Microextraction Approach Research Articles

Polydopamine-coated magnetic nanoparticles for the determination of nitro musks in environmental water samples by stir bar sorptive-dispersive microextraction

Magnetic-based microextraction approaches have gained popularity in recent years due to the magnetic properties of the extraction phases allowing to handle them easier and more efficiently. This work describes a magnetic-based analytical method for the determination of the family of nitro musks in environmental water samples. These compounds have been of great concern due to their environmental impacts and potential health effects. The method is based on stir bar sorptive-dispersive microextraction (SBSDME) as extraction approach, prior to thermal desorption coupled to gas chromatography-mass spectrometry analysis (TD-GC-MS). For this purpose, polydopamine-coated cobalt ferrite magnetic nanoparticles (CoFe2O4@PDA) were used as extraction material. The main parameters involved in the extraction procedure (i.e., sorbent amount, extraction time and ionic strength) as well as in the thermal desorption step (i.e., temperature and desorption time) were evaluated in order to obtain the highest sensitivity. Under the selected conditions, the method showed good linearity, limits of detection and quantification in the low ng L−1 range, intra- and inter-day repeatability with RSD <15%, and high enrichment factors (178–640). Finally, the method was applied to four environmental water samples of different origin. Relative recovery values ranging from 91 to 120% highlighted that the matrices under consideration do not affect the extraction process. This work constitutes the first time in which nitro musks compounds were selectively extracted by taking advantage the high potential that magnetic-based microextraction techniques offer, specially SBSDME.

A proof-of-concept of parallel single-drop microextraction for the rapid and sensitive biomonitoring of pesticides in urine.

In this study, a lab-made parallel single-drop microextraction methodology using the magnetic ionic liquid trihexyltetradecylphosphonium tetrachloromanganate (II) as extraction solvent was developed to determine the pesticides tebuconazole, pendimethalin, dichlorodiphenyltrichloroethane, and dichlorodiphenyldichloroethylene in human urine samples. The experimental setup consisted of a 96-well plate system containing a set of magnetic pins that allowed for the manipulation of up to 96 samples simultaneously, providing an enhanced drop stability compared to traditional single-drop microextraction approaches. The optimal conditions employed 5.38 ± 0.55mg of extraction solvent, 1.5mL of diluted urine samples (1:10), extraction time of 130min, and subsequent dilution in 20 μL of acetonitrile. The method exhibited satisfactory analytical performance, with limits of detection of 7.5μg/L for all analytes and coefficients of determination higher than 0.9955. Intraday and interday precisions ranged from 3 to 17% (n=3) and 15 to 18% (n=9), respectively, with relative recovery of analytes ranging from 70 to 122%. The method proposed was successfully applied in two human urine samples and no sign of the analytes was detected. The results demonstrated that the proposed method allowed for cost-effective and high-throughput methodology to be explored as a valuable tool in bioanalytical applications.

Smart materials for sample preparation in bioanalysis: A green overview

The analysis of biological samples is a complex challenge due to the complexity of the matrix, but also to the low concentration of target analytes that must be determined. Consequently, different sample treatment procedures have been proposed in bioanalysis to clean-up and enrich sample extracts, paying special attention to microextraction approaches. In this frame, the combined use of microextraction approaches with smart materials provides environmentally friendly sample treatment strategies with improved selectivity, sensitivity, and reusability. Applications of smart solid materials includes antibody–antigen interaction based materials, aptamers, molecularly imprinted polymers, metal organic frameworks, restricted access materials, carbon based nanomaterials, and magnetic nanoparticles. On the other hand, smart liquid materials used in sample preparation in bioanalysis comprise bio-based solvents, supramolecular solvents, ionic liquids, and deep eutectic solvents. Synthesis and applications of smart materials have been discussed under a Green Analytical Chemistry perspective.

