Determination of four sulfonylurea herbicides in tea by matrix solid‐phase dispersion cleanup followed by dispersive liquid–liquid microextraction

Matrix solid‐phase dispersion combined with dispersive liquid–liquid microextraction has been developed as a new sample pretreatment method for the determination of four sulfonylurea herbicides (chlorsulfuron, bensulfuron‐methyl, chlorimuron‐ethyl, and pyrazosulfuron) in tea by high‐performance liquid chromatography with diode array detection. The extraction and cleanup by matrix solid‐phase dispersion was carried out by using CN‐silica as dispersant and carbon nanotubes as cleanup sorbent eluted with acidified dichloromethane. The eluent of matrix solid‐phase dispersion was evaporated and redissolved in 0.5 mL methanol, and used as the dispersive solvent of the following dispersive liquid–liquid microextraction procedure for further purification and enrichment of the target analytes before high‐performance liquid chromatography analysis. Under the optimum conditions, the method yielded a linear calibration curve in the concentration range from 5.0 to 10 000 ng/g for target analytes with a correlation coefficients (r²) ranging from 0.9959 to 0.9998. The limits of detection for the analytes were in the range of 1.31–2.81 ng/g. Recoveries of the four sulfonylurea herbicides at two fortification levels were between 72.8 and 110.6% with relative standard deviations lower than 6.95%. The method was successfully applied to the analysis of four sulfonylurea herbicides in several tea samples.     

Ionic‐liquid‐based dispersive liquid–liquid microextraction coupled with high‐performance liquid chromatography for the forensic determination of methamphetamine in human urine

Determination of methamphetamine in forensic laboratories is a major issue due to its health and social harm. In this work, a simple, sensitive, and environmentally friendly method based on ionic liquid dispersive liquid–liquid microextraction combined with high‐performance liquid chromatography was established for the analysis of methamphetamine in human urine. 1‐Octyl‐3‐methylimidazolium hexafluorophosphate with the help of disperser solvent methanol was selected as the microextraction solvent in this process. Various parameters affecting the extraction efficiency of methamphetamine were investigated systemically, including extraction solvent and its volume, disperser solvent and its volume, sample pH, extraction temperature, and centrifugal time. Under the optimized conditions, a good linearity was obtained in the concentration range of 10–1000 ng/mL with determination coefficient >0.99. The limit of detection calculated at a signal‐to‐noise ratio of 3 was 1.7 ng/mL and the relative standard deviations for six replicate experiments at three different concentration levels of 100, 500, and 1000 ng/mL were 6.4, 4.5, and 4.7%, respectively. Meanwhile, up to 220‐fold enrichment factor of methamphetamine and acceptable extraction recovery (>80.0%) could be achieved. Furthermore, this method has been successfully employed for the sensitive detection of a urine sample from a suspected drug abuser.     

Using magnetic core‐shell nanoparticles coated with an ionic liquid dispersion assisted by effervescence powder for the micro‐solid‐phase extraction of four beta blockers from human plasma by ultra high performance liquid chromatography with mass spectrometry detection

In this work, a novel, efficient, and green sorbent, SiO₂@Fe₃O₄ has been created and functionalized with 1‐butyl‐3‐methylimidazolium hexafluorophosphate as an ionic liquid. This sorbent was applied for microextraction of four beta blockers, propranolol, metoprolol, atenolol, and alprenolol with bupivacaine as internal standard from human plasma followed by liquid chromatography with mass spectrometric detection. A mixture of sodium bicarbonate and sodium dihydrogen phosphate was used as an extractant dispersive agent (effervescent power) to enhance the interaction between the magnetic sorbent and analytes. Main affecting parameters on microextraction and elution were optimized. Figures of merit for dispersive solid phase extraction with ionic liquid coated magnetic nanoparticles assisted by effervescent powder were calculated under the optimized conditions. The detection limits for propranolol, metoprolol, atenolol, and alprenolol were found at 0.33, 0.62, 0.03, and 0.44 ng/mL, respectively. For all analytes, good linearity was obtained. Intra‐ (n = 5) and interday (n = 10) precision were both under 6.3% while the preconcentration factors were obtained in the range between 15–18. The extraction efficiencies for each analyte ranged from 75 to 91%. The method was successfully applied for determination of trace amounts of the beta blockers in human plasma samples.     

