Magnetic solid phase extraction for determination of drugs in biological matrices

Design, spectroscopic analysis, DFT calculations, adsorption evaluation, molecular docking, comprehensive in silico and in vitro bioactivity studies of thiocarbohydrazide grafted dialdehyde cellulose nanobiosorbent

Heavy metals have attracted considerable attention lately because of their widespread occurrence in aquatic environments and potential biological toxicity to animals and human. The current investigation focused on synthesizing the DAC@TCH nanobiosorbent by coupling dialdehyde cellulose with thiocarbohydrazide ligand. Subsequent characterization of DAC@TCH was carried out utilizing various analytical methods such as elemental analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR), and thermogravimetric analysis (TGA and DTA). DFT calculations were utilized to verify the molecular structure, analysis of frontier molecular orbitals (FMOs), molecular electrostatic potential (MEP) and reactivity descriptor for all phases. In vitro experiments were conducted to evaluate the biological properties of the DAC@TCH nanobiosorbent. These findings revealed that the synthesized DAC@TCH nanobiosorbent has been observed to show effective antibacterial IZD value against E. Coli (28 mm) which is superior to the efficacy of standard drug amoxicillin used (5 mm). Furthermore, in silico antibacterial activities (molecular docking) of the DAC@TCH have indicated this to exhibit excellent efficacy with docking score of (-7.4237 kcal/mol) and (-7.1325 kcal/mol) for S. aureus and, E. coli, respectively. Meanwhile the binding energies (best docking scores) in kcal/mol for Amoxicillin are (-5.8090) and (-6.7442) for S. aureus and, E. coli, respectively. Drug-likeness rules like Lipinski's, Veber's and Egan's were considered for a more comprehensive evaluation. The prepared DAC@TCH nanobiosorbent was investigated for its potential to adsorb metal ions (Ag+, Hg2+, and Cu2+) from diverse water samples. Optimal conditions including pH, temperature, DAC@TCH dosage, oscillation time, initial metal ion concentration, and interference from other ions were explored. The adsorption of Hg2+, Cu2+, and Ag+ ions by DAC@TCH followed pseudo-second-order kinetics and Langmuir isothermal model, achieving maximum adsorption capacities of 196 mg/g for Ag+, 190 mg/g for Hg2+, and 73 mg/g for Cu2+. The adsorption process was determined to be exothermic and spontaneous across varying temperatures. Additionally, over 95% of adsorbed metal ions were effectively desorbed using thiourea (5%) and 0.3 M HNO3 elution mixture. DAC@TCH nanobiosorbent demonstrated excellent reusability, retaining its adsorption capacity through five cycles without degradation. The study highlights the potential of DAC@TCH for efficient recovery of heavy metals from different water sources, considering its application versatility, reusability, and minimal interference. Furthermore, the plausible mechanism of Ag+, Hg2+, and Cu2+ adsorption onto DAC@TCH bionanosorbent is elucidated.

A Review on the Applications of Quantum Dots in Sample Preparation

In recent years, despite significant advances in preconcentration and preparation techniques that have led to efficient recovery and accurate measurement of target compounds. There is still a need to develop adsorbents with unique and efficient features such as high pore volume and surface area, reactivity, easy synthesis, low toxicity, and compatibility with the environment, which increase the adsorption capacity and increase extraction efficiency. Semiconductor nanocrystals called quantum dots (QDs) with a size of less than 10 nm are three-dimensional nanoparticles with a spherical, rod, or disc structure that have significant potential in extraction as adsorbents due to their excellent properties such as low toxicity, reactivity, environmental friendliness, and hydrophilic and hydrophobic interactions. One of the most basic issues in the development of adsorbents is to increase the effective surface and, as a result, their extraction efficiency. QDs, having an effective surface much higher than conventional nanomaterials, are a suitable option for extracting target compounds in different environments. This work comprehensively reviews QD-based extraction methods and surface modification strategies of QDs based on functional groups, ligands, and materials from 2013 to 2024. In addition, the applications of QD-based composites for the extraction of organic and inorganic analytes (residues of drugs in human blood and plasma, toxins, pesticides, pollutants from chemical industries, heavy metals, etc.) in different matrices are investigated.

Melt-blown polypropylene nonwoven as an efficient and eco-economic sorbent for pipette tip micro-solid phase extraction for the determination of tyrosine kinase inhibitors

BACKGROUND

The detection of tyrosine kinase inhibitors (TKIs) in biological fluids is essential due to their critical role in cancer therapy and the variability in individual drug metabolism, which necessitates precise dosing. Traditional methods for analyzing TKIs in biological fluids, such as blood plasma, typically involve complex sample preparation techniques that can be resource-intensive, environmentally burdensome, and not sufficiently sensitive for low-concentration analytes. There is a pressing need for more efficient, economical, and environmentally friendly methods that can enhance sensitivity and throughput without compromising accuracy.

RESULTS

This study explores the use of melt-blown polypropylene nonwoven (MBPP), commonly found in face masks, as a novel sorbent for pipette-tip micro-solid phase extraction (PT-μSPE). MBPP demonstrated excellent hydrophobicity and significant mesoporous adsorption capacity. An extraction device was fashioned by inserting a segment of MBPP (15 mg) into a 200 μL disposable plastic pipette tip, which was then attached to a 2.5 mL disposable plastic syringe. The MBPP's fabric form removes the need for a frit, allowing the extraction process to be completed in just 3 min through simple plunger manipulation. The method achieved extraction recoveries ranging from 60.5 % to nearly 100 %. Subsequent method validation using liquid chromatography-tandem mass spectrometry (LC-MS/MS) showed satisfactory linearity (coefficient of determination R2 > 0.993), accuracy (relative recoveries: 86.3%-114.8 %), and precision (relative standard deviation: 3.4%-11.3 %), with detection limits between 0.022 and 0.135 ng mL-1.

SIGNIFICANCE

The introduction of MBPP for PT-μSPE represents a significant advancement in the bioanalytical detection of TKIs, offering a highly efficient, cost-effective, and environmentally sustainable method. It compares favorably with existing techniques, offering advantages in terms of cost, environmental impact, and ease of use. This approach has the potential to be widely adopted for routine monitoring of TKIs in clinical settings.

