MS/MS) method for direct whole-blood analysis was 0.5 ng/mL. The optimized modification of the coating was then used for an extracted blood spot (EBS) sampling approach, a new sampling method which is introduced to address the limitations of dried blood spot sampling. EBS was evaluated using LC-MS/MS and direct analysis in real time (DART)-MS/MS, where, for a 5 μL blood spot, LOQs of 0.2 and 1 μg/mL, respectively, were achieved for extraction of diazepam.

Determination of some organophosphorus pesticides in water and watermelon samples by microextraction prior to high-performance liquid chromatography

A novel method based on simultaneous liquid-liquid microextraction and carbon nanotube reinforced hollow fiber microporous membrane solid-liquid phase microextraction has been developed for the determination of six organophosphorus pesticides, i.e. isocarbophos, phosmet, parathion-methyl, triazophos, fonofos and phoxim, in water and watermelon samples prior to high-performance liquid chromatography (HPLC). Under the optimum conditions, the method shows a good linearity within a range of 1-200 ng/mL for water samples and 5-200 ng/g for watermelon samples, with the correlation coefficients (r) varying from 0.9990 to 0.9997 and 0.9986 to 0.9995, respectively. The limits of detection (LODs) were in the range between 0.1 and 0.3 ng/mL for water samples and between 1.0 and 1.5 ng/g for watermelon samples. The recoveries of the method at spiking levels of 5.0 and 50.0 ng/mL for water samples were between 85.4 and 100.8%, and at spiking levels of 5.0 and 50.0 ng/g for watermelon samples, they were between 82.6 and 92.4%, with the relative standard deviations (RSDs) varying from 4.5-6.9% and 5.2-7.4%, respectively. The results suggested that the developed method represents a simple, low-cost, high analytes preconcentration and excellent sample cleanup procedure for the determination of organophosphorus pesticides in water and watermelon samples.

Carbon nanotube reinforced hollow fiber solid/liquid phase microextraction: A novel extraction technique for the measurement of caffeic acid in Echinacea purpurea herbal extracts combined with high-performance liquid chromatography

A new design of hollow fiber solid–liquid phase microextraction (HF-SLPME) was developed for the determination of caffeic acid in medicinal plants samples as Echinacea purpure. The membrane extraction with sorbent interface used in this research is a three-phase supported liquid membrane consisting of an aqueous (donor phase), organic solvent/nano sorbent (membrane) and aqueous (acceptor phase) system operated in direct immersion sampling mode. The multi-walled carbon nanotube dispersed in the organic solvent is held in the pores of a porous membrane supported by capillary forces and sonification. It is in contact with two aqueous phases: the donor phase, which is the aqueous sample, and the acceptor phase, usually an aqueous buffer. All microextraction experiments were supported using an Accurel Q3/2 polypropylene hollow fiber membrane (600 μm I.D., 200 μm wall thicknesses, and 0.2 μm pore size). The experimental setup is very simple and highly affordable. The hollow fiber is disposable, so single use of the fiber reduces the risk of cross-contamination and carry-over problems. The proposed method allows the very effective and enriched recuperation of an acidic analyte into one single extract. In order to obtain high enrichment and extraction efficiency of the analyte using this novel technique, the main parameters were optimized. Under the optimized extraction conditions, the method showed good linearity (0.0001–50 μg/L), repeatability, low limits of detection (0.00005 μg/L) and excellent enrichment (EF = 2108).

Automated high-throughput method using solid-phase microextraction–liquid chromatography–tandem mass spectrometry for the determination of ochratoxin A in human urine

A new automated, high-throughput method for the determination of ochratoxin A (OTA) in human urine samples has been optimized and validated using solid-phase microextraction coupled to liquid chromatography-tandem mass spectrometry (SPME–LC–MS/MS). High-throughput was achieved by simultaneous preparation of up to 96 samples using multi-fiber SPME device and multi-well plates. A carbon-tape coating was chosen for the first time as the best extracting phase for this contaminant. The proposed method required only minimal sample pre-treatment to adjust sample pH to 3.0 using a dilution (1:1) with 0.5 M phosphate-buffered saline. A simple gradient guaranteed a good chromatographic separation from matrix interferences in only 8 min. Relative recovery (%), precision and linearity validation results met Food and Drug Administration acceptance criteria at three concentration levels (1, 10, and 50 ng/mL), indicating excellent performance of the proposed method. Limits of detection and quantitation were 0.3 and 0.7 ng/mL in urine, respectively. OTA determination in urine is a good marker for human exposure to this mycotoxin. It is also less invasive than blood analysis. This method is fully automated and the SPME technique is simpler, less time-consuming and cheaper compared with most widely adopted clean-up procedures for OTA extraction from urine.