Magnetic solid‐phase extraction or dispersive liquid–liquid microextraction for pyrethroid determination in environmental samples

The determination of 15 pyrethroids in soil and water samples was carried out by gas chromatography with mass spectrometry. Compounds were extracted from the soil samples (4 g) using solid–liquid extraction and then salting‐out assisted liquid–liquid extraction. The acetonitrile phase obtained (0.8 mL) was used as a dispersant solvent, to which 75 μL of chloroform was added as an extractant solvent, submitting the mixture to dispersive liquid–liquid microextraction. For the analysis of water samples (40 mL), magnetic solid‐phase extraction was performed using nanocomposites of magnetic nanoparticles and multiwalled carbon nanotubes as sorbent material (10 mg). The mixture was shaken for 45 min at room temperature before separation with a magnet and desorption with 3 mL of acetone using ultrasounds for 5 min. The solvent was evaporated and reconstituted with 100 μL acetonitrile before injection. Matrix‐matched calibration is recommended for quantification of soil samples, while water samples can be quantified by standards calibration. The limits of detection were in the range of 0.03–0.5 ng/g (soil) and 0.09–0.24 ng/mL (water), depending on the analyte. The analyzed environmental samples did not contain the studied pyrethroids, at least above the corresponding limits of detection.     

Up‐and‐down shaker‐assisted ionic liquid‐based dispersive liquid—liquid microextraction of benzophenone‐type ultraviolet filters

Sun protection is an important part of our lives. UV filters are widely used to absorb solar radiation in sunscreens. However, excess UV filters constitute persistent groups of organic micropollutants present in the environment. An environmentally friendly ionic‐liquid‐based up‐and‐down shaker‐assisted dispersive liquid?liquid microextraction device combined with ultra‐performance liquid chromatography coupled with photodiode‐array detection has been developed to preconcentrate three UV filters (benzophenone, 2‐hydroxy‐4‐methoxybenzophenone, 2,2′‐dihydroxy‐4‐methoxybenzophenone) from field water samples. In this method, the optimal conditions for the proposed extraction method were: 40 μL [C₈MIM][PF₆] as extraction solvent and 200 μL methanol as disperser solvent were used to extract the UV filters. After up‐and‐down shaking for 3 min, the aqueous solution was centrifuged at 5000 rpm speed, then using microtube to collect the settled extraction solvent and using ultra‐performance liquid chromatography for further analysis. Quantification results indicated that the linear range was 2–1000 ng/mL. The LOD of this method was in the range 0.2–1.3 ng/mL with r² ≥ 0.9993. The relative recovery in studies of different types of field water samples was in the range 92–120%, and the RSD was 2.3–7.1%. The proposed method was also applied to the analysis of field samples.     

Double dispersant‐assisted ionic liquid dispersive liquid–liquid microextraction coupled with capillary electrophoresis for the determination of benzophenone‐type ultraviolet filters in sunscreen cosmetic product

In this work, double dispersant‐assisted ionic liquid dispersive liquid–liquid microextraction coupled with micellar electrokinetic chromatography was developed to determine four UV filters (benzophenone, 4‐hydroxybenzophenone, 2,4‐dihydroxybenzophenone, and 2‐hydroxy‐4‐methoxybenzophenone). 1‐Hexyl‐3‐methylimidazolium hexafluorophosphate was used as the extraction solvent. The main novelty of the present work was that acetonitrile‐Triton X‐114 was used as double disperser solvent. Parameters affected the extraction efficiency were investigated and optimized. Under the optimum conditions, enrichment factors were in the range of 25.3?40.5. The limits of detection and quantitation, calculated at a S/N of three and ten, were 3.9?6.7 ng/mL and 13.0?22.3 ng/mL. The linearity of the method was in the range of 0.02?2 μg/mL for 2, 4‐dihydroxybenzophenone and 4‐hydroxybenzophenone, 0.01?2 μg/mL for benzophenone and 2‐hydroxy‐4‐methoxybenzophenone, with correlation coefficient (R²) of 0.9984?0.9991. The proposed method was successfully applied to the determination of four benzophenone‐type UV filters in six kinds of sunscreen cosmetic products, with yielded relative recoveries ranging from 80.2 to 117.7%.     