Fast and efficient extraction and determination of nonsteroidal anti-inflammatory drugs using poly(8-hydroxyquinoline)-coated magnetic graphene oxide nanocomposite prior to capillary electrophoresis analysis in wastewater, breast milk, and urine samples

In this study, magnetic graphene oxide coated with poly(8-hydroxyquinoline) was successfully synthesized, characterized, and utilized as a novel sorbent for the ultrasonic-assisted dispersive magnetic solid-phase extraction of naproxen and ibuprofen. These analytes served as representative analytes for two nonsteroidal anti-inflammatory drugs in various real samples. Characterization techniques, such as IR, X-ray powder diffraction, field emission scanning electron microscopy, energy-dispersive X-ray-mapping, and Brunauer-Emmett-Teller (BET), were used to confirm the correctness synthesis and preparation of the nanocomposites. Effective parameters on the extraction efficiency were investigated to maximize the analytical performance of the developed method. The dynamic range (1-1000 µg L-1), coefficients of determination (R2 ≥ 0.997), the limits of detection (0.3-1.0 µg L-1), and limit of quantification (1.0-3.0 µg L-1), intra-day and inter-day precisions (3.5%-7.2%) were achieved. The method validation results showed extraction recovery ranging from 80.4% to 96.0% and preconcentration factors ranging from 137 to 140.

Advances in magnetic analytical extraction techniques for detecting antibiotic residues in edible samples

The widespread use of antibiotics in agricultural and animal husbandry to treat bacterial illnesses has resulted in a rise in antibiotic-resistant bacteria. These bacteria can grow when antibiotic residues are present in food items, especially in edible animal products. As a result, it is crucial to monitor and regulate the amounts of antibiotics in food. Magnetic analytical extractions (MAEs) have emerged as a potential approach for extracting antibiotic residues from food using magnetic nanoparticles (MNPs). Recent improvements in MAEs have resulted in the emergence of novel MNPs with better selectivity and sensitivity for the extraction of antibiotic residues from food samples. Consequently, this review paper addresses current developments in MAE for extracting antibiotic residues from edible samples. It also provides a critical analysis of contemporary MAE practices. The current issues and potential future developments in this field are also discussed, thereby providing a framework for future study paths.

Greener and whiter analytical method development and validation for determining the presence of zolpidem tartrate infused in apple juice using RP-HPLC via magnetic solid-phase extraction followed by LC-MS confirmatory analysis

The research work entails a newly developed RP-HPLC method, aimed at analyzing the modern date rape drug, zolpidem tartrate (ZT), infused in apple juice matrix. The work relies on dispersive solid-phase extraction (DSPE) with polyethylene imine (PEI)-coated magnetic nanoparticles to preconcentrate zolpidem from the matrix, in the presence of trifluoroacetic acid (TFA) for matrix isolation, for the first time. The optimized conditions emphasize the use of an environmentally preferable mobile phase [methanol: 0.5% acetic acid (60 : 40% v/v; pH 2.50)] at a 1 ml min-1 flow rate, employed with a Platisil Octa-Decyl Silane (ODS) column (250 × 4.6 mm; 5 μm). Further, the validated results were confirmed to be within the ICH guidelines, marking the method demonstrated to be linear (R 2 = 0.9988; 0.9957), robust (% RSD below 1), sensitive (LOD = 1.8 μg ml; LOQ = 6 μg ml-1), precise and accurate (% recovery = 92-120%). Following the same conditions, a confirmatory analysis of zolpidem was accomplished using LC-MS, verifying the method's suitability notably, with good peak resolution, less matrix interference and a confirmation of the presence of zolpidem using mass spectrometry. The recycling ability of the PEI@SiO2@Fe3O4 nanoparticles was also assessed. To determine the sustainability of the proposed work, a greener and whiter assessment has been carried out in a comparative mode with previous similar works. For green tools, the recently developed AGREE software was utilized for assessing the method's greeness and it demonstrated a good green score of 0.68, supported by method assessment using ComplexGAPI software. For the assessment of the method's blue principles, the latest software utilizing the blue applicability grade index (BAGI) was applied, resulting in a decent score of 62.5. To consider sustainability, the RGB methodical software in its latest version the RGBfast model, was incorporated in the study for furnishing a balance of the three different major principles (Red-Green-Blue) and for assessing a check on sustainability of the current method compared to similar previously established proposed works.

Magnetic materials as adsorbents for the pre-concentration and separation of active ingredients from herbal medicine

Herbal medicine (HM) is crucial in disease management and contains complex compounds with few active pharmacological ingredients, presenting challenges in quality control of raw materials and formulations. Effective separation, identification, and analysis of active components are vital for HM efficacy. Traditional methods like liquid-liquid extraction and solid-phase extraction are time-consuming and environmentally concerning, with limitations such as sorbent issues, pressure, and clogging. Magnetic solid-phase extraction uses magnetic sorbents for targeted analyte separation and enrichment, offering rapid, pressure-free separation. However, inorganic magnetic particles' aggregation and oxidation, as well as lack of selectivity, have led to the use of various coatings and modifications to enhance specificity and selectivity for complex herbal samples. This review delves into magnetic composites in HM pretreatment, specifically focusing on encapsulated or modified magnetic nanoparticles and materials like silica, ionic liquids, graphene family derivatives, carbon nanotubes, metal-organic frameworks, covalent organic frameworks, and molecularly imprinted polymers.

Unravelling the potential of magnetic nanoparticles: a comprehensive review of design and applications in analytical chemistry

The study of nanoparticles has emerged as a prominent research field, offering a wide range of applications across various disciplines. With their unique physical and chemical properties within the size range of 1-100 nm, nanoparticles have garnered significant attention. Among them, magnetic nanoparticles (MNPs) exemplify promising super-magnetic characteristics, especially in the 10-20 nm size range, making them ideal for swift responses to applied magnetic fields. In this comprehensive review, we focus on MNPs suitable for analytical purposes. We investigate and classify them based on their analytical applications, synthesis routes, and overall utility, providing a detailed literature summary. By exploring a diverse range of MNPs, this review offers valuable insights into their potential application in various analytical scenarios.

