Aptamer‐modified magnetic metal‐organic framework MIL‐101 for highly efficient and selective enrichment of ochratoxin A

A facile and efficient strategy is developed to modify aptamers on the surface of the magnetic metal‐organic framework MIL‐101 for the rapid magnetic solid‐phase extraction of ochratoxin A. To the best of our knowledge, this is the first attempt to create a robust aptamer‐modified magnetic MIL‐101 with covalent bonding for the magnetic separation and enrichment of ochratoxin A. The saturated adsorption of ochratoxin A by aptamer‐modified magnetic MIL‐101 was 7.9 times greater than that by magnetic metal‐organic framework MIL‐101 due to the former's high selective recognition as well as good stability. It could be used for extraction more than 12 times with no significant changes in the extraction efficiency. An aptamer‐modified magnetic MIL‐101‐based method of magnetic solid‐phase extraction combined with ultra high performance liquid chromatography with tandem mass spectrometry was developed for the determination of trace ochratoxin A with limit of detection of 0.067 ng/L. Ochratoxin A of 4.53–13.7 ng/kg was determined in corn and peanut samples. The recoveries were in the range 82.8–108% with a relative standard deviation (n = 5) of 4.5–6.5%. These results show that aptamer‐modified magnetic MIL‐101 exhibits selective and effective enrichment performance and have excellent potential for the analysis of ultra‐trace targets from complex matrices.     

Facile synthesis of a novel magnetic covalent organic frameworks for extraction and determination of five fungicides in Chinese herbal medicines

A novel magnetic covalent organic framework was synthesized via a one-step coating approach with solvothermal reaction employing 2,4,6-tris(4-aminophen-yl)-1,3,5-triazine and 2,4,6-triformylphloroglucinol as two building blocks by covalent bonding. The prepared magnetic covalent organic frameworks were properly characterized by different techniques and employed as adsorbents of magnetic solid-phase extraction. An analytical method was developed for the simultaneous determination of five fungicides in two Chinese herbal medicine samples via magnetic solid-phase extraction coupled to ultra high performance liquid chromatography with tandem mass spectrometry analysis. Under optimized magnetic solid-phase extraction conditions, the method exhibited satisfactory recoveries (74.0−109.6%) with relative standard deviations of 0.4−4.6%, low limits of detection (0.003−0.015 μg/kg), and good linearity (R² > 0.9960). Compared with the traditional extraction method, the proposed method required a lower amount of adsorbent (3 mg) and extraction time (5 min). The adsorbent also had favorable reusability (not less than eight times). Therefore, the magnetic covalent organic frameworks could be a promising adsorbent for the extraction and quantitation of fungicides in Chinese herbal medicines.     

Nonderivatization method for determination of glyphosate,glufosinate, bialaphos,and their main metabolites in environmental waters based on magnetic metal‐organic framework pretreatment

A novel magnetic metal‐organic framework composite was prepared by a self‐assembly approach. The material properties were characterized by Fourier‐transform infrared spectroscopy, vibrating sample magnetometry, thermogravimetry and differential thermogravimetric analysis, and X‐photoelectron spectroscopy. Then, the as‐prepared material was used as an adsorbent and indicated great enrichment ability toward glyphosate, glufosinate, bialaphos, and their main metabolites aminomethylphosphonic acid and 3‐methylphosphinicopropionic acid. Based on this, an efficient magnetic solid‐phase extraction method combined with ultra high performance liquid chromatography with high‐resolution mass spectrometry for the pretreatment and determination of five target compounds in environmental waters was established. Parameters that could impact on the adsorption performance had been studied in detail. The proposed method was successfully applied for the simultaneous determination of glyphosate, glufosinate, bialaphos, and their main metabolites aminomethylphosphonic acid and 3‐methylphosphinicopropionic acid in environmental water with recoveries in range of 86.2–104.6% with relative standard deviations less than 10%. Desired linearity was achieved varying from 1 to 100 μg/L for five target analytes, respectively. The limits of detection were between 0.01 and 0.03 μg/L.     