Dispersive solid‐phase extraction followed by vortex‐assisted dispersive liquid–liquid microextraction based on the solidification of a floating organic droplet for the determination of benzoylurea insecticides in soil and sewage sludge

A novel dispersive solid‐phase extraction combined with vortex‐assisted dispersive liquid–liquid microextraction based on solidification of floating organic droplet was developed for the determination of eight benzoylurea insecticides in soil and sewage sludge samples before high‐performance liquid chromatography with ultraviolet detection. The analytes were first extracted from the soil and sludge samples into acetone under optimized pretreatment conditions. Clean‐up of the extract was conducted by dispersive solid‐phase extraction using activated carbon as the sorbent. The vortex‐assisted dispersive liquid–liquid microextraction based on solidification of floating organic droplet procedure was performed by using 1‐undecanol with lower density than water as the extraction solvent, and the acetone contained in the solution also acted as dispersive solvent. Under the optimum conditions, the linearity of the method was in the range 2–500 ng/g with correlation coefficients (r) of 0.9993–0.9999. The limits of detection were in the range of 0.08–0.56 ng/g. The relative standard deviations varied from 2.16 to 6.26% (n = 5). The enrichment factors ranged from 104 to 118. The extraction recoveries ranged from 81.05 to 97.82% for all of the analytes. The good performance has demonstrated that the proposed methodology has a strong potential for application in the multiresidue analysis of complex matrices.     

Matrix solid‐phase dispersion with chitosan‐zinc oxide nanoparticles combined with flotation‐assisted dispersive liquid–liquid microextraction for the determination of 13 n‐alkanes in soil samples

In this study, chitosan‐zinc oxide nanoparticles were used as a sorbent of miniaturized matrix solid‐phase dispersion combined with flotation‐assisted dispersive liquid–liquid microextraction for the simultaneous determination of 13 n‐alkanes such as C₈H₁₈ and C₂₀H₄₂ in soil samples. The solid samples were directly blended with the chitosan nanoparticles in the solid‐phase dispersion method. The eluent of solid‐phase dispersion was applied as the dispersive solvent for the following flotation‐assisted dispersive liquid–liquid microextraction for further purification and enrichment of the target compounds prior to gas chromatography with flame ionization detection. Under the optimum conditions, good linearity with correlation coefficients in the range 0.9991 < r² < 0.9995 and low detection limits between 0.08 to 2.5 ng/g were achieved. The presented procedure combined the advantages of chitosan‐zinc oxide nanoparticles, solid‐phase dispersion and flotation‐assisted dispersive liquid–liquid microextraction, and could be applied for the determination of n‐alkanes in complicated soil samples with acceptable recoveries.     

Dispersion‐solidification liquid–liquid microextraction for volatile aromatic hydrocarbons determination: Comparison with liquid phase microextraction based on the solidification of a floating drop

Two microextraction techniques – liquid phase microextraction based on solidification of a floating organic drop (LPME‐SFO) and dispersive liquid–liquid microextraction combined with a solidification of a floating organic drop (DLLME‐SFO) – are explored for benzene, toluene, ethylbenzene and o‐xylene sampling and preconcentration. The investigation covers the effects of extraction solvent type, extraction and disperser solvents' volume, and the extraction time. For both techniques 1‐undecanol containing n‐heptane as internal standard was used as an extracting solvent. For DLLME‐SFO acetone was used as a disperser solvent. The calibration curves for both techniques and for all the analytes were linear up to 10 μg/mL, correlation coefficients were in the range 0.997–0.998, enrichment factors were from 87 for benzene to 290 for o‐xylene, detection limits were from 0.31 and 0.35 μg/L for benzene to 0.15 and 0.10 μg/L for o‐xylene for LPME‐SFO and DLLME‐SFO, respectively. Repeatabilities of the results were acceptable with RSDs up to 12%. Being comparable with LPME‐SFO in the analytical characteristics, DLLME‐SFO is superior to LPME‐SFO in the extraction time. A possibility to apply the proposed techniques for volatile aromatic hydrocarbons determination in tap water and snow was demonstrated.     

New approach applying a pet fish air pump in liquid‐phase microextraction for the determination of Sudan dyes in food samples by HPLC

A new approach applying a pet fish air pump is introduced to develop an extraction method, namely, air‐pump‐enhanced emulsion, followed by salt‐assisted emulsion breaking based on solidified floating organic drop microextraction for the extraction and preconcentration of Sudan I–IV before high‐performance liquid chromatography. The applicability of this method was successfully demonstrated by determination of these dyes in four chili products that include chili powder, chili oil, chili sauce, and chili paste. An enrichment factor of 62 was obtained only with a sample solution of 5 mL. A linear range of 0.5–2500 ng/mL was obtained with a limit of detection of 0.16–0.24 ng/mL and recovery of 90–110%. This method is superior to other liquid–liquid extraction methods, as is simple, rapid, environmental friendly, and its phase separation needs no centrifugation. It also needs no disperser solvent and requires less organic solvent, and satisfies the criteria to be called as a green extraction. Therefore, this facile extraction method can be successfully applied in the determination of Sudan dyes in food samples.     