Fabrication and characterization of magnetic mesoporous nanoparticles for efficient determination and magnetic separation of sulfonamides in food samples

A magnetic, mesoporous core/shell structured Fe3O4@SiO2@mSiO2 nanocomposite was synthesized and employed as a magnetic solid phase extraction (MSPE) sorbent for the determination of trace sulfonamides (SAs) in food samples. The synthesized nanocomposite was characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis, X-ray diffraction, N2 sorption analysis and vibrating sample magnetometry. The results showed that Fe3O4@SiO2@mSiO2 possessed a mesoporous structure with a large surface area. Batch experiments were carried out to investigate the adsorption ability for SAs. Fe3O4@SiO2@mSiO2 showed fast kinetics and high adsorption capacity, and the pseudo-second-order model and Langmuir adsorption isotherm are well fitted with the experimental data, indicating that chemical adsorption might be the rate-limiting step. Moreover, the high adsorption capacity can be maintained for at least 8 runs, indicating excellent stability and reusability. The proposed method exhibited good linearity in the range of 0.2-500 μg L-1, the R2 values of all the analytes were greater than 0.99 and the LODs were all lower than 0.2 μg L-1. Furthermore, real food samples were successfully analyzed with Fe3O4@SiO2@mSiO2 and high recoveries varying from 89.7% and 110.6% were obtained with low relative standard deviations ranging from 1.78% to 6.91%. The Fe3O4@SiO2@mSiO2 magnetic nanocomposite is a promising sorbent for the efficient extraction of SAs from complex food samples.

Functionalized magnetic nanomaterials as recyclable adsorbents for efficient flavonoid enrichment in Scutellaria Radix

A magnetic composite (Fe3O4@SiO2@PNIPAM-co-NHMA) with high adsorption capacity and recoverability was developed for the enrichment and determination of flavonoids in Scutellaria Radix (SR). A magnetic solid-phase extraction (MSPE) technique using Fe3O4@SiO2@PNIPAM-co-NHMA absorbent in combination with high-performance liquid chromatography (HPLC) was developed for selectively enrichment and determination of the biologically active flavonoids in the aqueous extract of SR, including baicalein, baicalin, wogonoside and wogonin. Under the optimized experimental conditions, the magnetic adsorbent could adsorb up to 77.0 ± 0.98 % - 98.15 ± 0.15 % of four representative flavonoids from SR, with elution rates varying from 55.10 ± 0.25 % to 91.94 ± 1.85 %. The limits of detection (LOD) and limits of quantitation (LOQ) were 0.01-0.35 μg/mL and 0.03-0.98 μg/mL, respectively. In addition, it remained effective after six replicates, demonstrating its potential as a recoverable adsorbent for enriching flavonoids in traditional Chinese medicine.

Enrichment of Phosphopeptides Based on Zirconium Phthalocyanine-Modified Magnetic Nanoparticles

Highly selective extraction of phosphopeptides is necessary before mass spectrometry (MS) analysis. Herein, zirconium phthalocyanine-modified magnetic nanoparticles were prepared through a simple method. The Fe-O groups on Fe3O4 and the zirconium ions on phthalocyanine had a strong affinity for phosphopeptides based on immobilized metal ion affinity chromatography (IMAC). The enrichment platform exhibited low detection limit (0.01 fmol), high selectivity (α-/β-casein/bovine serum albumin, 1/1/5000), good reusability (10 circles), and recovery (91.1 ± 1.1%) toward phosphopeptides. Nonfat milk, human serum, saliva, and A549 cell lysate were employed as actual samples to assess the applicability of the enrichment protocol. Metallo-phthalocyanine will be a competitive compound for designing highly efficient adsorbents and offers a new approach to phosphopeptide analysis.

A guide to the use of bioassays in exploration of natural resources

Bioassays are the main tool to decipher bioactivities from natural resources thus their selection and quality are critical for optimal bioprospecting. They are used both in the early stages of compounds isolation/purification/identification, and in later stages to evaluate their safety and efficacy. In this review, we provide a comprehensive overview of the most common bioassays used in the discovery and development of new bioactive compounds with a focus on marine bioresources. We present a comprehensive list of practical considerations for selecting appropriate bioassays and discuss in detail the bioassays typically used to explore antimicrobial, antibiofilm, cytotoxic, antiviral, antioxidant, and anti-ageing potential. The concept of quality control and bioassay validation are introduced, followed by safety considerations, which are critical to advancing bioactive compounds to a higher stage of development. We conclude by providing an application-oriented view focused on the development of pharmaceuticals, food supplements, and cosmetics, the industrial pipelines where currently known marine natural products hold most potential. We highlight the importance of gaining reliable bioassay results, as these serve as a starting point for application-based development and further testing, as well as for consideration by regulatory authorities.

Self-assembled Fe3O4-NH2 @g-C3N4 composite for magnetic solid-phase extraction of benzophenones in sea water and lake water coupled with LC-MS/MS determination

Magnetic solid-phase extraction (MSPE) was developed based on a well-designed Fe3O4-NH2 @g-C3N4 nanocomposite as sorbent for a mixture of six benzophenones (BPs) in environmental water samples. The composite fabricated via in-situ self-assembled g-C3N4 shell with homogeneous polymerization of cyanuric chloride and cyanuric acid on Fe3O4-NH2 core. While high adsorption capacity was derived from g-C3N4 via hydrophobic, π-π and hydrogen bonding interactions to the targets, the fast magnetic separation was realized with Fe3O4 core for less solvent consumption. In combination with LC-MS/MS, the Fe3O4-NH2 @g-C3N4 sorbent minimized the interfering components, reduced the matrix effects, and provided the enrichment factors of 121-150 for six BPs with relative standard deviations ≤ 9.7% even after 20 times extraction-desorption cycles. The present method gave the detection limits of 0.3-2.5 ng/L for six BPs with the linear ranges of 1.0-2000 ng/L, and the recoveries of 84.6%-104% in sea water and 86.2%-107% in lake water samples. Thus, the Fe3O4-NH2 @g-C3N4-based MSPE coupled with LC-MS/MS method provided a convenient, efficient, and reliable alternative to monitor trace BPs in environmental water samples.

