Sorbent-based Microextraction Research Articles

A 96-position platform for magnetic sorbent-based dispersive microextraction: Application to the determination of tetrahydrocannabinol and cannabidiol in saliva of cannabis smokers

BackgroundIn order to obtain sustainable analytical methods, it is essential to develop kinetically efficient sample preparation strategies in which equilibria are reached faster, as dispersive extraction techniques. In addition, the higher the reduction in size, the higher number of extraction vessels can be located and thus the higher number of samples can be simultaneously treated. All this increases sample throughput, and contributes to the reduction of chemical waste, and energy and sample consumption. In this sense, multiposition extraction platforms are smart strategies to achieve these goals, but they are scarcely developed for dispersive extraction techniques. ResultsTaking miniaturized stir bar sorptive dispersive microextraction (mSBSDME) as a starting point, a 96-position extraction platform has been developed using a 96-position stirring plate and a tailor-designed 3D-printed support for locating the miniaturized extraction vessels, achieving a high-throughput miniaturized sample preparation strategy. In order to show the applicability of this novel platform, the determination of Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) in human saliva has been carried out and applied to samples collected after the consumption of marijuana and legal CBD-rich cannabis. Only 100 μL of saliva were needed for the analysis and good analytical features in terms of linearity (at least up to 500 ng mL−1), limits of detection (0.7 and 2.8 ng mL−1 for THC and CBD, respectively), and precision (RSD ≤ 14 %) were achieved. SignificanceThe miniaturization of the vessel allows the use of small volumes of sample (i.e., a few microliters) and the treatment of 96 samples in parallel, being the first proposal for carrying out dispersive sorbent-based microextraction under the concept of 96-well format. Additionally, this new workflow contributes to the development of analytical methods that meet the three pillars of sustainability, i.e., greenness and easily affordable in terms of economics and applicability.

Current Development in Bioanalytical Sample Preparation Techniques

The preparation of the sample is the most important stage in bioanalysis. Proteins, salts, and other organic compounds with chemical characteristics similar to the target analytes are commonly found in biological samples. As a result, sample preparation is an essential step that improves matrix suitability for analysis in multiple ways, including by separating the analytes and clearing the matrix of obstructive elements. Innovative sample preparation techniques have been more and more popular over the last 10 years due to their advantages over conventional techniques in terms of accuracy, automation, simplicity of sample preparation, storage, and delivery. This article’s goal is to raise awareness of the most recent advancements in the processing of bioanalytical samples. Different extraction stages are provided by modern techniques, such as sorbent-based microextraction, and the advantages of bioanalytical approaches have been highlighted.

Capsule Phase Microextraction Combined with Chemometrics for the HPLC Determination of Amphotericin B in Human Serum

This article discusses the use of a sorbent-based microextraction technique employing a capsule device to isolate amphotericin B (AMB) from human serum before analysis by high performance liquid chromatography (HPLC). AMB is a macrocyclic compound used for the treatment of invasive fungal infections. Before determining AMB in human serum by HPLC, a sample preparation step is required. Capsule phase microextraction (CPME) integrates the stirring and filtration mechanisms in a single unit, simplifying the sample preparation procedure. Moreover, it results in fast extraction kinetics and high extraction efficiency, while it has proved to be a powerful tool for bioanalysis. Different sol–gel sorbent encapsulated microextraction capsules were investigated, and sol–gel Carbowax 20 M was finally chosen as the basis for the microextraction device. Accordingly, the sample preparation protocol was investigated using a face-centered central composite design to achieve good extraction performance. The optimum protocol was validated in terms of linearity, selectivity, limit of detection (LOD), limit of quantitation (LOQ), precision, and accuracy. The linear range of the developed approach was 0.10–10.0 μg mL−1. The LOD value was 0.03 μg mL−1, and the LOQ value was 0.10 μg mL−1. Method accuracy (expressed as relative recovery) was 87–113%, while the relative standard deviation of the repeatability (sr) and within-laboratory reproducibility (sR) were <12.4%. The sol–gel sorbent encapsulated microextraction capsules were reusable for at least 10 extraction cycles. All things considered, the proposed method exhibited good overall performance, and it could be used in bioanalysis for quality control, therapeutic drug monitoring and research purposes.