Simple magnetization of Fe3O4/MIL‐53(Al)‐NH2 for a rapid vortex‐assisted dispersive magnetic solid‐phase extraction of phenol residues in water samples

The present work describes a simple route to magnetize MIL‐53(Al)‐NH₂ sorbent for rapid extraction of phenol residues from environmental samples. To extend the applications and performances of the metal‐organic frameworks in the field of adsorption materials, we combined the properties of metal‐organic frameworks and magnetite to decrease the extraction time and simplify the extraction process as well. In this study, a simple and quick vortex‐assisted dispersive magnetic solid phase extraction method for the extraction of ten United States Environmental Protection Agency's priority phenols from water samples prior to analysis by high‐performance liquid chromatography with photodiode array detection was proposed. The developed method exhibits a rapid enrichment of the target analytes within 10 s for extraction and 10 s for desorption. Low detection limits of 1.8‐41.7 µg/L and quantitation limits of 6.0‐139.0 µg/L with the relative standard deviations for intra‐ and interday analyses less than 12% were achieved. Satisfactory recoveries in the range of 80‐111% with the relative standard deviations less than 11% demonstrated that Fe₃O₄/MIL‐53(Al)‐NH₂ is promising sorbent in the field of magnetic solid‐phase extraction for environmental samples.     

Solid‐phase purification and extraction for the determination of trace neonicotinoid pesticides in tea infusion

An analytical protocol that includes solid‐phase purification and extraction is successfully developed for the determination of trace neonicotinoid pesticides in tea infusion. The method consists of a purification on amino‐functionalized mesoporous silica SBA‐15 followed by a solid‐phase extraction based on graphene oxide before ultra high performance liquid chromatography with tandem mass spectrometry analysis. Parameters that significantly affected the extraction of the neonicotinoids onto graphene oxide, such as the amount of adsorbent, extraction time, pH, elution solvent, etc. were optimized. The amino‐functionalized mesoporous silica SBA‐15 has been proved to be an efficient adsorbent for removal of polyphenols especially catechins from tea infusion. Graphene oxide exhibits a very rapid adsorption rate (within 10 min) and high adsorption capacities for neonicotinoids at low initial concentration (0.01–0.5 mg/L). The analysis method gave a good determination coefficient (r² > 0.99) for each pesticide and high recoveries in the range of 72.2–95.0%. Powder X‐ray diffraction, Raman spectroscopy, transmission electron microscopy, and UV‐vis spectroscopy were utilized to identify the structure and morphology of graphene oxide. The adsorption driving force of neonicotinoids on graphene oxide mainly depends on π–π electron donor–acceptor interaction and electrostatic interaction.     

Magnetic solid‐phase extraction of benzoylurea insecticides by Fe3O4 nanoparticles decorated with a hyper‐cross‐linked porous organic polymer

A magnetic polytriphenylamine porous organic polymer was prepared through simple self‐polycondensation of triphenylamine followed by coprecipitation with Fe²⁺ and Fe³⁺. It was applied as a magnetic adsorbent for the extraction of six benzoylurea insecticides from tomato, cucumber, and watermelon samples before their high‐performance liquid chromatography and mass spectral detection. Under the optimized experimental conditions, the established method gave a low limit of detection ranging from 0.05 to 0.1 ng/g and a good linear response ranging from 0.2 to 40 ng/g with coefficients of determination >0.99. The method recoveries for spiked analytes at the concentrations of 3 and 15 ng/g in real samples were in the range of 87.7–106.7% with the relative standard deviations <6.4%. The results indicated that it had a good adsorption capability toward the target analytes due to the π‐stacking and hydrogen bonding interactions. The polymer material showed great potential in the efficient extraction of organic compounds from real samples with complex matrixes.     

Synthesis of polydopamine‐functionalized magnetic graphene and carbon nanotubes hybrid nanocomposites as an adsorbent for the fast determination of 16 priority polycyclic aromatic hydrocarbons in aqueous samples

A novel adsorbent made of polydopamine‐functionalized magnetic graphene and carbon nanotubes hybrid nanocomposite was synthesized and applied to determine 16 priority polycyclic aromatic hydrocarbons by magnetic solid phase extraction in water samples. FTIR spectroscopy, transmission electron microscopy, scanning electron microscopy, and Raman spectroscopy consistently indicate that the synthesized adsorbents are made of core–shell nanoparticles well dispersed on the surface of graphene and carbon nanotubes. The major factors affecting the extraction efficiency, including the pH value of samples, the amount of adsorbent, adsorption time and desorption time, type and volume of desorption solvent, were systematically optimized. Under the optimum extraction conditions, a linear response was obtained for polycyclic aromatic hydrocarbons between concentrations of 10 and 500 ng/L with the correlation coefficients ranging from 0.9958 to 0.9989, and the limits of detection (S/N = 3) were between 0.1 and 3.0 ng/L. Satisfactory results were also obtained when applying these magnetic graphene/carbon nanotubes/polydopamine hybrid nanocomposites to detect polycyclic aromatic hydrocarbons in several environmental aqueous samples.     