Developing magnetic functionalized dendritic fibrous mesoporous silica as advanced adsorbent for quaternary ammonium alkaloids

A novel π-conjugated polymer-modified magnetic dendritic fibrous mesoporous silica adsorbent (MB@KCC-1@π-CP) is reported for the accurate determination of quaternary ammonium alkaloids (QAAs) in complex body fluid matrices. It is demonstrated that the magnetic dendritic fibrous mesoporous silica (MB@KCC-1) is an excellent carrier combining magnetism, high specific surface area, unique hierarchical pore structure, and fast mass transfer rate. The π-conjugated polymer (π-CP) can efficiently retain QAAs (berberine, coptisine, palmatine, jatrorrhizine) by multiple interactions. In addition, the adsorption kinetics and adsorption mechanism were also studied and discussed. Under optimized extraction conditions, MB@KCC-1@π-CP-based magnetic solid-phase extraction (MSPE) and high-performance liquid chromatography (HPLC) method affords a wide linear range (0.5-20000 ng mL-1), low limits of detection (0.2-2 ng mL-1), and satisfactory relative standard deviations (RSD) of inter-day (< 2.4%) and intra-day (< 3.1%) for QAAs. Trace QAAs in complex human blood plasma samples were successfully detected by the established method.

Magnetic solid-phase extraction of polycyclic aromatic hydrocarbons from water samples using magnetic carbon nanofiber/MIL-101(Cr) nanocomposites

In this study, magnetic carbon nanofibers (Fe3O4@CNF) were modified with MIL-101(Cr) (Fe3O4@CNF@MIL-101) and used as sorbents for magnetic solid-phase extraction (MSPE) to extract polycyclic aromatic hydrocarbons (PAHs) from real water samples. Gas chromatography coupled with a flame ionization detector (GC-FID) was used for the determination of the PAHs. The effect of experimental variables on the extraction efficiency of PAHs was investigated and optimized. These variables include the quantity of sorbent, the kind and volume of the elution solvent, the duration of extraction and desorption, and the salt concentration. The linear range was found to be 0.01 to 200 ng mL-1 with correlation coefficients ranging from 0.9906 to 0.9931 after the effective extraction parameters were optimized. Its detection limits (LOD) were also calculated to be between 0.003 and 0.005 ng mL-1 (S/N = 3). The method's repeatability was tested at three different concentration levels (0.1, 1, and 10 ng mL-1), and relative standard deviations (RSDs%) were obtained in the range of 2.3 to 5.0%. Finally, using the MSPE-GC-FID method, PAHs were extracted from tap water, wastewater, seawater, and spring water samples. The relative recoveries were in the range of 95.7 to 99.8%.

Microextraction by packed sorbent of some β-blocker drugs with chitosan@mof-199 bio-composite in human saliva, plasma, and urine samples

The current study introduces microextraction by packed sorbent (MEPS) to extract three beta-blocker drugs (propranolol, atenolol, and betaxolol) from biological samples. The separation and detection of the drugs were performed by high performance liquid chromatography followed by UV detection. A green approach was applied for synthesizing chitosan@MOF-199 bio-composite, which was packed into the initial part of a metal spinal (22 gage). The effective parameters on the adsorption and desorption efficiencies, including sample solution pH, eluent flow rate, cycle numbers, type and volume of eluent solvent were evaluated and optimized. Under optimal conditions linear ranges (LRs = 5-600 µg L-1), limits of detection (LODs = 1.5-4.5 µg L-1), and relative standard deviations (RSDs% = 4.7 -5.3% with three replicates and concentration of 100 µg L-1) were obtained. Relative recoveries (RR%) for plasma (77-99%), saliva (81-108%), and urine (80-112%) samples were obtained. In this study, the drug release profile of propranolol in urine was evaluated. The results showed that the highest amount of propranolol is released 4 h after taking the drug. Based on the obtained results, this is an effective, fast, sensitive, reproducible, green, and user-friendly method for beta-blocker drug extraction in biological samples.

Ultra-High Adsorption Capacity of Core-Shell-Derived Magnetic Zeolite Imidazolate Framework-67 as Adsorbent for Selective Extraction of Theophylline

A core-shell-derived structural magnetic zeolite imidazolate framework-67 (Fe₃O₄-COOH@ZIF-67) nanocomposite was fabricated through a single-step coating of zeolite imidazolate framework-67 on glutaric anhydride-functionalized Fe₃O₄ nanosphere for the magnetic solid-phase extraction (MSPE) of theophylline (TP). The Fe₃O₄-COOH@ZIF-67 nanocomposite was characterized through scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectrometry, Fourier transform infrared spectroscopy, Zeta potential analysis, X-ray diffraction, Brunauer-Emmett-Teller, and vibrating sample magnetometer. The material has a high specific surface area and good magnetism, which maintains the regular dodecahedron structure of ZIF-67 without being destroyed by the addition of Fe₃O₄-COOH nanospheres. The Fe₃O₄-COOH@ZIF-67 can rapidly adsorb TP mainly through the strong coordination interaction between undercoordinated Co²⁺ on ZIF-67 and -NH from imidazole of TP. The adsorption and desorption conditions, such as the amount of adsorbent, adsorption time, pH value, and elution solvent, were optimized. The kinetics of TP adsorption on Fe₃O₄-COOH@ZIF-67 was found to follow pseudo-second-order kinetics. The Langmuir model fits the adsorption data well and the maximum adsorption capacity is 1764 mg/g. Finally, the developed MSPE-HPLC method was applied in the enrichment and analysis of TP in four tea samples and rabbit plasma. TP was not detected in oolong tea and rabbit plasma, and its contents in jasmine tea, black tea, and green tea are 5.80, 4.31, and 1.53 μg/g, respectively. The recoveries of spiked samples are between 74.41% and 86.07% with RSD in the range of 0.81-3.83%. The adsorption performance of Fe₃O₄-COOH@ZIF-67 nanocomposite was nearly unchanged after being stored at room temperature for at least 80 days and two consecutive adsorption-desorption cycles. The results demonstrate that Fe₃O₄-COOH@ZIF-67 nanocomposite is a promising magnetic adsorbent for the preconcentration of TP in complex samples.

Analytical approaches for screening of per- and poly fluoroalkyl substances in food items: A review of recent advances and improvements

Per and polyfluoroalkyl substances (PFAS) are a group of man-made chemicals characterized by their ubiquitous nature in all environmental compartments which makes them of increasing concern due to their persistence, bioaccumulation, and toxicity (PBT). Several instrumental methodologies and separation techniques have been identified in the literature for the detection and quantification of PFAS in environmental samples. In this review, we have identified and compared common separation techniques adopted for the extraction of PFAS in food items, and analytical methodologies for identification and quantification of PFAS in food items of plant and animal origin, highlighting recent advances in tandem techniques for the high selectivity and separation of PFAS related compounds as well as knowledge gaps and research needs on current analytical methodologies.