Bio-Nanohybrid Composite Sorbent-Based Microextraction Combined with High-Performance Liquid Chromatography for NSAIDs in Aqueous Samples

Bio-Nanohybrid Composite Sorbent-Based Microextraction Combined with High-Performance Liquid Chromatography for NSAIDs in Aqueous Samples

Combination of fabric phase sorptive extraction with UHPLC-ESI-MS/MS for the determination of adamantine analogues in human urine

Herein, fabric phase sorptive extraction – a member of sorbent-based microextraction family – is utilized for the rapid isolation of selected antiviral drugs namely amantadine, memantine and rimantadine from human urine prior to their analysis with UHPLC-MS/MS. Fabric phase sorptive extraction membrane coated with sol–gel sorbent coated poly(propylene glycol)-poly(ethylene glycol)-poly(propylene glycol) sorbent was identified as the optimum extraction membrane for the target analytes. Due to the engineered affinity of the fabric phase sorptive extraction towards the analytes, the extraction proceeds in relatively short time (20 min) while its high permeability permits the extraction of biological samples without any other pretreatment. Following selection of the appropriate membrane, significant parameters including extraction time, sample volume, membrane size, elution solvent, etc were optimized. The drugs were analyzed under positive electrospray ionization using multi-reaction monitoring mode. The method was linear in the range of 5 – 100 ng mL−1 by constructing weighted matrix-matched calibration curves. The intra-day and inter-day accuracy were ranged between – 18.7 to + 18.1% and – 18.3 to + 16.1%, respectively. The precision of the method (intra-day, inter-day) were less than 18.5 % in all cases. The method limits of detection were in the range of 0.2 – 0.8 ng mL−1 while the lower limit of quantitation was set at 5 ng mL−1 for all analytes. The developed analytical scheme was efficiently applied to the analysis of the target drugs in human urine and could be adopted as a rapid and robust green analytical tool for clinical applications.

Recent Advances in Sample Preparation for Cosmetics and Personal Care Products Analysis.

The use of cosmetics and personal care products is increasing worldwide. Their high matrix complexity, together with the wide range of products currently marketed under different forms imply a challenge for their analysis, most of them requiring a sample pre-treatment step before analysis. Classical sample preparation methodologies involve large amounts of organic solvents as well as multiple steps resulting in large time consumption. Therefore, in recent years, the trends have been moved towards the development of simple, sustainable, and environmentally friendly methodologies in two ways: (i) the miniaturization of conventional procedures allowing a reduction in the consumption of solvents and reagents; and (ii) the development and application of sorbent- and liquid-based microextraction technologies to obtain a high analyte enrichment, avoiding or significantly reducing the use of organic solvents. This review provides an overview of analytical methodology during the last ten years, placing special emphasis on sample preparation to analyse cosmetics and personal care products. The use of liquid–liquid and solid–liquid extraction (LLE, SLE), ultrasound-assisted extraction (UAE), solid-phase extraction (SPE), pressurized liquid extraction (PLE), matrix solid-phase extraction (MSPD), and liquid- and sorbent-based microextraction techniques will be reviewed. The most recent advances and future trends including the development of new materials and green solvents will be also addressed.

Solvent-loaded metal-organic framework of type MIL-101(Cr)-NH2 for the dispersive solid-phase extraction and UHPLC-MS/MS analysis of herbicides from paddy field waters.

A novel solvent-loaded dispersive solid-phase extraction (SL-DSPE) method integrated with liquid-phase microextraction (LPME) has beendeveloped by the direct loading of solvent into the pores of a metal-organic framework (MOF), MIL-101(Cr)-NH2. Despite numerous advantages of MOFs, they are usually highly hydrophobic which limits their dispersibility and therefore effective contact with the analytes in aqueous samples. To overcome this and promote its interactions with polar compounds, MIL-101(Cr) was functionalized with -NH2 and loaded with a comparatively polar organic solvent, dichloromethane. The purpose of dichloromethane was to condition the MIL-101(Cr)-NH2, promote LPME of the analytes and facilitate the re-collection of the materials after the extraction. Five chlorophenoxy acid herbicides, including 2,4-dichlorophenoxyacetic acid, 2,4,5-trichlorophenoxyacetic acid, 4-chlorophenoxyacetic acid, 2-(2,4-dichlorophenoxy)propionic acid, and 2-(2,4,5-trichlorophenoxy)propionic acid, were studied and determinedby ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). MIL-101(Cr)-NH2 was characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, and surface area measurement. Several extraction parameters were optimized, and under the most favorable conditions, the SL-DSPE-UHPLC-MS/MS method achieved enrichment factors between 25 and 66. Low limits of detection (2.66-19.7ng·L-1) and wide dynamic working ranges with good linearity (r2 ≥ 0.991) were attained for all analytes. The method was repeatable, with intra- and inter-day relative standard deviations (RSDs) below4.5 and 7.6%, respectively, for three replicate determinations. The application of SL-DSPE-UHPLC-MS/MS to paddy field waters gave satisfactory relative recoveries ranging between 80.2 and 108%, with RSDs better8.4%. Several of the CPAs were detected in these samples. Graphical abstract Schematic of the solvent-loaded dispersive solid-phase extraction procedure. By directly loading dichloromethane into the pores of MIL-101(Cr)-NH2, this method improves the extraction capability of the sorbent through the combination of solvent- and sorbent-based microextraction.

