Dispersive solid‐phase extraction combined with dispersive liquid‐liquid microextraction for simultaneous determination of seven succinate dehydrogenase inhibitor fungicides in watermelon by ultra high performance liquid chromatography with tandem mass spectrometry

In this study, a simple and accurate sample preparation method based on dispersive solid‐phase extraction and dispersive liquid‐liquid microextraction has been developed for the determination of seven novel succinate dehydrogenase inhibitor fungicides (isopyrazam, fluopyram, pydiflumetofen, boscalid, penthiopyrad, fluxapyroxad, and thifluzamide) in watermelon. The watermelon samples were extracted with acetonitrile, cleaned up by dispersive solid‐phase extraction procedure using primary secondary amine, extracted and concentrated by the dispersive liquid‐liquid microextraction procedure with 1,1,2,2‐tetrachloroethane, and then analyzed by ultra high performance liquid chromatography with tandem mass spectrometry. The main experimental factors affecting the performance of dispersive solid‐phase extraction and dispersive liquid‐liquid microextraction procedure on extraction efficiency were investigated. The proposed method had a good linearity in the range of 0.1–100 µg/kg with correlation coefficients (r) of 0.9979–0.9999. The limit of quantification of seven fungicides was 0.1 µg/kg in the method. The fortified recoveries of seven succinate dehydrogenase inhibitor fungicides at three levels ranged from 72.0 to 111.6% with relative standard deviations of 3.4–14.1% (n = 5). The proposed method was successfully used for the rapid determination of seven succinate dehydrogenase inhibitor fungicides in watermelon.     

Development of a novel hollow‐fiber liquid‐phase microextraction based on oil‐in‐salt and its comparison with conventional one

A novel hollow‐fiber liquid‐phase microextraction based on oil‐in‐salt was proposed and introduced for the simultaneous extraction and enrichment of the main active compounds of hesperidin, honokiol, shikonin, magnolol, emodin, and β,β′‐dimethylacrylshikonin in a formula of Zi‐Cao‐Cheng‐Qi decoction and the single herb, Fructus Aurantii Immaturus , Cortex Magnoliae Officinalis , Radix et Rhizoma , and Lithospermum erythrorhizon , composing the formula prior to their analysis by high‐performance liquid chromatography. The results obtained by the proposed procedure were compared with those obtained by conventional hollow‐fiber liquid‐phase microextraction, and the proposed procedure mechanism was described. In the procedure, a hollow‐fiber segment was first immersed in organic solvent to fill the solvent in the fiber lumen and wall pore, and then the fiber was again immersed into sodium chloride solution to cover a thin salt membrane on the fiber wall pore filling organic solvent. Under the optimum conditions, the enrichment factors of the analytes were 0.6–109.4, linearities were 0.002–12 μg/mL with r ² ≥ 0.9950, detection limits were 0.6–12 ng/mL, respectively. The results showed that oil‐in‐salt hollow‐fiber liquid‐phase microextraction is a simple and effective sample pretreatment procedure and suitable for the simultaneous extraction and concentration of trace‐level active compounds in traditional Chinese medicine.     

Switchable‐hydrophilicity solvent liquid‐liquid microextraction versus dispersive liquid‐liquid microextraction prior to HPLC‐UV for the determination and isolation of piperine from Piper nigrum L

Switchable‐hydrophilicity solvent liquid‐liquid microextraction and dispersive liquid‐liquid microextraction were compared for the extraction of piperine from Piper nigrum L. prior to its analysis by using high‐performance liquid chromatography with UV detection. Under optimum conditions, limits of detection and quantitation were found as 0.2–0.6 and 0.7–2.0 μg/mg with the two methods, respectively. Calibration graphs showed good linearity with coefficients of determination (R²) higher than 0.9962 and percentage relative standard deviations lower than 6.8%. Both methods were efficiently used for the extraction of piperine from black and white pepper samples from different origins and percentage relative recoveries ranged between 90.0 and 106.0%. The results showed that switchable‐hydrophilicity solvent liquid‐liquid microextraction is a better alternative to dispersive liquid‐liquid microextraction for the routine analysis of piperine in food samples. A novel scaled‐up dispersive liquid‐liquid microextraction method was also proposed for the isolation of piperine providing a yield of 102.9 ± 4.9% and purity higher than 98.0% as revealed by NMR spectroscopy.     