Assessment of potentially toxic elements in vegetables and soil samples irrigated with treated sewage and human health risk assessment

ABSTRACT In this work, a new microextraction approach termed as vortex-assisted liquid phase microextraction based on deep eutectic solvent (VALPME-DES) combined with graphite furnace atomic absorption spectrometry (GFAAS) has been developed for the extraction, preconcentration and determination of potentially toxic elements (PTEs) in vegetables and soil samples irrigated with treated sewage from two different regions of Iran. The new DES was prepared by mixing a 1:1 molar ratio of choline chloride and citric acid monohydrate. Some effective parameters on extraction were studied and optimised. Under the optimum conditions, the repeatability and reproducibility of the VALPME-DES coupled with ETAAS for 5.0 µg L−1 of As(III) and 0.50 µg L−1 of Pb and Cd were determined to be 2.7–4.3 and 3.8–6.2%, respectively. The correlation coefficient (r2) of the calibration curves was in the range of 0.995–0.998. The limit of detections was in the range of 0.03 and 0.1 µg kg−1 for different metal ions. Linear range of 0.3 − 100 µg kg−1 for As(III) and, 0.03–200 µg kg−1 for Cd and Pb were obtained. The results showed among the target metals, the highest impact on the total value of non-carcinogenic risk was related to arsenic. Furthermore, the non-carcinogenic risk value for all vegetable types was lower than the permitted level. We also found that the risk of arsenic carcinogenicity was higher than the acceptable levels in all four types of vegetables. According to the findings, interventions to reduce arsenic should be used, especially in cultivated soils.

In-a-syringe surfactant-assisted dispersive liquid-liquid microextraction of polycyclic aromatic hydrocarbons in supramolecular solvent from tea infusion

In this work, an automated surfactant-assisted dispersive liquid-liquid microextraction approach based on in-a-syringe concept was developed for the first time. The procedure assumed mixing aqueous sample phase and hydrophilic emulsion containing hexanoic acid and sodium hexanoate in a syringe of flow system. Sodium hexanoate acted as an emulsifier in dispersive liquid-liquid microextraction process and it was required for the formation of supramolecular solvent phase. After spontaneous separation of phases in the syringe, the upper supramolecular solvent phase containing target analytes was withdrawn and analyzed. The procedure was applied to the determination of 13 polycyclic aromatic hydrocarbons in tea infusion by high performance liquid chromatography with fluorescence detection. It was shown that the supramolecular solvent provided effective extraction of polycyclic aromatic hydrocarbons and fast phase separation in the syringe without centrifugation. The enrichment factors were in the range of 38–46. The automated microextraction procedure lasted 4 min including syringe cleaning. Under optimal experimental conditions the linear detection ranges were found to be 0.05–50.00 μg L−1 with limits of detection calculated from a blank test, based on 3σ, 0.02–0.04 μg L−1. Recovery values in the range of 85–105% were achieved for tea infusion with a reproducibility expressed as RSD less than 4.1%.

Analysis of food samples made easy by microextraction technologies directly coupled to mass spectrometry.

Because of the complexity and diversity of food matrices, their chemical analysis often entails several analytical challenges to attain accurate and reliable results, especially for multiresidue analysis and ultratrace quantification. Nonetheless, microextraction technology, such as solid-phase microextraction (SPME), has revolutionized the concept of sample preparation for complex matrices because of its nonexhaustive, yet quantitative extraction approach and its amenability to coupling to multiple analytical platforms. In recent years, microextraction devices directly interfaced with mass spectrometry (MS) have redefined the analytical workflow by providing faster screening and quantitative methods for complex matrices. This review will discuss the latest developments in the field of food analysis by means of microextraction approaches directly coupled to MS. One key feature that differentiates SPME-MS approaches from other ambient MS techniques is the use of matrix compatible extraction phases that prevent biofouling, which could drastically affect the ionization process and are still capable of selective extraction of the targeted analytes from the food matrix. Furthermore, the review examines the most significant applications of SPME-MS for various ionization techniques such as direct analysis in real time, dielectric barrier desorption ionization, and some unique SPME geometries, for example, transmission mode SPME and coated blade spray, that facilitate the interface to MS instrumentation.