Use of newly synthetized magnetic Fe3O4 nanoparticles modified with hexadecyl trimethyl ammonium bromide for the sensitive analysis of antidepressant drugs, duloxetine and vilazodone in wastewater and urine samples

A new enrichment and determination method involving HPLC-DAD analysis following magnetic solid-phase extraction (MSPE) was developed to detect trace amounts of two antidepressant drugs, namely, duloxetine (DUL) and vilazodone (VIL). In this study, a solid-phase sorbent was newly synthesized for use in the MSPE and its characterization was carried out by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy and X-ray diffraction (XRD) techniques. In this proposed method, DUL and VIL molecules were enriched using newly synthesized magnetic-based nanoparticles in the presence of pH 10.0 buffer and desorbed with acetonitrile to a smaller volume prior to chromatographic determinations. After experimental variables were optimized, the VIL and DUL molecules were analyzed at wavelengths of 228 nm for DUL and 238 nm for VIL with isocratic elution of methanol, trifluoroacetic acid (TFA) (0.1%), and acetonitrile (10 : 60 : 30). The detection limits obtained under optimized conditions were 1.48 ng mL^-1 and 1.43 ng mL^-1, respectively. The %RSD values were found to be lower than 3.50% with model solutions containing 100 ng mL^-1 (N:5). Finally, the developed method was successfully applied to wastewater samples and simulated urine samples, and quantitative results were obtained in the recovery experiments.

Magnetic tubular nickel@silica-graphene nanocomposites with high preconcentration capacity for organothiophosphate pesticide removal in environmental water: Fabrication, magnetic solid-phase extraction, and trace detection

Organothiophosphate pesticides (OPPs) are the most common water contaminants, significantly endangering human health and bringing serious public safety issues. Thus, developing effective technologies for the removal or trace detection of OPPs from water is urgent. Herein, a novel graphene-based silica-coated core-shell tubular magnetic nanocomposite (Ni@SiO₂-G) was fabricated for the first time and used for the efficient magnetic solid-phase extraction (MSPE) of the OPPs chlorpyrifos, diazinon, and fenitrothion from environmental water. The experimental factors affecting extraction efficiency such as adsorbent dosage, extraction time, desorption solvent, desorption mode, desorption time, and adsorbent type were evaluated. The synthesized Ni@SiO₂-G nanocomposites showed a higher preconcentration capacity than the Ni nanotubes, Ni@SiO₂ nanotubes, and graphene. Under the optimized conditions, 5 mg of tubular nano-adsorbent displayed good linearity within the range of 0.1-1 μg·mL^-1, low limits of detection (0.04-0.25 pg·mL^-1), low limits of quantification (0.132-0.834 pg·mL^-1), good reusability (n = 5; relative standard deviations between 1.46% and 9.65%), low dosage (5 mg), and low real detection concentration (< 3.0 ng·mL^-1). Moreover, the possible interaction mechanism was investigated by density functional theory calculation. Results showed that Ni@SiO₂-G was a potential magnetic material for the preconcentration and extraction of formed OPPs at ultra-trace levels from environmental water.

A new approach of magnetic field application in miniaturized pipette-tip extraction for trace analysis of four synthetic hormones in breast milk samples

Herein, a novel homemade electrical device was designed, including two pieces of external neodymium magnets, providing a reciprocating magnetic field to introduce a magnetic-assisted dispersive pipette-tip micro solid-phase extraction. To evaluate the performance efficiency of the proposed method, a novel magnetic calcined GO/SiO₂@Co-Fe nanocube sorbent was synthesized, filled into the pipette-tip, exposed to the reciprocating magnetic field, and applied for the preconcentration of some hormone therapy drugs in human biological matrices. The effective adsorption and desorption parameters were optimized using a rotatable central composite design and one-variable-at-a-time approaches. Under the optimized conditions, the target analytes' detection limits were found to be below 0.02 ng mL^-1. Moreover, the calibration curves were linear in the range of 0.03-500.00 ng mL^-1 (R² > 0.9966), with RSDs% less than 7.8 %. Eventually, the established method was applied to extract the analytes from breast milk samples, followed by LC-ESI-MS/MS analysis.

Application of magnetic solid-phase extraction for sensitive determination of anticancer drugs in urine by means of diamino benzidine tetrachlorohydrate modified magnetic nanoparticles

BACKGROUND

The analysis of drug active molecules and residues in the treatment of cancer is important for the sustainability of human life and therapeutic effects. For this purpose, a new magnetic sorbent was developed to use in solid phase extraction prior to conventional high-performance liquid chromatography (HPLC) analysis of Paclitaxel (PAC) and Gemcitabine (GEM) molecules.

METHODS

In this study, a separation and pre-concentration approach based on magnetic solid phase extraction (MSPE) was proposed for PAC and GEM by means of using a newly synthesized magnetic sorbent. After the MSPE procedure, an HPLC system with a diode array detector (DAD) was used to analyze trace amounts of PAC and GEM anticarcinogenic drugs in urine samples. Surface modification of magnetic Fe₃O₄ nanoparticles was carried out by diaminobenzidinetetrachloro hydrate (DABTC) for the first time and a useful sorbent was obtained for MSPE experiments.

RESULTS

In the proposed method, PAC and GEM molecules were retained on the c in the presence of a pH 5.0 medium and desorbed to 300 μL of acetonitrile: methyl alcohol (1:1) eluent phase before HPLC-DAD analysis. Under the optimized conditions, the limit of detection (LOD) values for PAC and GEM were 1.38 and 1.44 ng mL^-1 while the enhancement factor for PAC and GEM were 139.5 and 145.3, respectively. The relative standard deviations (RSD %) for PAC and GEM were below 3.50% in inter-day repeated experiments by means of model solutions containing 100 ng mL^-1 drug active ingredients.

CONCLUSIONS

Synthesis and characterization of DABTC-Fe₃O₄ nanoparticles were performed using suitable methodologies. Optimization of MSPE was done step by step. And finally, the developed method was successfully applied to urine samples with quantitative recoveries in the range of 99.0% and 105.0%.