Comparisons of glyphosate adsorption properties of different functional Cr‐based metal–organic frameworks

A Cr‐based metal–organic framework, namely, MIL‐101(Cr), was modified with amino (NH₂–) and urea (UR₂–) groups, and the materials were evaluated as adsorbents for glyphosate, and a comparison with commercial activated carbon was also discussed. The effects of the adsorption factors, such as adsorbent concentration, adsorption time, pH and ionic strength were mainly investigated. The results showed that a pseudo‐second‐order rate equation described the adsorption kinetics mechanisms well, while the Langmuir model and the Freundlich model fitted different adsorption isotherms, respectively. Among the adsorbents we studied, NH₂‐MIL‐101(Cr) showed the maximum adsorbing capacity, which is 64.25 mg/g when pH = 3.0, while UR₂‐MIL‐101(Cr) did not reach the best adsorption performance due to the steric hindrance. The work opens up a new way for the modification of metal–organic frameworks for adsorption process.     

l‐Cysteine‐modified magnetic microspheres for extraction and quantification of saxitoxin in rat plasma with liquid chromatography and tandem mass spectrometry

Saxitoxin, which is one of the most typical paralytic shellfish poisoning toxins, ranks the highest intoxication rate of marine biological poisoning cases globally. Efficient clean‐up and extraction of saxitoxin from complex biological matrices are imperative for the analysis and concentration monitoring of the toxin when correlative poisoning cases happen. Herein, l ‐cysteine‐modified magnetic microspheres based on metal‐organic coordination were synthesized by a facile approach and applied for magnetic solid‐phase extraction of saxitoxin from rat plasma samples before liquid chromatography–tandem mass spectrometry detection. Parameters, including adsorbent amount, extraction time, desorption solution, and desorption time that could affect the extraction efficiency, were respectively investigated. The developed method demonstrated good linearity in the range of 5–300 ng/mL (R² = 0.9985) with a limit of quantification of 5 ng/mL and a limit of detection of 0.5 ng/mL, acceptable accuracy. and precision of within‐run and between‐run.     

Loading controlled magnetic carbon dots for microwave‐assisted solid‐phase extraction: Preparation,extraction evaluation and applications in environmental aqueous samples

An adsorbent of carbon dot@poly(glycidyl methacrylate)@Fe₃O₄ nanoparticles has been developed for the microwave‐assisted magnetic solid‐phase extraction of polycyclic aromatic hydrocarbons in environmental aqueous samples prior to high‐performance liquid chromatography with UV/visible spectroscopy detection. Poly(glycidyl methacrylate) was synthesized by atom transfer radical polymerization. The chain length and amount of carbon dots attached on them can be easily controlled through changing polymerization conditions, which contributes to tunable extraction performance. The successful fabrication of the nano‐adsorbent was confirmed by transmission electronic microscopy, Fourier transform infrared spectroscopy, Raman spectroscopy and vibrating sample magnetometry. The extraction performance of the adsorbent was evaluated by using polycyclic aromatic hydrocarbons as model analytes. The key factors influencing the extraction, such as microwave power, adsorption time, desorption time and desorption solvents were investigated in detail. Under the optimal conditions, the microwave‐assisted method afforded magnetic solid‐phase extraction with short extraction time, wide dynamic linear range (0.02–200 μg/L), good linearity (R² ≥ 98.57%) and low detection limits (20–90 ng/L) for model analytes. The adsorbent was successfully applied for analyzing polycyclic aromatic hydrocarbons in environmental aqueous samples and the recoveries were in the range of 86.0–124.2%. Thus, the proposed method is a promising candidate for fast and reliable preconcentration of trace polycyclic aromatic hydrocarbons in real water samples.     