Determination of 19 sulfonamides residues in pork samples by combining QuEChERS with dispersive liquid–liquid microextraction followed by UHPLC–MS/MS

A new simple and rapid pretreatment method for simultaneous determination of 19 sulfonamides in pork samples was developed through combining the QuEChERS method with dispersive liquid–liquid microextraction followed by ultra‐high performance liquid chromatography with tandem mass spectrometry. The sample preparation involves extraction/partitioning with QuEChERS method followed by dispersive liquid–liquid microextraction using tetrachloroethane as extractive solvent and the acetonitrile extract as dispersive solvent that obtained by QuEChERS. The enriched tetrachloroethane organic phase by dispersive liquid–liquid microextraction was evaporated, reconstituted with 100 μL acetonitrile/water (1:9 v/v) and injected into an ultra‐high performance liquid chromatography with a mobile phase composed of acetonitrile and 0.1% v/v formic acid under gradient elution and separated using a BHE C₁₈ column. Various parameters affecting the extraction efficiency were investigated. Matrix‐matched calibration curves were established. Good linear relationships were obtained for all analytes in a range of 2.0–100 μg/kg and the limits of detection were 0.04–0.49 μg/kg. Average recoveries at three spiking levels were in the range of 78.3–106.1% with relative standard deviations less than 12.7% (n = 6). The developed method was successfully applied to determine sulfonamide residues in pork samples.     

Extraction and determination of trace amounts of three anticancer pharmaceuticals in urine by three‐phase hollow fiber liquid‐phase microextraction based on two immiscible organic solvents followed by high‐performance liquid chromatography

An automated three‐phase hollow fiber liquid‐phase microextraction based on two immiscible organic solvents followed by high‐performance liquid chromatography with UV–Vis detection method was applied for the extraction and determination of exemestane, letrozole, and paclitaxel in water and urine samples. n‐Dodecane was selected as the supported liquid membrane and its polarity was justified by trioctylphosphine oxide. Acetonitrile was used as an organic acceptor phase with desirable immiscibility having n‐dodecane. All the effective parameters of the microextraction procedure such as type of the organic acceptor phase, the supported liquid membrane composition, extraction time, pH of the donor phase, hollow fiber length, stirring rate, and ionic strength were evaluated and optimized separately by a one variable at‐a‐time method. Under the optimal conditions, the linear dynamic ranges were 1.8–200 (R² = 0.9991), 0.9–200 (R² = 0.9987) and 1.2–200 μg/L (R² = 0.9983), and the limits of detection were 0.6, 0.3, and 0.4 μg/L for exemestane, letrozole, and paclitaxel, respectively. To evaluate the capability of the proposed method in the analysis of biological samples, three different urinary samples were analyzed under the optimal conditions. The relative recoveries of the three pharmaceuticals were in the range of 91–107.3% for these three analytes.     

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.     

Determination of N‐nitrosamines in cosmetic products by vortex‐assisted reversed‐phase dispersive liquid–liquid microextraction and liquid chromatography with mass spectrometry

A new analytical method for the simultaneous determination of trace levels of seven prohibited N‐nitrosamines (N‐nitrosodimethylamine, N‐nitrosoethylmethylamine, N‐nitrosopyrrolidine, N‐nitrosodiethylamine, N‐nitrosopiperidine, N‐nitrosomorpholine, and N‐nitrosodiethanolamine) in cosmetic products has been developed. The method is based on vortex‐assisted reversed‐phase dispersive liquid–liquid microextraction, which allows the extraction of highly polar compounds, followed by liquid chromatography with mass spectrometry. The variables involved in the extraction process were studied to obtain the highest enrichment factor. Under the selected conditions, 75 μL of water as extraction solvent was added to 5 mL of n‐hexane sample solution and assisted by vortex mixing during 30 s to form the cloudy solution. The method was successfully validated showing good linearity (0.5–50 ng/mL), enrichment factors up to 65 depending on the target compound, limits of detection values of 1.8–50 ng/g, and good repeatability (RSD < 9.8%). Finally, the proposed method was applied to different cosmetic samples. Quantitative relative recovery values (80–113%) were obtained, thus showing that matrix effects were negligible. The achieved analytical features of the proposed method, besides of its simplicity and affordability, make it useful to perform the quality control of cosmetic products to ensure the safety of consumers.     