Analytical perspective and environmental remediation potentials of magnetic composite nanosorbents

The synthesis and application of magnetic nanosorbents to remove emerging pollutants have been considered the best environmental remediation and sustainability option. Incorporating magnetism shortens the treatment time and allows the sorbent to be recovered quickly using external magnetic with many cycles. The implementation of magnetic solid-phase extraction (MSPE) using magnetic materials of different shapes, sizes, and surface morphology can be a valuable tool in applying materials to prepare analytical samples. In MSPE applications, materials with strong magnetic domain can be used as precursors for constructing magnetic composite as a promising sorbent. This article focuses on the most recent and exceptional applications of magnetic adsorbents for preconcentration and removal purposes. Magnetic adsorbents, such as nanoparticles (NPs), foam, sponges, nanocomposites, hydrogels, and beads with multifunctional attributes have been comprehensively studied in terms of preparation procedures, limitations, advantages, and interactions between pollutants and magnetic composites. The role of magnetic sorbents in sample preparation methods, such as simple solid-phase extraction and microextraction, as well as sorptive extraction using a stir bar, was also examined. The use of magnetic adsorbents with analytical techniques, such as solid-phase extraction and solid-phase microextraction improves the method for preparing samples concerning the influential role of magnetic adsorbents. Towards the end, promising features and future outlook are also directed.

Determination of Local Anesthetic Drugs in Human Plasma Using Magnetic Solid-Phase Extraction Coupled with High-Performance Liquid Chromatography

In this work, magnetic tetraethylenepentamine (TEPA)-modified carboxyl-carbon nanotubes were synthesized, characterized, and used as adsorbents to conduct magnetic solid-phase extraction (MSPE) for the preconcentration of seven local anesthetic drugs (procaine, lidocaine, mepivacaine, oxybuprocaine, bupivacaine, tetracaine, and cinchocaine) from human plasma. The separation and determination of analytes were performed on high-performance liquid chromatography with UV detection. Several factors affected the extraction efficiency, such as the amount of adsorbents used, extraction time, sample pH, and optimization of elution conditions. Under optimal conditions, satisfactory linear relationships were obtained in the range of 0.02-5.00 mg/L, with the limits of detection (LOD) ranging from 0.003 mg/L to 0.008 mg/L. The recoveries of analytes for spiked human plasma were in the range of 82.0-108%. Moreover, the precision with intra-day and inter-day RSD values were obtained in the range of 1.5-7.7% and 1.5-8.3%. The results indicated that this method could determine the concentration of seven local anesthetic drugs in human plasma with high precision and repeatability and provide support for the clinical monitoring of the concentration of local anesthetic drugs in human plasma.

Potential of sodium dodecyl sulfate micellar solutions as eluents in magnetic dispersive micro-solid phase extraction with polydopamine-coated magnetite nanoparticles. Application to antidepressant drugs

In this paper, the potential of micellar solutions of the anionic surfactant sodium dodecyl sulfate (SDS) as eluents in dispersive micro-solid phase extraction (D-μSPE) using polydopamine-coated magnetite nanoparticles (Fe₃O₄@PDA NPs) for the extraction and preconcentration of seven basic drugs (bupropion, citalopram, fluoxetine, mianserin, nomifensine, trimipramine, and viloxazine) is explored for the first time (to the best to our knowledge) and compared with conventional hydro-organic eluents. The impact of the sample solution pH, Fe₃O₄@PDA NPs and PDA coating amounts and extraction time on the extraction efficiency (EE), as well as the composition of the eluent on the overall efficiency (OE) are studied. Under the selected experimental conditions (50 mg of Fe₃O₄@PDA NPs, 100 μL of 1 M NH₃, 5 min of extraction time and 0.15 M SDS at pH 2.6 as eluent), EE and OE values were higher than 90% for all compounds and for the most hydrophobic compounds (trimipramine, fluoxetine and mianserin), respectively. The results shown in this paper demonstrate the suitability of Fe₃O₄@PDA NPs as a sorbent for the extraction of antidepressants as well as the advantages of using SDS micellar solutions over classic hydro-organic eluents containing methanol, acetonitrile or tetrahydrofuran. Finally, the stability and reusability of the Fe₃O₄@PDA NPs is proven.

Green bioanalysis: an innovative and eco-friendly approach for analyzing drugs in biological matrices

Green bioanalytical techniques aim to reduce or eliminate the hazardous waste produced by bioanalytical technologies. A well-organized and practical approach towards bioanalytical method development has an enormous contribution to the green analysis. The selection of the appropriate sample extraction process, organic mobile phase components and separation technique makes the bioanalytical method green. UHPLC-MS is the best option, whereas supercritical fluid chromatography is one of the most effective green bioanalytical procedures. Nevertheless, there remains excellent scope for further research on green bioanalytical methods. This review details the various sample preparation techniques that follow green analytical chemistry principles. Furthermore, it presents green solvents as a replacement for conventional organic solvents and highlights the strategies to convert modern analytical techniques to green methods.

Simple Synthesis of Fe3O4@-Activated Carbon from Wastepaper for Dispersive Magnetic Solid-Phase Extraction of Non-Steroidal Anti-Inflammatory Drugs and Their UHPLC–PDA Determination in Human Plasma

In the present society, the recycling and reuse of valuable substances are of utmost importance for economic and environmental purposes. At the same time, there is a pressing need to develop new methods to protect the ecosystem from many human activities, including those that have contributed to an ever-increasing presence of pharmaceutical pollutants. In this study, a straightforward approach that applies a magnetic carbon composite for the effective removal of NSAIDs from biological fluids is reported. The composite was produced by recycling wasted handkerchiefs, to provide cellulose to the reactive system and then transformed into carbon via calcination at high temperature. The morphological and structural features of the prepared “Fe3O4@-activated carbon” samples were investigated via thermal analysis, X-ray diffraction, Raman spectroscopy, and scanning electron microscopy. Magnetic solid-state extraction was carried out to reveal the adsorption capabilities of the magnetic carbon composite and then combined with UHPLC–PDA for the determination and quantification of five NSAIDs (furprofen, indoprofen, ketoprofen, flurbiprofen, and indomethacin). The method developed herein proved to be fast and accurate. The adsorbent could be reused for up to 10 cycles, without any decrease in performance; thus, it contributes to an intelligent and sustainable economic strategy projected toward minimal waste generation.