Sample preparation strategies for the determination of psychoactive substances in biological fluids

This review focuses on the existing analytical procedures for the determination of new psychoactive substances (NPS) in biological fluids by chromatographic methods. Direct analysis of samples is scarcely employed and most proposed methodologies include a sample pre-treatment in order to remove matrix interferents and, in some cases, pre-concentrate extracts. Current extraction methods for NPS determination in plasma/serum, urine, and oral fluids have been widely discussed, such as liquid-liquid, solid-phase, and micro extraction approaches, highlighting the advantages and drawbacks of the proposed extraction methodologies. Regarding microextraction approaches, techniques like microextraction by packed sorbent, solid-phase microextraction, miniaturized solid phase extraction, and dispersive liquid-liquid extraction have been proposed for NPS determination in biological fluids with reliable analytical results.

Flame atomic absorption spectrometric determination of total chromium and cadmium in bean samples after ultrasonic-assisted microextraction using ionic liquid Aliquat-336

A new and rapid microextraction approach termed as ultrasonic-assisted ionic liquid-based microextraction (UA-ILME) was developed using ionic liquid Aliquat-336 as extraction solvent for the extraction of chromium and cadmium in bean samples collected from different regions in Turkey. The total amounts of analytes in the samples were measured by flame atomic absorption spectrophotometry. The basis of the extraction step is based on the complexation of Cr(III) and Cd(II) with diethyldithiocarbamate at pH 4.0. The hydrophobic ternary complexes containing analytes were then rapidly extracted from the sample solution to the ionic phase under the ultrasonic effect using tricaprylylmethylammonium chloride (Aliquat-336). Some experimental variables (pH, ligand amount, extraction solvent volume, ultrasound time, extraction temperature and sample volume) were optimized in detail. Following the optimization steps, the limits of detection (LODs, 3Sblank/m) for Cr(III) and Cd(II) were calculated as 0.45 ng mL−1 with linear range of 1.5–380 ng mL−1 and 0.25 ng mL−1 with linear range of 0.8–220 ng mL−1, respectively. Enrichment factors and average recoveries were ranged from 125.8–96.4 to 92.7–106.5%, respectively. The accuracy and precision of the method were validated by analyzing a certified reference material and spiked recovery tests. The UA-ILME method was successfully applied to the determination of Cd and Cr in the samples, highlighting that the matrix ions under consideration do not affect the extraction and determination steps.

A new approach for microextraction of trace albendazole sulfoxide drug from the samples of human plasma and urine, and water by the molecularly imprinted polymer nanoparticles combined with HPLC

In this research study, a method of dispersive-micro-solid phase extraction (D-µ-SPE) combined with molecularly imprinted polymer nanoparticles (MIP-NPs) with HPLC-UV was developed for the fast and selective detection of the trace amount of albendazole sulfoxide (ABZSO) in the biological samples. To investigate the effective factors on ABZSO microextraction by the method, central composite design (CCD) was utilized, and the optimum conditions for ABZSO microextraction were sample pH of 8.0, MIP-mass of 15 mg, sonication time of 12 min, and eluent (methanol) volume of 0.25 mL. Under the obtained optimal extraction conditions, the value for the limit of detection (LOD) and limit of quantification (LOQ) was respectively showed to be 0.074 and 0.246 ng mL−1. In addition, the calculated peak areas exhibited a linear relationship with the ABZSO concentration ranging from 0.4 to 4200 ng mL−1. The analyses of the samples including human plasma and urine, and water were successfully performed by the usage of the D-µ-SPE method, which was a simple and sensitive technique and a suitable alternative for the analysis of ABZSO. In the analysis of ABZSO in various samples, the recoveries at various levels of ABZSO concentrations (50, 300, and 500 ng mL−1) were in the range of 95.7–103.0 %, and the relative standard deviations (RSDs; n = 3) varied from 2.2 to 4.4%.