Air‐assisted liquid–liquid extraction coupled with dispersive liquid–liquid microextraction and a drying step for extraction and preconcentration of some phthalate esters from edible oils prior to their determination by GC

In this work, a new, cheap, simple, fast, and low organic solvent consuming procedure is proposed for isolation, enrichment, and gas chromatographic determination of some phthalate esters in edible oils. The method is based on a combination of air‐assisted liquid–liquid extraction and dispersive liquid–liquid microextraction followed by a drying step under N₂ gas. Several experimental parameters affecting both extraction and preconcentration steps were investigated and optimized. Under the optimum conditions for the proposed method, wide linear ranges (0.05–800 μg/L) and low detection limits (0.007–0.023 μg/L) were observed. The ranges of enrichment factors and extraction recoveries were 68–340 and 14–68%, respectively. Eventually, the target analytes were successfully determined in different edible oils using the proposed method.     

Vortex‐assisted surfactant‐enhanced‐emulsification liquid–liquid microextraction of biogenic amines in fermented foods before their simultaneous analysis by high‐performance liquid chromatography

A simple, rapid, sensitive, and environmentally friendly method, based on modified dispersive liquid–liquid microextraction coupled with high‐performance liquid chromatography was developed for the simultaneous determination of five biogenic amines in fermented food samples. Biogenic amines were derivatized with 9‐fluorenylmethyl chloroformate, extracted by vortex‐assisted surfactant‐enhanced emulsification liquid–liquid microextraction, and then analyzed by high‐performance liquid chromatography. Five biogenic amine compounds were separated within 30 min using a C₁₈ column and gradient elution with acetonitrile and 1% acetic acid. Factors influencing the derivatization and extraction efficiency such as type and volume of extraction solvent, type, and concentration of surfactant, pH, salt addition, and vortex time were optimized. Under the optimum conditions, the method provided the enrichment factors in the range of 161–553. Good linearity was obtained from 0.002–0.5 mg/L for cadaverine and tyramine, 0.003–1 mg/L for tryptamine and histamine, and 0.005–1 mg/L for spermidine with coefficient of determination (R²) > 0.992. The limits of detection ranged from 0.0010 to 0.0026 mg/L. The proposed method was successfully applied to analysis of biogenic amines in fermented foods such as fermented fish (plaa‐som), wine and beer where good recoveries were obtained in the range of 83.2–112.5%     

Application of aeration‐assisted homogeneous liquid–liquid microextraction procedure using Box–Behnken design for determination of curcumin by HPLC

A simple, efficient, and rapid sample preparation method based on aeration‐assisted homogeneous liquid–liquid microextraction was developed for determination of curcumin in food samples by high‐performance liquid chromatography. The centrifuge step has been eliminated in this procedure. The effects of some variables, such as pH, volume of extraction solvent, extraction time, and salt effect, were studied through a Box–Behnken design method. Under the optimum conditions, calibration curves of curcumin were linear in the range of 0.08‐4000 μg/mL with R² = 0.997. Limit of detection and relative standard deviation were 0.019 μg/mL and 3.01%, respectively. The preconcentration factor achieved was 166. The proposed method was successfully applied to determination of curcumin in various food samples.     

Online solid‐phase extraction with high‐performance liquid chromatography and mass spectrometry for the determination of five tannins in traditional Chinese medicine injections

A rapid analytical method based on online solid‐phase extraction with high‐performance liquid chromatography and mass spectrometry has been established and applied to the determination of tannin compounds that may cause adverse effects in traditional Chinese medicine injections. Different solid‐phase extraction sorbents have been compared and the elution buffer was optimized. The performance of the method was verified by evaluation of recovery (≥40%), repeatability (RSD ≤ 6%), linearity (r² ≥ 0.993), and limit of quantification (≤0.35 μg/mL). Five tannin compounds, gallic acid, cianidanol, gallocatechin gallate, ellagic acid, and penta‐O‐galloylglucose, were identified with concentrations ranging from 3.1–37.4 μg/mL in the analyzed traditional Chinese medicine injections.     