Analysis of microcystins using high‐performance liquid chromatography and magnetic solid‐phase extraction with silica‐coated magnetite with cetylpyridinium chloride

Microcystins (MCs), produced by freshwater cyanobacteria, can be serious water pollutants, so it is important to monitor their concentration in drinking water. We have developed a method for rapid and accurate determination of microcystin levels in environmental water, using magnetic solid‐phase extraction and high‐performance liquid chromatography with UV detection. The magnetic composite material, which was combined with cetylpyridinium chloride, was prepared by hydrothermal synthesis. The optimal extraction of microcystins in water sample was achieved by optimizing the amount of adsorbent, time of adsorption, ratio of eluting solvent, and volume of eluent. Under the optimal conditions, the limit of detection of MC‐LR was 0.001 μg/L, and the limit of quantification was 0.0028 μg/L. The limit of detection of MC‐RR was 0.001 μg/L, and the limit of quantification was 0.003 μg/L. These values are far lower than those established by the International Health Organization for the maximum concentration of microcystins in drinking water. The magnetic solid‐phase extraction adsorbent used in this method has the advantages of simple preparation, low price, and easy solid–liquid separation, and it can be used for the rapid and sensitive monitoring of trace microcystins in environmental water samples.     

Rapid magnetic solid‐phase extraction of Congo Red and Basic Red 2 from aqueous solution by ZIF‐8@CoFe2O4 hybrid composites

Core–shell metal–organic framework materials have attracted considerable attention mainly due to their enhanced or new physicochemical properties compared with their single‐component counterparts. In this work, a core–shell heterostructure of CoFe₂O₄‐Zeolitic Imidazolate Framework‐8 (ZIF‐8@CoFe₂O₄) is successfully fabricated and used as an solid‐phase extraction adsorbent to efficiently extract Congo Red and Basic Red 2 dyes from contaminated aqueous solution. Vibrating sample magnetometry indicates that the saturated magnetization of ZIF‐8@CoFe₂O₄ is 3.3 emu/g, which is large enough for magnetic separation. The obtained hybrid magnetic metal‐organic framework based material ZIF‐8@CoFe₂O₄ can remove the investigated dyes very fast within 1 min of the contact time. The adsorbent ZIF‐8@CoFe₂O₄ also shows a good reusability. After regeneration, the adsorbent can still exhibit high removal efficiency (～97%) toward Congo Red for five cycles of desorption–adsorption. This work reveals the great potential of core–shell ZIF‐8@CoFe₂O₄ sorbents for the fast separation and preconcentration of organic pollutants in aqueous solution before high‐performance liquid chromatography analysis.     

Magnetic N‐doped mesoporous carbon as an adsorbent for the magnetic solid‐phase extraction of phthalate esters from soft drinks

A new kind of magnetic N‐doped mesoporous carbon was prepared by the one‐step carbonization of a hybrid precursor (glucose, melamine, and iron chloride) in a N₂ atmosphere with a eutectic salt (KCl/ZnCl₂) as the porogen. The obtained magnetic N‐doped mesoporous carbon showed excellent characteristics, such as strong magnetic response, high surface area, large pore volume, and abundant π‐electron system, which endow it with a great potential as a magnetic solid‐phase extraction adsorbent. To evaluate its adsorption performance, the magnetic N‐doped mesoporous carbon was used for the extraction of three phthalate esters from soft drink samples followed by high‐performance liquid chromatographic analysis. Under the optimum conditions, the developed method showed a good linearity (1.0–120.0 ng/mL), low limit of detection (0.1–0.3 ng/mL, S/N = 3), and good recoveries (83.2–119.0%) in soft drink samples. The results indicated that the magnetic N‐doped mesoporous carbon has an excellent adsorption capacity for phthalate esters and the present method is simple, accurate, and highly efficient for the extraction and determination of phthalate esters in complex matrix samples.     

Magnetic core micelles as a nanosorbent for the efficient removal and recovery of three organophosphorus pesticides from fruit juice and environmental water samples

Sodium dodecyl sulfate coated amino‐functionalized magnetic iron oxide nanoparticles were used as an efficient adsorbent for rapid removal and preconcentration of three important organophosphorus pesticides, chlorpyrifos, diazinon and phosalone, by ultrasound‐assisted dispersive magnetic solid‐phase microextraction. Fabrication of amino‐functionalized magnetic nanoparticles was certified by characteristic analyses, including Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, and transmission electron microscopy. Affecting parameters on the removal efficiency were investigated and optimized through half‐fractional factorial design and Doehlert design, respectively. The analysis of analytes was performed by high‐performance liquid chromatography with ultraviolet detection. Under the optimum conditions, extraction recoveries for 20 ng/mL of organophosphorus pesticides were in the range of 84–97% with preconcentration factors in the range of 134–155. Replicating the experiment in above condition for five times gave the relative standard deviations <6%. The calibration curves showed high linearity in the range of 0.2–700 ng/mL and the limits of detection were in the range of 0.08–0.13 ng/mL. The proposed method was successfully applied for both removal and trace determination of these three organophosphorus pesticides in environmental water and fruit juice samples.     