Application of temperature-assisted tandem dispersive liquid–liquid microextraction for the extraction and high preconcentration of triazole pesticides

ABSTRACT An efficient and reliable sample pretreatment approach termed as temperature-assisted tandem dispersive liquid–liquid microextraction has been developed for the extraction of five triazole pesticides from aqueous samples prior to their quantification by gas chromatography–flame ionisation detection. The suggested approach comprises two successive dispersive liquid–liquid microextraction approach. For performing procedure, the first temperature of high volume of aqueous solution is thermostated at an elevated temperature and after that, the mixture of disperser and extraction solvents is quickly injected into it. After cooling the solution with tap water, phase isolation is hastened by centrifuging. The whole of sedimented phase is taken and after mixing with another disperser solvent is employed in the following microextraction approach. The validation outcomes indicated that the approach provided low limits of detection and quantification (0.08–0.13 and 0.24–0.48 ng mL−1, respectively). Extraction recoveries and enrichment factors and were in the ranges of 97–100%and 9715–9970, respectively. Relative standard deviations were ≤6%. At the end, several aqueous samples were analysed employing the suggested approach and penconazole and hexaconazole were detected in them.

Nanoliter-Scale Droplet-Droplet Microfluidic Microextraction Coupled with MALDI-TOF Mass Spectrometry for Metabolite Analysis of Cell Droplets.

The further miniaturization of liquid-phase microextraction (LPME) systems has important significance and major challenges for microscale sample analysis. Herein, we developed a rapid and flexible droplet-droplet microfluidic microextraction approach to perform nanoliter-scale miniaturized sample pretreatment, by combining droplet-based microfluidics, robotic liquid handling, and LPME techniques. Differing from the previous microextraction methods, both the extractant and sample volumes were decreased from the microliter scale or even milliliter scale to the nanoliter scale. We utilized the ability of a liquid-handling robot to manipulate nanoliter-scale droplets and micrometer-scale positioning to overcome the scaling effect difficulties in performing liquid-liquid extraction of nanoliter-volume samples in microsystems. Two microextraction modes, droplet-in-droplet microfluidic microextraction and droplet-on-droplet microfluidic microextraction, were developed according to the different solubility properties of the extractants. Various factors affecting the microextraction process were investigated, including the extraction time, recovery method of the extractant droplet, static and dynamic extraction mode, and cross-contamination. To demonstrate the validity and adaptability of the pretreatment and analysis of droplet samples with complex matrices, the present microextraction system coupled with MALDI-TOF mass spectrometry (MS) detection was applied to the quantitative determination of 7-ethyl-10-hydroxylcamptothecin (SN-38), an active metabolite of the anticancer drug irinotecan, in 800-nL droplets containing HepG2 cells. A linear relationship (y = 0.0305x + 0.376, R2 = 0.984) was obtained in the range of 4-100 ng/mL, with the limits of detection and quantitation being 2.2 and 4.5 ng/mL for SN-38, respectively.

The Automation Technique Lab-In-Syringe: A Practical Guide.

About eight years ago, a new automation approach and flow technique called “Lab-In-Syringe” was proposed. It was derived from previous flow techniques, all based on handling reagent and sample solutions in a flow manifold. To date Lab-In-Syringe has evidently gained the interest of researchers in many countries, with new modifications, operation modes, and technical improvements still popping up. It has proven to be a versatile tool for the automation of sample preparation, particularly, liquid-phase microextraction approaches. This article aims to assist newcomers to this technique in system planning and setup by overviewing the different options for configurations, limitations, and feasible operations. This includes syringe orientation, in-syringe stirring modes, in-syringe detection, additional inlets, and addable features. The authors give also a chronological overview of technical milestones and a critical explanation on the potentials and shortcomings of this technique, calculations of characteristics, and tips and tricks on method development. Moreover, a comprehensive overview of the different operation modes of Lab-In-Syringe automated sample pretreatment is given focusing on the technical aspects and challenges of the related operations. We further deal with possibilities on how to fabricate required or useful system components, in particular by 3D printing technology, with over 20 different elements exemplarily shown. Finally, a short discussion on shortcomings and required improvements is given.