Biocompatible magnetite nanoparticles coated with ionic liquid-based surfactantas a hydrophilic sorbent for dispersive solid phase microextraction of cephalosporins prior to their quantitation by HPTLC

Extraction of highly hydrophilic compounds from biological fluids including urine or plasma samples is a dilemma due to high hydrophilicity of the matrix itself. The main aim of the current work is to explore the competence of ionic liquid (IL)-based surfactant-coated mineral oxide nanoparticles (NPs) in dispersive solid-phase microextraction (d-SPME) of highly hydrophilic analytes taking cefoperazone (CPZ) as a model analyte for the study. The IL-based surfactant coated Fe₃O₄ NPs is utilized as an innovative adsorbent for the separation and pre-concentration of CPZ after intramuscular injection (I.M) in rabbits. The utilized magnetite NPs were synthesized via simple and reliable co-precipitation procedure, which doesn't require any air-free environment and depends on a single iron (III) salt. Characterization of the as-synthesized NPs was achieved by X-ray powder diffraction (XRD), Fourier transform infrared (FT-IR) and energy dispersive X-ray (EDX). Surface area measurements show that Fe₃O₄ NPs have large surface area of 75 m² g^-1. The developed approach utilizes the unique properties of the IL-based surfactant including multiple polar interaction types provided by the polar head in addition to merits of Fe₃O₄ nanoparticles, which include large adsorptive capacity and magnetic properties, to improve separation, save time, and achieve satisfactory recovery. Comprehensive study was developed for the factors, that affect the adsorption capacity such as pH, NPs amount, IL-based surfactant concentration, ionic strength, adsorption time, and desorption conditions. Moreover, the adsorption data was fitted to Langmuir and second-order kinetic models as reflected by the reasonable determination coefficients of 0.9319 and 0.9726, respectively. Under the optimized conditions, the developed approach achieves good correlation coefficient of 0.9975, and 0.9981 over linearity range of 0.7-12.0 and 4.0-50.0 µg mL^-1 for both CPZ standard solutions and spiked rabbit plasma, respectively. It also provides good sensitivity expressed by the low values of limit of detection (LOD) of 0.2 and 1.2 µg mL^-1 and limit of quantitation (LOQ) of 0.7 and 4.0 µg mL^-1 for both the standard solutions and spiked plasma, respectively. The developed approach was also applied successfully for monitoring CPZ in rabbit plasma samples with satisfactory recovery % (83-110). In addition, a detailed pharmacokinetic study is performed where pharmacokinetic parameters of CPZ in rabbit plasma samples were calculated.

Preparation of polydopamine-functionalized mesoporous silica-coated core/shell magnetic nanocomposite for efficiently extracting five amphetamine-type stimulants from wastewater followed by UPLC-MS/MS determination

Wastewater-based epidemiology (WBE) was a near-real-time monitoring strategy for illegal drugs. However, solid-phase extraction (SPE) widely used in WBE was time-consuming and labor-intensive to extract ultra-trace target compounds from wastewater. In this study, a convenient magnetic solid-phase extraction (MSPE) approach based on newly designed and synthesized polydopamine functionalized core-shell magnetic mesoporous silica (Fe₃O₄@nSiO₂@mSiO₂@PDA) nanocomposite was synthesized and firstly utilized for simultaneously extracting five amphetamine-type stimulants (ATSs) from wastewater samples. Subsequently, ultrahigh performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method coupled with optimal MSPE was developed for determination of ultra-trace ATSs in wastewater. The validation results indicated a favorable linearity ranging from 1 to 200 ng L^-1, low limit of detection (0.5-2.5 ng L^-1), and qualified recovery (95.1-106.6%) and repeatability (0.6-6.2%). In addition, the Fe₃O₄@nSiO₂@mSiO₂@PDA nanoparticles could be reused for at least ten times without significant loss of the adsorption efficiencies of ATSs. Finally, the MSPE-UPLC-MS/MS method was successfully applied to real wastewater samples with the results that the preparation procedure was shrunk from 2 h to 30 min without obvious decline of extraction efficiency compared with the SPE. Hence, based on merits of the novel Fe₃O₄@nSiO₂@mSiO₂@PDA nanocomposite, the proposed method is convenient and reliable for determination of ATSs in wastewater.

Solventless Microextration Techniques for Pharmaceutical Analysis: The Greener Solution

Extensive efforts have been made in the last decades to simplify the holistic sample preparation process. The idea of maximizing the extraction efficiency along with the reduction of extraction time, minimization/elimination of hazardous solvents, and miniaturization of the extraction device, eliminating sample pre- and posttreatment steps and reducing the sample volume requirement is always the goal for an analyst as it ensures the method’s congruency with the green analytical chemistry (GAC) principles and steps toward sustainability. In this context, the microextraction techniques such as solid-phase microextraction (SPME), stir bar sorptive extraction (SBSE), microextraction by packed sorbent (MEPS), fabric phase sorptive extraction (FPSE), in-tube extraction dynamic headspace (ITEX-DHS), and PAL SPME Arrow are being very active areas of research. To help transition into wider applications, the new solventless microextraction techniques have to be commercialized, automated, and validated, and their operating principles to be anchored to theory. In this work, the benefits and drawbacks of the advanced microextraction techniques will be discussed and compared, together with their applicability to the analysis of pharmaceuticals in different matrices.

Covalent organic frameworks as multifunctional materials for chemical detection

Sensitive and selective detection of chemical and biological analytes is critical in various scientific and technological fields. As an emerging class of multifunctional materials, covalent organic frameworks (COFs) with their unique properties of chemical modularity, large surface area, high stability, low density, and tunable pore sizes and functionalities, which together define their programmable properties, show promise in advancing chemical detection. This review demonstrates the recent progress in chemical detection where COFs constitute an integral component of the achieved function. This review highlights how the unique properties of COFs can be harnessed to develop different types of chemical detection systems based on the principles of chromism, luminescence, electrical transduction, chromatography, spectrometry, and others to achieve highly sensitive and selective detection of various analytes, ranging from gases, volatiles, ions, to biomolecules. The key parameters of detection performance for target analytes are summarized, compared, and analyzed from the perspective of the detection mechanism and structure-property-performance correlations of COFs. Conclusions summarize the current accomplishments and analyze the challenges and limitations that exist for chemical detection under different mechanisms. Perspectives on how future directions of research can advance the COF-based chemical detection through innovation in novel COF design and synthesis, progress in device fabrication, and exploration of novel modes of detection are also discussed.