Microextraction and its application for petroleum and crude oil samples

Petroleum is an extremely heterogeneous material. It consists of a wide range of aliphatic, aromatic, and compounds containing heteroatoms such as metals, sulfur, and nitrogen. The American Society for Testing and Materials (ASTM) methods are used globally as accepted analytical methods for petroleum, petrochemicals, and fuels. A major drawback of ASTM methods is that they require multistep sample preparation that consumes substantial volumes of samples. Thus, the challenge in the petrochemical analysis is to develop rapid and simpler sample preparation procedures that can be automated. An assessment based on the current literature, specifically on the sample preparation of petroleum samples, leads to the authors' conclusion that microextraction provides an excellent complement to current methods. In this review, solvent and sorbent-based microextraction techniques in the context of the consideration of petroleum and crude oil, and samples related to the petrochemical industry, are discussed.

Modern microextraction techniques for natural products.

Natural product analysis has gained wide attention in recent years, especially for herbal medicines, which contain complex ingredients and play a significant clinical role in the therapy of numerous diseases. The constituents of natural products are usually found at low concentrations, and the matrices are complex. Thus, the extraction of target compounds from natural products before analysis by analytical instruments is very significant for human health and its wide application. The commonly used traditional extraction methods are time-consuming, using large amounts of sample and organic solvents, as well as expensive and inefficient. Recently, microextraction techniques have been used for natural product extraction to overcome the disadvantages of conventional extraction methods. In this paper, the successful applications of and recent developments in microextraction techniques including solvent-based and sorbent-based microextraction methods, in natural product analysis in recent years, especially in the last 5 years, are reviewed for the first time. Their features, advantages, disadvantages, and future development trends are also discussed.

Evolution and current advances in sorbent-based microextraction configurations

This review overviews the main developments achieved in analytical sample preparation regarding the use of solid sorbents as extractants in different sorbent-based miniaturized, micro-scale and microextraction methods. Two main groups are proposed for the classification of the current approaches, based on their operational mode: micro-solid-phase extraction (µ-SPE) and solid-phase microextraction (SPME), while describing their respective main sub-modes: static- and dispersive-µ-SPE, and SPME with fibers and in tube SPME. Furthermore, other important sorbent-based microscale approaches (e.g., stir bar sorptive extraction, stir cake sorptive extraction, stir bar sorptive-dispersive microextraction, and thin film microextraction, among others) are also considered.

New Advanced Materials and Sorbent-Based Microextraction Techniques as Strategies in Sample Preparation to Improve the Determination of Natural Toxins in Food Samples.

Natural toxins are chemical substances that are not toxic to the organisms that produce them, but which can be a potential risk to human health when ingested through food. Thus, it is of high interest to develop advanced analytical methodologies to control the occurrence of these compounds in food products. However, the analysis of food samples is a challenging task because of the high complexity of these matrices, which hinders the extraction and detection of the analytes. Therefore, sample preparation is a crucial step in food analysis to achieve adequate isolation and/or preconcentration of analytes and provide suitable clean-up of matrix interferences prior to instrumental analysis. Current trends in sample preparation involve moving towards “greener” approaches by scaling down analytical operations, miniaturizing the instruments and integrating new advanced materials as sorbents. The combination of these new materials with sorbent-based microextraction technologies enables the development of high-throughput sample preparation methods, which improve conventional extraction and clean-up procedures. This review gives an overview of the most relevant analytical strategies employed for sorbent-based microextraction of natural toxins of exogenous origin from food, as well as the improvements achieved in food sample preparation by the integration of new advanced materials as sorbents in these microextraction techniques, giving some relevant examples from the last ten years. Challenges and expected future trends are also discussed.