In-situ synthesis of flower like Co3O4 nanorod arrays on anodized aluminum substrate templated from layered double hydroxide as a nanosorbent for thin film microextraction of acidic drugs followed by HPLC-UV quantitation

The present study is the first report of in-situ growth and application of nanorods-flower like Co3O4 nanosorbent coated on the anodized aluminum substrate for thin film microextraction (TFME) approach. The flower like Co3O4 was successfully fabricated by conversion of Co-Al layered double hydroxide (LDH) precursor to Co3O4 using the simple calcinations process. The cheap and available aluminum foil was electrochemically anodized and used as a porous substrate. Response surface methodology (RSM) was explored for optimization step. Different acidic drugs, including: paracetamol, ibuprofen, aspirin and diclofenac were extracted from biological fluids in order to investigate the capability of the prepared sorbent. The extracted analytes were then analyzed using high performance liquid chromatography-ultraviolet detection (HPLC-UV). Under the optimized conditions, the limits of detection were between 0.2 and 1.7 µg L−1 in different selected matrices. The obtained limits of quantification were also calculated to be between 0.8 and 5.1 µg L−1 in the selected matrices. In addition the enrichment factors were also in the range of 105–169. Batch-to-batch reproducibility at 100 µg L−1 concentration level was also evaluated to be lower than 5.2% (n = 3). Finally, the method was successfully used for analysis of these compounds in the biological fluids.

A Fast and Validated High Throughput Bar Adsorptive Microextraction (HT-BAµE) Method for the Determination of Ketamine and Norketamine in Urine Samples.

We developed, optimized and validated a fast analytical cycle using high throughput bar adsorptive microextraction and microliquid desorption (HT-BAμE-μLD) for the extraction and desorption of ketamine and norketamine in up to 100 urine samples simultaneously, resulting in an assay time of only 0.45 min/sample. The identification and quantification were carried out using large volume injection-gas chromatography-mass spectrometry operating in the selected ion monitoring mode (LVI-GC-MS(SIM)). Several parameters that could influencing HT-BAµE were assayed and optimized in order to maximize the recovery yields of ketamine and norketamine from aqueous media. These included sorbent selectivity, desorption solvent and time, as well as shaking rate, microextraction time, matrix pH, ionic strength and polarity. Under optimized experimental conditions, suitable sensitivity (1.0 μg L−1), accuracy (85.5–112.1%), precision (≤15%) and recovery yields (84.9–105.0%) were achieved. Compared to existing methods, the herein described analytical cycle is much faster, environmentally friendly and cost-effective for the quantification of ketamine and norketamine in urine samples. To our knowledge, this is the first work that employs a high throughput based microextraction approach for the simultaneous extraction and subsequent desorption of ketamine and norketamine in up to 100 urine samples simultaneously.

Optimization of thin film solid phase microextraction and data deconvolution methods for accurate characterization of organic compounds in produced water.

The continued rise in the extraction of unconventional oil and gas across the globe poses many questions about how to manage these relatively new waste-streams. Produced water, the primary waste by-product, contains a diverse number of anthropogenic additives together with the numerous hydrocarbons extracted from the well. Due to potential environmental hazards, it is critical to characterize the chemical composition of this type of waste before properdisposalor remediation/reuse. In this work, a thin film solid phase microextraction approach was developed and optimized to characterize produced water. The thin film device consisted of hydrophilic-lipophilic balance particles embedded in polydimethylsiloxane and immobilized on a carbon mesh surface. These devices were chosen to provide broad extraction coverage and high reusability. Various parameters were evaluated to ensure reproducible results while minimizing analyte loss. This optimized protocol, consisting of a 15min extraction followed by a short (3 s) rinsing step, enabled the reproducible analysis of produced water without any sample pretreatment. Extraction efficiency was suitable for both produced water additives and hydrocarbons. The developed approach was able to tentatively identify a total of 201 compounds from produced water samples, by using one-dimensional gas chromatography hyphenated to mass spectrometry and data deconvolution.

High-throughput microscale extraction using ionic liquids and derivatives: A review.