Determination of triazine herbicides in juice samples by microwave‐assisted ionic liquid/ionic liquid dispersive liquid–liquid microextraction coupled with high‐performance liquid chromatography

A novel microextraction method, termed microwave‐assisted ionic liquid/ionic liquid dispersive liquid–liquid microextraction, has been developed for the rapid enrichment and analysis of triazine herbicides in fruit juice samples by high‐performance liquid chromatography. Instead of using hazardous organic solvents, two kinds of ionic liquids, a hydrophobic ionic liquid (1‐hexyl‐3‐methylimidazolium hexafluorophosphate) and a hydrophilic ionic liquid (1‐butyl‐3‐methylimidazolium tetrafluoroborate), were used as the extraction solvent and dispersion agent, respectively, in this method. The extraction procedure was induced by the formation of cloudy solution, which was composed of fine drops of 1‐hexyl‐3‐methylimidazolium hexafluorophosphate dispersed entirely into sample solution with the help of 1‐butyl‐3‐methylimidazolium tetrafluoroborate. In addition, an ion‐pairing agent (NH₄PF₆) was introduced to improve recoveries of the ionic liquid phase. Several experimental parameters that might affect the extraction efficiency were investigated. Under the optimum experimental conditions, the linearity for determining the analytes was in the range of 5.00–250.00 μg/L, with the correlation coefficients of 0.9982–0.9997. The practical application of this effective and green method is demonstrated by the successful analysis of triazine herbicides in four juice samples, with satisfactory recoveries (76.7–105.7%) and relative standard deviations (lower than 6.6%). In general, this method is fast, effective, and robust to determine triazine herbicides in juice samples.     

Dispersive liquid‐liquid microextraction coupled with pressure‐assisted electrokinetic injection for simultaneous enrichment of seven phenolic compounds in water samples followed by determination using capillary electrophoresis

Offline dispersive liquid‐liquid microextraction combined with online pressure‐assisted electrokinetic injection was developed to simultaneously enrich seven phenolic compounds in water samples, followed by determination using capillary electrophoresis, namely phenol, 4‐chlorophenol, pentachlorophenol, 2,4,6‐trichlorophenol, 2,4‐dichlorophenol, 2‐chlorophenol, and 2,6‐dichlorophenol. Several parameters affecting separation performance of capillary electrophoresis and the enrichment efficiency of pressure‐assisted electrokinetic injection and dispersive liquid‐liquid microextraction were systematically investigated. Under the optimal conditions, seven phenolic compounds were completely separated within 14 min and good enrichment factors were obtained of 61, 236, 3705, 3288, 920, 86, and 1807 for phenol, 4‐chlorophenol, pentachlorophenol, 2,4,6‐trichlorophenol, 2,4‐dichlorophenol, 2‐chlorophenol, and 2,6‐dichlorophenol, respectively. Good linearity was attained in the range of 0.1–200 μg/L for 2,4‐dichlorophenol, 0.5–200 μg/L for 4‐chlorophenol, pentachlorophenol, 2,4,6‐trichlorophenol, 2‐chlorophenol, and 2,6‐dichlorophenol, as well as 1–200 μg/L for phenol, with correlation coefficients (r) over 0.9905. The limits of detection and quantification ranging from 0.03–0.28 and 0.07–0.94 μg/L were attained. This two step enrichment method was potentially applicable for the rapid and simultaneous determination of phenolic compounds in water samples.     

Three‐phase solvent bar liquid‐phase microextraction combined with high‐performance liquid chromatography to determine sarcosine in human urine

Sarcosine is a potential prostate cancer marker. In this study, we developed a method of three‐phase solvent bar liquid‐phase microextraction combined with high‐performance liquid chromatography to determine sarcosine after derivatization with 4‐dimethylarminoazobenzene‐4‐sulfonyl chloride from human urine. The effects of different extraction conditions on extraction efficiency were investigated and optimized. Under optimum experimental conditions, a calibration graph exhibited linearity over the range of 0.05–25 μmol/L with a correlation coefficient (r²) of 0.9990. The enrichment factor was 168, and the detection limit was 0.02 μmol/L. The method was successfully used to analyze sarcosine in human urine and non‐invasive detection, and good spiked recoveries ranging from 90.5 to 93.6% were obtained. The proposed method exhibited high sensitivity, high enrichment factor, good precision, and a simple setup. It may contribute to the early accurate diagnosis and the progression monitoring of prostatic carcinoma.     