Facile preparation of a high‐capacity boronate‐affinity adsorbent based on low‐cost commercial supports for selective enrichment of cis‐diol‐containing biomolecules

Boronate‐affinity adsorbents have been regarded as favorable extraction adsorbents for the pretreatment of cis‐diol‐containing biomolecules owning to their specific selectivity, but most of them have low adsorption capacity and a tedious synthesis methods. In this study, a new boronate‐affinity material (PGMA@FPBA) with high adsorption capacity was synthesized via a “one‐pot” method based on a low‐cost commercial support. The PGMA@FPBA was characterized by Fourier transform infrared spectroscopy (FT‐IR), X‐ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), and nitrogen adsorption/desorption measurements. The as‐prepared adsorbent showed good selectivity, high adsorption capacity (448 μmol/g for catechol), and fast adsorption equilibration (1 min) for cis‐diol‐containing biomolecules. Subsequently, as an example for application, the obtained PGMA@FPBA was used as a dispersive solid‐phase extraction (d‐SPE) adsorbent for enrichment of quercetin in red wine. The results indicated that the facile‐prepared boronate‐affinity adsorbent has great potential application for separation and enrichment of cis‐diol‐containing biomolecules in complex samples.     

One‐step synthesized magnetic MIL‐101(Cr) for effective extraction of triazine herbicides from rice prior to determination by liquid chromatography‐tandem mass spectrometry

The magnetic metal‐organic framework MIL‐101(Cr) material‐based solid‐phase extraction method coupled with high‐performance liquid chromatography and tandem mass spectrometry was applied to extract seven triazine herbicides in rices. Fe₃O₄/MIL‐101(Cr) was synthesized using reduction‐precipitation method, in which steps including pre‐synthesis and modification of Fe₃O₄ nanoparticles were by‐passed. Various parameters including extraction solvent type and volume, ultrasonic extraction time, amount of Fe₃O₄/MIL‐101(Cr) microspheres, adsorption time, desorption volume and time were investigated. Under optimal conditions, the proposed method had the limit of detection (S/N = 3) and the limit of quantification (S/N = 10) of 1.08–18.10 and 3.60–60.20 pg/g, respectively. Relative standard deviations calculated for all herbicides with concentrations of 2 and 20 ng/g were in the range of 0.5 to 13% (n = 3). In addition, at the two above‐mentioned concentrations, the method achieved relative recoveries percentages of 79.3 to 116.7% when applied to determine the triazine herbicides in real samples spiked. This rapid, green, non‐polluting, pre‐concentrated extraction method was successfully developed and applied to analyze herbicides in rice samples.     

Surface‐initiated atom transfer radical polymerization of a new rhodanine‐based monomer for rapid magnetic removal of Co(II) ions from aqueous solutions

The present study reports synthesis and characterization of a new acrylamide‐based monomer containing rhodanine moiety, N‐3‐amino‐thiazolidine‐4‐one‐acrylamide (ATA). Poly(ATA)‐grafted magnetite nanoparticles (poly(ATA)‐g‐MNPs) were prepared using surface‐initiated atom transfer radical polymerization of the monomer on Fe₃O₄ nanoparticles. The grafted nanoparticles were characterized by Fourier transform infrared analysis, scanning electron microscopy, X‐ray diffraction, and vibrating sample magnetometry. The amount of the grafted polymer was 209 mg g⁻¹, as calculated from thermogravimetric analysis experiment. The capability of poly(ATA)‐g‐MNPs to remove Co(II) cations was shown under optimal conditions of contact time, pH, adsorbent dosage, and initial Co(II) concentration. About 86% of the Co(II) cations were removed over 7 minutes. The adsorption kinetics obeyed the pseudo–second‐order kinetic equation, and the Langmuir isotherm model best described the adsorption isotherm with a maximum adsorption capacity of 3.62 mg g⁻¹. The thermodynamic investigation showed spontaneous nature of the adsorption process (ΔG = −2.90 kJ mol⁻¹ at 25°C ± 1°C). In addition, the poly(ATA)‐g‐MNPs were regenerated by simply washing with an aqueous 0.1M HCl solution. The study of the reusability of the prepared magnetic sorbent revealed that the sorbent can be reused without a significant decrease in the extraction efficiency and be recovered by 95.4% after 7 cycles. These findings suggest that the grafted nanoparticles are stable and reusable adsorbent and can be potentially applied to water treatment in efficient removal of Co(II) cations.     