Magnetic nanomaterials as sorbents for trace elements analysis in environmental and biological samples

This review focuses on magnetic nanomaterials as sorbents for trace elements analysis in environmental and biological samples. The design and preparation of magnetic nanomaterials with specific functional groups for trace elemental analysis are summarized, along with relevant adsorption mechanism. The application of these magnetic sorbents in different operation modes for the quantification of trace elements and their species in environmental and biological samples are discussed. The trend of development in this field is also prospected.

1-Octyl-3-methylimidazolium hexafluorophosphate-functionalised magnetic poly β-cyclodextrin for magnetic solid-phase extraction ofpyrethroids from tea infusions

In this study, a novel sorbent, 1-octyl-3-methylimidazolium hexafluorophosphate functionalised magnetic poly β-cyclodextrin, was successfully synthesised and applied to magnetic solid-phase extraction for the determination of pyrethroids in tea infusions. The sorbent was characterised by transmission electron microscopy, energy-dispersive spectroscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, vibrating sample magnetometer and Brunauer-Emmett-Teller measurement. All factors affecting extraction efficiency, such as sorbent amount, extraction time, ionic strength and desorption conditions, were optimised individually. Under the chosen conditions, wide linearity (2.5-500 μg L^-1) with determination coefficients ranging from 0.9995 to 0.9999, low limits of detection of 0.32-0.54 μg L^-1 and good precision (intra-day: 2.6-7.0%; inter-day: 3.5-7.6%) were achieved for four pyrethroids in tea infusions. The relative recoveries of target analytes in real tea infusion samples were from 70% to 101% with relative standard deviations lower than 9.1%. We conclude that the proposed method is promising in the detection of pyrethroids in tea infusions.

Magnetic Fe3O4@SiO2@β-cyclodextrin for solid phase extraction of methyl parathion and fenthion in lettuce samples

In this study, magnetic Fe3O4@SiO2@β-cyclodextrin copolymerized microparticles were synthesized and applied for the extraction of methyl parathion and fenthion in lettuce samples followed by HPLC-UV detection. The magnetic β-cyclodextrin copolymerized microparticles were prepared by dispersion polymerization with acryloyl β-cyclodextrin as the functional monomer and ethylene glycol dimethyacrylate as the crosslinker. The composite magnetic microparticles were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, magnetic measurement, and thermogravimetric analysis, and used as the adsorbent of magnetic solid-phase extraction (MSPE) for methyl parathion and fenthion. The extraction conditions including sample pH and ionic strength, desorption solvent type and volume, and adsorption and desorption times were optimized. Under the optimal extraction conditions, an MSPE-HPLC-UV method was developed for the detection of methyl parathion and fenthion in lettuce. Wide linear ranges of 1.0-200 μg kg-1 (R2 = 0.9998) for methyl parathion and 1.5-200 μg kg-1 (R2 = 0.9978) for fenthion were obtained and the limits of detection were 0.3 μg kg-1 for methyl parathion and 0.5 μg kg-1 for fenthion in lettuce, respectively. The proposed method was applied for the determination of methyl parathion and fenthion in lettuce with satisfactory recoveries between 89.2-101.2%, and relative standard deviations were less than 9.1%. Thus, the MSPE-HPLC-UV method has high accuracy and sensitivity for the analysis of methyl parathion and fenthion in lettuce samples.

Adsorption of aflatoxins and ochratoxins in edible vegetable oils with dopamine-coated magnetic multi-walled carbon nanotubes

A new, green, and cost-effective magnetic solid-phase extraction of aflatoxins and ochratoxins from edible vegetable oils samples was developed using polydopamine-coated magnetic multi-walled carbon nanotubes (PDA@Fe₃O₄-MWCNTs) as the absorbent. PDA@Fe₃O₄-MWCNTs nanomaterials were prepared by chemical co-precipitation and in situ oxidation and self-polymerization of dopamine and was characterized. Factors affecting MSPE and the adsorption behavior of the adsorbent to mycotoxins were studied, and the optimal extraction conditions of MSPE and the complexity of the adsorption process were determined. Based on this, the magnetic solid-phase extraction-high-performance liquid chromatography-fluorescence detection method (MSPE-HPLC-FLD) was established for determining six mycotoxins [aflatoxin B₁ (AFB₁), AFB₂, AFG₁, and AFG₂, and ochratoxin A (OTA) and OTB)] in vegetable oils. The recovery was 70.15%~89.25%, and RSD was ≤6.4%. PDA@Fe₃O₄-MWCNTs showed a high affinity toward aflatoxins and ochratoxins, allowing selective extraction and quantification of aflatoxins and ochratoxins from complex sample matrices.

Novel solid-phase extraction filter based on a zirconium meta-organic framework for determination of non-steroidal anti-inflammatory drugs residues

In this study, a zirconium-based metal-organic framework UiO-66-NH₂ modified cotton fiber (CF@UiO-66-NH₂) was fabricated for the extraction of five common NSAIDs, namely ketoprofen, naproxen, flurbiprofen, diclofenac sodium, and ibuprofen. UiO-66-NH₂ was synthesized and immobilized on the surface of cotton fiber using an environmentally friendly aqueous synthesis method. The prepared CF@UiO-66-NH₂ composite of 50 mg was loaded into a 13 mm recessed filter for use as a solid-phase extraction (SPE) adsorbent material. The filter was then used to enrich NSAIDs in fish and shrimp muscle tissues followed by ultra-high performance liquid chromatography (UPLC) detection. Several key parameters were evaluated and optimized, including adsorption flow rate, pH value of sample, desorption flow rate, and the formic acid content of the eluent. Under optimized conditions, linear ranges of ketoprofen, naproxen, flurbiprofen, diclofenac sodium, and ibuprofen were 2.0-300.0 ng/mL, 1.4-280.0 ng/mL, 3.0-400.0 ng/mL, 1.0-500.0 ng/mL, and 14.0-560.0 ng/mL, respectively. The detection limits ranged from 0.12 ng/mL to 3.50 ng/mL with recoveries in the range of 72.95-116.99%, RSDs < 9.90%. The results demonstrated that the homemade filters based on CF@UiO-66-NH₂ exhibited good reproducibility, stability and adsorption property for the determination of trace-level NSAIDs in complex matrix.