Trace determination of five triazole fungicide residues in traditional Chinese medicine samples by dispersive solid‐phase extraction combined with ultrasound‐assisted dispersive liquid–liquid microextraction and UHPLC–MS/MS

A novel and reliable method for determination of five triazole fungicide residues (triadimenol, tebuconazole, diniconazole, flutriafol, and hexaconazol) in traditional Chinese medicine samples was developed using dispersive solid‐phase extraction combined with ultrasound‐assisted dispersive liquid–liquid microextraction before ultra‐high performance liquid chromatography with tandem mass spectrometry. The clean up of the extract was conducted using dispersive solid‐phase extraction by directly adding sorbents into the extraction solution, followed by shaking and centrifugation. After that, a mixture of 400 μL trichloromethane (extraction solvent) and 0.5 mL of the above supernatant was injected rapidly into water for the dispersive liquid–liquid microextraction procedure. The factors affecting the extraction efficiency were optimized. Under the optimum conditions, the calibration curves showed good linearity in the range of 2.0–400 (tebuconazole, diniconazole, and hexaconazole) and 4.0–800 ng/g (triadimenol and flutriafol) with the regression coefficients higher than 0.9958. The limit of detection and limit of quantification for the present method were 0.5–1.1 and 1.8–4.0 ng/g, respectively. The recoveries of the target analytes ranged from 80.2 to 103.2%. The proposed method has been successfully applied to the analysis of five triazole fungicides in traditional Chinese medicine samples, and satisfactory results were obtained.     

Centrifugeless ultrasound‐assisted emulsification microextraction based on salting‐out phenomenon followed by high‐performance liquid chromatography for the simple determination of phthalate esters in aqueous samples

A fast, sensitive, and centrifugeless ultrasound‐assisted emulsification microextraction followed by a high‐performance liquid chromatography method is developed for the determination of some phthalate esters in aqueous samples. In this method, a simple approach is followed to eliminate the centrifugation step in dispersive liquid–liquid microextraction using an organic solvent whose melting point is near the ambient temperature, consumption of the extracting solvent is efficiently reduced, and the overall extraction time was found to be only 7 min. The variables affecting the method are optimized. Under the optimal experimental conditions (75 μL of 1‐undecanol, a flow rate of 2.0 mL/min, and an ultrasound irradiation of 1 min), the proposed method exhibits good preconcentration factors (52–97), low limits of detection (1.0–5.0 ng/mL), and linearities in the range of 5–1500 ng/mL (r ² ≥ 0.995). Finally, the method is successfully applied to the analysis of phthalate esters in the drinking and river water samples. To study the probable release of the phthalate esters from a polyethylene container into boiling water, the boiling water exposed to the polyethylene container was analyzed by the proposed method.     

Preconcentration and determination of 2‐mercaptobenzimidazole by dispersive liquid–liquid microextraction and experimental design

A method was developed to determine 2‐mercaptobenzimidazole in water and urine samples using dispersive liquid–liquid microextraction technique coupled with ultraviolet–visible spectrophotometry. It was essential to peruse the effect of all parameters that can likely influence the performance of extraction. The influence of parameters, such as dispersive and extraction solvent volume and sample volume, on dispersive liquid–liquid microextraction was studied. The optimization was carried out by the central composite design method. The central composite design optimization method resulted in 1.10 mL dispersive solvent, 138.46 μL extraction solvent, and 4.46 mL sample volume. Under the optimal terms, the calibration curve was linear over the range of 0.003–0.18 and 0.007–0.18 μg/mL in water and urine samples, respectively. The limit of detection and quantification of the proposed approach for 2‐mercaptobenzimidazole were 0.013 and 0.044 μg/mL in water samples and 0.016 and 0.052 μg/mL in urine samples, respectively. The method was successfully applied to determination of 2‐mercaptobenzimidazole in urine and water samples.     