Magnetic porous carbon derived from Co‐doped metal–organic frameworks for the magnetic solid‐phase extraction of endocrine disrupting chemicals

Metal–organic frameworks‐5 (MOF‐5) was explored as a template to prepare porous carbon due to its high surface area, large pore volume, and permanent nanoscale porosity. Magnetic porous carbon, Co@MOF‐5‐C, was fabricated by the one‐step direct carbonization of Co‐doped MOF‐5. After carbonization, the magnetic cobalt nanoparticles are well dispersed in the porous carbon matrix, and Co@MOF‐5‐C displays strong magnetism (with the saturation magnetization intensity of 70.17emu/g), high‐specific surface area, and large pore volume. To evaluate its extraction performance, the Co@MOF‐5‐C was applied as an adsorbent for the magnetic solid‐phase extraction of endocrine disrupting chemicals, followed by their analysis with high‐performance liquid chromatography. The developed method exhibits a good linear response in the range of 0.5–100 ng/mL for pond water and 1.0–100 ng/mL for juice samples. The limits of detection (S/N  = 3) for the analytes were in the range of 0.1–0.2 ng/mL.     

Graphene‐coated magnetic‐sheet solid‐phase extraction followed by high‐performance liquid chromatography with fluorescence detection for the determination of aflatoxins B1, B2, G1, and G2 in soy‐based samples

A new method named graphene‐coated magnetic‐sheet solid‐phase extraction based on a magnetic three‐dimensional graphene sorbent was developed for the extraction of aflatoxins prior to high‐performance liquid chromatography with fluorescence detection. The use of a perforated magnetic‐sheet for fixing the magnetic nanoparticles is a new feature of the method. Hence, the adsorbent particles can be separated from sample solution without using an external magnetic field. This made the procedure very simple and easy to operate so that all steps of the extraction process (sample loading, washing, and desorption) were carried out continuously using two lab‐made syringe pumps. The factors affecting the performance of extraction procedure such as the extraction solvent, adsorbent dose, sample loading flow rate, ionic strength, pH, and desorption parameters were investigated and optimized. Under the optimal conditions, the obtained enrichment factors and limits of detection were in the range of 205–236 and 0.09–0.15 μg/kg, respectively. The relative standard deviations were <3.4 and 7.5% for the intraday (n = 6) and interday (n = 4) precisions, respectively. The developed method was successfully applied to determine aflatoxins B₁, B₂, G₁, and G₂ in different soy‐based food samples.     

Electroless‐coated magnetic three‐dimensional graphene with silver nanoparticles used for the determination of pesticides in fruit samples

A new type of adsorbent composed of magnetic three‐dimensional graphene coated with silver nanoparticles was synthesized by an electroless technique and used in the magnetic solid‐phase extraction of selected pesticides (fenitrothion, chlorpyrifos, and hexaconazole) before gas chromatography with a micro‐electron capture detector. The adsorbent was characterized using Fourier‐transform infrared spectroscopy, X‐ray diffraction, vibrating sample magnetometry, and field‐emission scanning electron microscopy. The important extraction parameters such as pH, adsorbent dose, extraction time, and desorption conditions were investigated. Under the optimal conditions, the analytical figures of merit were obtained as: linear dynamic range of 0.1–5 ng/g with determination coefficients of 0.991–0.996; limit of detection of 0.07–0.13 ng/g; limit of quantification of 0.242–0.448 ng/g; and the intraday and interday relative standard deviations (C = 5 ng/g, n = 3) were 3.8–8.7 and 6.6–8.9%, respectively. The developed method was successfully applied for analysis of the selected pesticides in tomato and grape with extraction recoveries in the range of 72.8–109.6%.