Ionic liquids and derivatives-mainly polymeric ionic liquids and magnetic ionic liquids-have been extensively used in microscale extraction over the past few years. Current trends in analytical sample preparation gear toward linking microextraction approaches with high-throughput sample processing to comply with green analytical chemistry requirements. A variety of high sample throughput strategies that are coupled to both ionic-liquid-based solid-phase microextraction and ionic liquid-based liquid-phase microextraction are herein reported. The review is focused on microscale extraction methods that use (i) custom-made and dedicated extraction devices, (ii) parallel extraction, (iii) magnetic-based separation, and (iv) miniaturized systems employing semi-automatic or fully automatic flow injection methods, related micro/millifluidic devices, and robotic equipment.

Alcohol-DES based vortex assisted homogenous liquid-liquid microextraction approach for the determination of total selenium in food samples by hydride generation AAS: Insights from theoretical and experimental studies

This research article proposes a simple, quick, green and cheap approach for the determination of total selenium in food samples using alcohol-DES based vortex-assisted homogenous liquid-liquid microextraction (alcohol-DES-VA-HLLME) combination with hydride generation atomic absorption spectrometry (HG AAS). Analyte, complexing agent and working pH were Se(IV), Sudan-II and pH 4.0, respectively. In order to analyze the nature of the chemical interaction between Se(IV) ion and Sudan-II ligand, experimental results were supported with computational chemistry tools calculating quantum chemical descriptors like frontier orbital energies, hardness, softness, electronegativity, electrophilicity, nucleophilicity, transferred electron from the ligand to ion, electron donating power, electron accepting power, complexation energy, molecule-ion interaction energy. In addition, the alcohol-DES-VA-HLLME method was earned a good detection limit of 3.5 ng L−1 and a wide calibration curve in the concentration range of 12–300 ng L−1 (r: 0.9981). The validity of the method was evaluated by analyzing the two standard reference material (SRMs). The recoveries and relative standard deviations for 25 and 100 ng L−1 of Se(IV) (N:5) were in the range of 1.2–2.5% and 92.1–103.7% respectively, which proved acceptable. The analytical results showed that the proposed method had important features such as cheapness, green, quick extraction and reuse, which made it attractive for the determination and efficient extraction of total selenium in the food samples.

Recent advances in the application of thin-film microextraction

Thin-film microextraction (TFME), which is a new technique in solid-phase microextraction and correlational research, have gradually attracted the attention of scientists in the field of sample preparation. Because of the high surface area-to-volume ratio and the concurrent increase inthe extraction-phase volume, TFME shows enhanced sensitivity without sacrificing the sampling time, as opposed to other microextraction approaches. Recently, TFME in combination with sample analysis techniques has been widely used for the analysis of forbidden drugs, explosives, pesticides, and veterinary drugs in the pharmaceutical, foodstuff, and environmental industries. This review summarizes the fundamentals, formats, and applications of TFME, as well as its long-term prospects and potential applications.

Smartphone-based on-cell detection in combination with emulsification microextraction for the trace level determination of phenol index

In this study, a simple and portable device based on smartphone detection was developed for the determination of ppb levels of phenol index. The method was a combination of emulsification microextraction and smartphone sensing. The device consisted of a pycnometer as both extraction vial and detection cell, and a smartphone as a detector and data processing unit. Phenol was reacted with 4-aminoantipyrine in the sample solution to produce a colored compound. The colored product was extracted through an emulsification microextraction approach. Then, analyte quantification was performed using smartphone-based on-cell detection. The effect of key experimental factors on the method sensitivity was studied. The optimized method showed a linear range of 5–100 µg L−1 with the detection limit and the quantification limit of 2 and 5 µg L−1, respectively. The method provided the accurate and reproducible determination of phenol index in water and wastewater samples. The recoveries higher than 89% with relative standard deviations lower than 7% were obtained. The method required no external power supply or any complicated instrument, which made it a portable device suitable for field analysis.

Determination of quercetin via thin film microextraction using the in situ growth of Co–Al-layered double hydroxide nanosheets on an electrochemically anodized aluminum substrate followed by HPLC

The present study explains the in situ growth of Co–Al layered double hydroxide coated on an anodized aluminum substrate for thin film microextraction (TFME) approach.