An efficient biosorption‐based dispersive liquid‐liquid microextraction with extractant removal by magnetic nanoparticles for quantification of bisphenol A in water samples by gas chromatography‐mass spectrometry detection

In this work, a simple, fast, sensitive, and environmentally friendly method was developed for preconcentration and quantitative measurement of bisphenol A in water samples using gas chromatography with mass spectrometry. The preconcentration approach, namely biosorption‐based dispersive liquid‐liquid microextraction with extractant removal by magnetic nanoparticles was performed based on the formation of microdroplet of rhamnolipid biosurfactant throughout the aqueous samples, which accelerates the mass transfer process between the extraction solvent and sample solution. The process is then followed by the application of magnetic nanoparticles for easy retrieval of the analyte‐containing extraction solvent. Several important variables were optimized comprehensively including type of disperser solvent and desorption solvent, rhamnolipid concentration, volume of disperser solvent, amount of magnetic nanoparticles, extraction time, desorption time, ionic strength, and sample pH. Under the optimized microextraction and gas chromatography with mass spectrometry conditions, the method demonstrated good linearity over the range of 0.5–500 µg/L with a coefficient of determination of R² = 0.9904, low limit of detection (0.15 µg/L) and limit of quantification (0.50 µg/L) of bisphenol A, good analyte recoveries (84–120%) and acceptable relative standard deviation (1.8–14.9%, n = 6). The proposed method was successfully applied to three environmental water samples, and bisphenol A was detected in all samples.     

Optimization of alcohol‐assisted dispersive liquid–liquid microextraction by experimental design for the rapid determination of fluoxetine in biological samples

A sensitive and rapid method based on alcohol‐assisted dispersive liquid–liquid microextraction followed by high‐performance liquid chromatography for the determination of fluoxetine in human plasma and urine samples was developed. The effects of six parameters on the extraction recovery were investigated and optimized utilizing Plackett–Burman design and Box–Benken design, respectively. According to the Plackett–Burman design results, the volume of disperser solvent, extraction time, and stirring speed had no effect on the recovery of fluoxetine. The optimized conditions included a mixture of 172 μL of 1‐octanol as extraction solvent and 400 μL of methanol as disperser solvent, pH of 11.3 and 0% w/v of salt in the sample solution. Replicating the experiment in optimized condition for five times, gave the average extraction recoveries equal to 90.15%. The detection limit of fluoxetine in human plasma was obtained 3 ng/mL, and the linearity was in the range of 10–1200 ng/mL. The corresponding values for human urine were 4.2 ng/mL with the linearity range from 10 to 2000 ng/mL. Relative standard deviations for intra and inter day extraction of fluoxetine were less than 7% in five measurements. The developed method was successfully applied for the determination of fluoxetine in human plasma and urine samples.     

Application of ionic‐liquid‐supported magnetic dispersive solid‐phase microextraction for the determination of acaricides in fruit juice samples

In this study, ionic liquid (IL) supported magnetic dispersive solid‐phase microextraction was developed and a systematic investigation was conducted on imidazolium ILs for their extraction performance. This nano‐based pretreatment procedure was then applied for the determination of acaricides in fruit juice samples for the first time. A feature of this technique is that the commonly laborious chemical modification of magnetic nanoparticles (MNPs) was skillfully circumvented. Because of the combination of ILs, dispersive liquid–liquid microextraction, and dispersive MNP solid‐phase microextraction, the extraction efficiency can be significantly improved using commercial MNPs. Parameters of the extraction method were investigated by one‐factor‐at‐a‐time approach. The optimal experimental conditions were as follows: emulsification for 2 min by sonication with the addition of 50 μL [C₆MIM][NTf₂] in the dispersive liquid–liquid microextraction step and vortexing for 90 s after adding 40 mg spherical barium ferrite nanoparticles (20 nm). The desorption time was 2 min. Good linearity (0.5–500 ng/mL) and detection limits within the range of 0.05–0.53 ng/mL were achieved. The application of the proposed method was demonstrated by the analysis of real fruit juice samples, in which recoveries between 85.1 and 99.6% were obtained.     

New application of chitosan‐grafted polyaniline in dispersive solid‐phase extraction for the separation and determination of phthalate esters in milk using high‐performance liquid chromatography

Chitosan‐grafted polyaniline was synthesized and applied as a sorbent for the preconcentration of phthalate esters in dispersive solid‐phase extraction. By coupling dispersive solid‐phase extraction with high‐performance liquid chromatography and response surface methodology (central composite design), a reliable, sensitive, and cost‐effective method for simultaneous determination of phthalate esters including dimethyl phthalate, di‐n‐butyl phthalate, and di(2‐ethylhexyl)phthalate was developed. The morphology of sorbent had been studied by scanning electron microscopy and its chemical structure confirmed by Fourier transform infrared spectroscopy. Under optimum condition, good linearity was observed in the range of 5.0–5000.0 ng/mL. The limits of detection (S/N = 3) and limits of quantification (S/N = 10) were 0.1–0.3 and 0.3–1 ng/mL, respectively. The relative standard deviations were less than 8.8%. Finally, this procedure was employed for extraction of trace amounts of phthalic acid esters in milk samples, the relative recoveries ranged from 82 to 103%.     