Simple and rapid determination of zaltoprofen in human plasma by manual‐shaking‐assisted dispersive liquid–liquid microextraction followed by liquid chromatography with ultraviolet detection

A readily applicable method was developed to determine the concentration level of zaltoprofen, a non‐steroidal antiinflammatory drug from the propionic acid family, in human plasma. This method is based on manual‐shaking‐assisted dispersive liquid–liquid microextraction coupled with liquid chromatography with ultraviolet detection. Factors affecting the extraction efficiency were screened and optimized by experimental design using fractional factorial and central composite designs, respectively. Optimal conditions were: 220 μL of C₂H₄Cl₂ (extraction solvent), 5 mL of 3.75% w/v NaCl aqueous solution at pH 2.0, and manual shaking for 13 s (65 times). The resulting extraction method yielded a reasonable enrichment factor of 18.0 (±0.6, n  = 3) and extraction recovery of 86.0% (±3.3%, n  = 3). The established method was validated for selectivity, linearity, precision, accuracy, matrix effect, recovery, dilution integrity, and stability, and it met the acceptable criteria for all of the tested parameters. Specifically, the method was linear in the range of 0.16–50.0 mg/L, precise (< 8.8% RSD), accurate (–7.5–5.6% deviation), and showed negligible matrix effects (96.1–106.4%) with high absolute recovery (94.5–97.7%). Compared with previous methods involving labor‐intensive liquid–liquid extraction or non‐specific protein precipitation, our method allows the simple, rapid, and efficient determination of zaltoprofen using the most affordable analytical instrument, liquid chromatography with ultraviolet detection.     

Ion‐pair switchable‐hydrophilicity solvent‐based homogeneous liquid–liquid microextraction for the determination of paraquat in environmental and biological samples before high‐performance liquid chromatography

An approach involving ion‐pair switchable‐hydrophilicity solvent‐based homogeneous liquid–liquid microextraction coupled to high‐performance liquid chromatography has been applied for the preconcentration and separation of paraquat in a real sample. A mixture of triethylamine and water was used as the switchable‐hydrophilicity solvent. The pH was regulated using carbon dioxide; hence the ratio of the ionized and non‐ionized form of triethylamine could control the optimum conditions. Sodium dodecyl sulfate was utilized as an ion‐pairing agent. The ion‐associate complex formed between the cationic paraquat and sodium dodecyl sulfate was extracted into triethylamine. The separation of the two phases was carried out by the addition of sodium hydroxide, which changed the ionization state of triethylamine. The effects of some important parameters on the extraction recovery were investigated. Under the optimum conditions (500 μL of the extraction solvent, 1 mg sodium dodecyl sulfate, 2.0 mL of 10 mol/L sodium hydroxide, and pH 4), the limit of detection and the limit of quantification were 0.2 and 0.5 μg/L, respectively, with preconcentration factor of 74. The precision (RSD, n  = 10) was  <5%. The recovery of the analyte in environmental and biological samples was in the range of 90.0–92.3%.     

Evaluation of two membrane‐based microextraction techniques for the determination of endocrine disruptors in aqueous samples by HPLC with diode array detection

In this study, the viability of two membrane‐based microextraction techniques for the determination of endocrine disruptors by high‐performance liquid chromatography with diode array detection was evaluated: hollow fiber microporous membrane liquid–liquid extraction and hollow‐fiber‐supported dispersive liquid–liquid microextraction. The extraction efficiencies obtained for methylparaben, ethylparaben, bisphenol A, benzophenone, and 2‐ethylhexyl‐4‐methoxycinnamate from aqueous matrices obtained using both approaches were compared and showed that hollow fiber microporous membrane liquid–liquid extraction exhibited higher extraction efficiency for most of the compounds studied. Therefore, a detailed optimization of the extraction procedure was carried out with this technique. The optimization of the extraction conditions and liquid desorption were performed by univariate analysis. The optimal conditions for the method were supported liquid membrane with 1‐octanol for 10 s, sample pH 7, addition of 15% w/v of NaCl, extraction time of 30 min, and liquid desorption in 150 μL of acetonitrile/methanol (50:50 v/v) for 5 min. The linear correlation coefficients were higher than 0.9936. The limits of detection were 0.5–4.6 μg/L and the limits of quantification were 2–16 μg/L. The analyte relative recoveries were 67–116%, and the relative standard deviations were less than 15.5%.     