An improved fabric phase sorptive extraction method for the determination of five selected antidepressant drug residues in human blood serum prior to high performance liquid chromatography with diode array detection

Fabric phase sorptive extraction (FPSE), a recently introduced sorbent-based microextraction technique, was applied for the first time in order to achieve a simple and rapid simultaneous extraction of five common antidepressant drug residues (venlafaxine, paroxetine, fluoxetine, amitriptyline and clomipramine) from human blood serum. Elimination of protein precipitation step and minimized solvent consumption led to a sample preparation workflow compliant with the principles of green analytical chemistry (GAC). FPSE utilizes permeable and flexible fabric substrate chemically coated with a sol-gel organic-inorganic hybrid sorbent as the extraction device. Among all the membrane examined, sol-gel polycaprolactone-dimethylsiloxane-polycaprolactone coated polyester substrate presented optimum extraction efficiency and was found to be reusable for at least 30 times. The selected drugs were analyzed and detected by reversed phase high performance liquid chromatography method using gradient elution and a diode array detector operated at 235 nm. Limit of detection was found 0.15 ng μL−1, while good absolute recoveries (9.4–88.1%) and low relative standard deviations (≤9.2% and ≤ 11.0 for within-day and between-day precision, respectively) were obtained.

Fabric phase sorptive extraction for simultaneous observation of four penicillin antibiotics from human blood serum prior to high performance liquid chromatography and photo-diode array detection

Fabric phase sorptive extraction (FPSE), a current and up-to-date technique of solid sorbent-based microextraction, is regarded to be the basis of the development and advancement of an environmentally friendly, simple, sensitive, trustworthy, and fast analytical method by making use of high performance liquid chromatography and photo-diode array detection (HPLC-PDA) for the concurrent determination of four penicillin antibiotics residues (benzylpenicillin, cloxacillin, dicloxacillin and oxacillin) in human blood serum. By means of FPSE, the sophisticated material properties of sol-gel derived extraction and microextraction sorbents and the rich surface chemistry of an inherent porous and hydrophilic cellulose fabric substrate are successfully combined, leading to a flexible microextraction device which is characterized by high efficiency in extracting target analytes directly from complex sample matrices. Solvent evaporation and reconstitution steps, which are considered to be rather time-consuming, were eradicated successfully from the sample preparation workflow, organic solvent consumption was brought to a minimum while protein precipitation was assessed as impractical. Thus, FPSE complies with all green analytical chemistry (GAC) criteria. The microextraction device is characterized by a very high chemical and solvent stability owing to the strong chemical bonds formed between the sol–gel sorbent and the substrate. Thus, any organic solvent/solvent mixture can serve as the eluent/back-extraction solvent. Herein, sol-gel poly(tetrahydrofuran) coated FPSE membrane provided optimum extraction sensitivity for the selected penicillin antibiotics, which were analyzed using an RP-HPLC method, validated in terms of sensitivity, linearity, accuracy, precision, and selectivity. For all four penicillin antibiotics, the limit of detection and the limit of quantitation were 0.15 ng/μL and 0.5 ng/μL, respectively.

Fabric phase sorptive extraction of selected penicillin antibiotic residues from intact milk followed by high performance liquid chromatography with diode array detection.

Fabric phase sorptive extraction (FPSE), a novel sorbent-based microextraction method, was evaluated as a simple and rapid strategy for the extraction of four penicillin antibiotic residues (benzylpenicillin, cloxacillin, dicloxacillin and oxacillin) from cows' milk, without prior protein precipitation. Time-consuming solvent evaporation and reconstitution steps were eliminated successfully from the sample preparation workflow. FPSE utilizes a flexible fabric substrate, chemically coated with sol-gel derived, highly efficient, organic-inorganic hybrid sorbent as the extraction medium. Herein short-chain poly(ethylene glycol) provided optimum extraction sensitivity for the selected penicillins, which were analysed using an RP-HPLC method, validated according to the European Decision 657/2002/EC. The limit of quantitation was 10μg/kg for benzylpenicillin, 20μg/kg for cloxacillin, 25μg/kg dicloxacillin and 30μg/kg oxacillin. These are a similar order of magnitude with those reported in the literature and (with the exception of benzylpenicillin) are less than the maximum residue limits (MRL) set by European legislation.