Sensitive determination of methadone in human serum and urine by dispersive liquid–liquid microextraction based on the solidification of a floating organic droplet followed by HPLC–UV

Dispersive liquid–liquid microextraction based on solidification of floating organic droplet was developed for the extraction of methadone and determination by high‐performance liquid chromatography with UV detection. In this method, no microsyringe or fiber is required to support the organic microdrop due to the usage of an organic solvent with a low density and appropriate melting point. Furthermore, the extractant droplet can be collected easily by solidifying it at low temperature. 1‐Undecanol and methanol were chosen as extraction and disperser solvents, respectively. Parameters that influence extraction efficiency, i.e. volumes of extracting and dispersing solvents, pH, and salt effect, were optimized by using response surface methodology. Under optimal conditions, enrichment factor for methadone was 134 and 160 in serum and urine samples, respectively. The limit of detection was 3.34 ng/mmL in serum and 1.67 ng/mL in urine samples. Compared with the traditional dispersive liquid–liquid microextraction, the proposed method obtained lower limit of detection. Moreover, the solidification of floating organic solvent facilitated the phase transfer. And most importantly, it avoided using high‐density and toxic solvents of traditional dispersive liquid–liquid microextraction method. The proposed method was successfully applied to the determination of methadone in serum and urine samples of an addicted individual under methadone therapy.     

Optimization of multiwalled carbon nanotubes reinforced hollow‐fiber solid–liquid‐phase microextraction for the determination of polycyclic aromatic hydrocarbons in environmental water samples using experimental design

A novel design of hollow‐fiber liquid‐phase microextraction containing multiwalled carbon nanotubes as a solid sorbent, which is immobilized in the pore and lumen of hollow fiber by the sol–gel technique, was developed for the pre‐concentration and determination of polycyclic aromatic hydrocarbons in environmental water samples. The proposed method utilized both solid‐ and liquid‐phase microextraction media. Parameters that affect the extraction of polycyclic aromatic hydrocarbons were optimized in two successive steps as follows. Firstly, a methodology based on a quarter factorial design was used to choose the significant variables. Then, these significant factors were optimized utilizing central composite design. Under the optimized condition (extraction time = 25 min, amount of multiwalled carbon nanotubes = 78 mg, sample volume = 8 mL, and desorption time = 5 min), the calibration curves showed high linearity (R ² = 0.99) in the range of 0.01–500 ng/mL and the limits of detection were in the range of 0.007–1.47 ng/mL. The obtained extraction recoveries for 10 ng/mL of polycyclic aromatic hydrocarbons standard solution were in the range of 85–92%. Replicating the experiment under these conditions five times gave relative standard deviations lower than 6%. Finally, the method was successfully applied for pre‐concentration and determination of polycyclic aromatic hydrocarbons in environmental water samples.     

Novel mode of liquid‐phase microextraction: A magnetic stirrer as the extractant phase holder

In the present study, a novel configuration of liquid‐phase microextraction was proposed, in which a magnetic stirrer with a groove was used as the extractant phase holder. It was termed as magnetic stirrer liquid‐phase microextraction. In this way, the stability of the organic solvent was much improved under high stirring speed; the extraction efficiency was enhanced due to the enormously enlarged contact area between the organic solvent and aqueous phase. The extraction performance of the magnetic stirrer liquid‐phase microextraction was studied using chlorobenzenes as the probe analytes. A wide linearity range (20 pg/mL to 200 ng/mL) with a satisfactory linearity coefficient (r² > 0.998) was obtained. Limits of detection ranged from 9.0 to 12.0 pg/mL. Good reproducibility was achieved with intra‐ and inter‐day relative standard deviations <4.8%. The proposed magnetic stirrer liquid‐phase microextraction was simple, environmentally friendly and efficient; compared to single‐drop microextraction, it had obvious advantages in terms of reproducibility and extraction efficiency. It is a promising miniaturized liquid‐phase technology for real applications.