Vortex‐assisted liquid–liquid microextraction using a low‐toxicity solvent for the determination of five organophosphorus pesticides in water samples by high‐performance liquid chromatography

Vortex‐assisted liquid–liquid microextraction followed by high‐performance liquid chromatography with UV detection was applied to determine Isocarbophos, Parathion‐methyl, Triazophos, Phoxim and Chlorpyrifos‐methyl in water samples. 1‐Bromobutane was used as the extraction solvent, which has a higher density than water and low toxicity. Centrifugation and disperser solvent were not required in this microextraction procedure. The optimum extraction conditions for 15 mL water sample were: pH of the sample solution, 5; volume of the extraction solvent, 80 μL; vortex time, 2 min; salt addition, 0.5 g. Under the optimum conditions, enrichment factors ranging from 196 to 237 and limits of detection below 0.38 μg/L were obtained for the determination of target pesticides in water. Good linearities (r > 0.9992) were obtained within the range of 1–500 μg/L for all the compounds. The relative standard deviations were in the range of 1.62–2.86% and the recoveries of spiked samples ranged from 89.80 to 104.20%. The whole proposed methodology is simple, rapid, sensitive and environmentally friendly for determining traces of organophosphorus pesticides in the water samples.     

Ion‐pair‐based hollow‐fiber liquid‐phase microextraction combined with high‐performance liquid chromatography for the simultaneous determination of urinary benzene,toluene, and styrene metabolites

In the current study, a novel technique for extraction and determination of trans,trans‐muconic acid, hippuric acid, and mandelic acid was developed by means of ion‐pair‐based hollow fiber liquid‐phase microextraction in the three‐phase mode. Important factors affecting the extraction efficiency of the method were investigated and optimized. These metabolites were extracted from 10 mL of the source phase into a supported liquid membrane containing 1‐octanol and 10% w/v of Aliquat 336 as the ionic carrier followed by high‐performance liquid chromatography analysis. The organic phase immobilized in the pores of a hollow fiber was back‐extracted into 24 μL of a solution containing 3.0 mol/L sodium chloride placed inside the lumen of the fiber. A very high preconcentration of 212‐ to 440‐fold, limit of detection of 0.1–7 μg/L, and relative recovery of 87–95% were obtained under the optimized conditions of this method. The relative standard deviation values for within‐day and between‐day precisions were calculated at 2.9–8.5 and 4.3–11.2%, respectively. The method was successfully applied to urine samples from volunteers at different work environments. The results demonstrated that the method can be used as a sensitive and effective technique for the determination of the metabolites in urine.     

Preparation of magnetic mesoporous silica composite for the solid‐phase microextraction of diazinon and malathion before their determination by high‐performance liquid chromatography

A novel magnetic mesoporous silica material was synthesized and used as the sorbent for the magnetic solid‐phase microextraction of diazinon and malathion before their quantification by high‐performance liquid chromatography with UV detection. The sorbent was synthesized by a surfactant‐templated one‐pot sol–gel procedure using SiO₂‐coated Fe₃O₄ as the magnetic support, cetyltrimethylammonium bromide as the template and tetraethyl orthosilicate as the silicon source. The characteristics of the prepared sorbent were investigated using Fourier transform infrared spectroscopy, scanning electron microscopy, and X‐ray diffraction. The sorbent exhibited a high maximum adsorption capacity of 19.2 and 9.4 mg/g for diazinon and malathion, respectively. The parameters affecting the microextraction were optimized by the MultiSimplex method. Under the optimized conditions, the calibration graphs were linear in the concentration ranges of 0.3–50.0 and 0.5–50 μg/L with the limits of detection of 0.09 and 0.14 μg/L for diazinon and malathion, respectively. The relative standard deviations (n = 5) at a concentration level of 10.0 μg/L of analytes were less than 2.5 and 4% for intra and interday, respectively. The developed method was successfully used for the determination of diazinon and malathion in apple, tomato, cucumber, tap water, and well water samples.