Sulfonated poly(styrene‐divinylbenzene) modified with amines and the application for pipette‐tip solid‐phase extraction of carbendazim in apples

Sulfonated poly(styrene‐divinylbenzene) modified with five kinds of amine functional groups was applied to the determination of carbendazim in apple samples with a pipette‐tip solid‐phase extraction method. The structures of the polymers were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. Five different modifications of the solid‐phase extraction sorbent based on sulfonated poly(styrene‐divinylbenzene) were tested under static and pipette‐tip solid‐phase extraction conditions. The polymer modified with p‐methoxyaniline showed the best recognition capacity and adsorption amount for carbendazim. Under the optimum conditions, 3.00 mg of the adsorbent, 1.00 mL of ethyl acetate as washing solvent, and 1.00 mL of ammonia/acetonitrile (5:95, v/v) as elution solvent were used in the pretreatment procedure of apple samples. The calibration graphs of carbendazim in methanol were linear over 5.00–200.00 μg/mL, and the limits of detection and quantification were 0.01 and 0.03 μg/mL, respectively. The method recoveries of carbendazim were in the range of 91.31–98.13% with associated intraday relative standard deviations of 0.76–2.13% and interday relative standard deviations of 1.10–1.85%. Sulfonated poly(styrene‐divinylbenzene) modified with p‐methoxyaniline showed satisfactory results (recovery: 97.96%) and potential for the rapid purification of carbendazim in apple samples combined with the pipette‐tip solid‐phase extraction.     

Pipette‐tip solid‐phase extraction based on deep eutectic solvent modified graphene for the determination of sulfamerazine in river water

A green and novel deep eutectic solvent modified graphene was prepared and used as a neutral adsorbent for the rapid determination of sulfamerazine in a river water sample by pipette‐tip solid‐phase extraction. Compared with conventional graphene, deep eutectic solvent modified graphene can change the surface of graphene with wrinkled structure and higher selective extraction ability. The properties of deep eutectic solvent modified graphene and graphene were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. Static adsorption showed deep eutectic solvent modified graphene had a higher adsorption ability (18.62 mg/g) than graphene. Under the optimum conditions, factors such as kinds of washing solvents and elution solvents and volume of elution solvent were evaluated. The limits of detection and quantification were 0.01 and 0.03 μg/mL, respectively. The method recoveries of sulfamerazine were in the range of 91.01–96.82% with associated intraday relative standard deviations ranging from 1.63 to 3.46% and interday relative standard deviations ranging from 0.68 to 3.84%. Deep eutectic solvent modified graphene showed satisfactory results (recovery was 95.38%) and potential for rapid purification of sulfamerazine in river water sample in combination with the pipette‐tip solid‐phase extraction method.     

Development of coupled ultrasound‐assisted and reversed‐phase dispersive liquid–liquid microextraction before high‐performance liquid chromatography for the sensitive determination of vitamin A and vitamin E in oil samples

A new approach based on the ultrasound‐assisted reversed‐phase dispersive liquid–liquid microextraction technique is developed for the extraction and determination of vitamin A and vitamin E from oil matrices before high‐performance liquid chromatography analysis. A methodology based on the full factorial design is carried out to choose the significant parameters. Then the significant factors affecting the extraction efficiency including pH, volume of extraction solvent, and volume of disperser solvent are optimized using a Box–Behnken design. After analyzing the results obtained, the optimum conditions were: pH 4.5, 80–20 μL of the ethanol/water solvent mixture as extraction solvent, 110 μL of 1,4‐dioxane as the disperser solvent, and a sonication time of 10 min. For validation of the developed method, the linear dynamic range, repeatability, limit of detection, and recoveries were obtained under the optimum conditions. The detection limits of the method were 1.6 and 2.3 ng/mL for vitamin A and vitamin E, respectively. The extraction recovery percentages for the studied drugs were above 91%, with acceptable relative standard deviation. The proposed methodology was successfully applied for the determination of the vitamins in different oil samples.     

Covalently bonded aptamer‐functionalised magnetic mesoporous carbon for high‐efficiency chloramphenicol detection

A novel aptamer‐modified magnetic mesoporous carbon was prepared to develop a specific and sensitive magnetic solid‐phase extraction method through combination with ultra‐high performance liquid chromatography‐tandem mass spectrometry for the analysis chloramphenicol in complex samples. More specifically, the chloramphenicol aptamer‐modified Mg/Al layered double hydroxide magnetic mesoporous carbon was employed as a novel magnetic solid‐phase extraction sorbent for analyte enrichment and sample clean‐up. The extraction solvent, extraction time, desorption solvent, and desorption time were investigated. It was found that the mesoporous structure and aptamer‐based affinity interactions resulted in acceptable selective recognition and a good chemical stability toward trace amounts of chloramphenicol. Upon combination with the ultra‐high performance liquid chromatography‐tandem mass spectrometry technique, a specific and sensitive recognition method was developed with a low limit of detection (0.94 pmol/L, S/N = 3) for chloramphenicol analysis. The developed method was successfully employed for the determination of chloramphenicol in complex serum, milk powders, fish and chicken samples, giving recoveries of 87.0‐107% with relative standard deviations of 3.1‐9.7%.     

A rapid MCM‐41 dispersive micro‐solid phase extraction coupled with LC/MS/MS for quantification of ketoconazole and voriconazole in biological fluids

A rapid dispersive micro‐solid phase extraction (D‐μ‐SPE) combined with LC/MS/MS method was developed and validated for the determination of ketoconazole and voriconazole in human urine and plasma samples. Synthesized mesoporous silica MCM‐41 was used as sorbent in d ‐μ‐SPE of the azole compounds from biological fluids. Important D‐μ‐SPE parameters, namely type desorption solvent, extraction time, sample pH, salt addition, desorption time, amount of sorbent and sample volume were optimized. Liquid chromatographic separations were carried out on a Zorbax SB‐C₁₈ column (2.1 × 100 mm, 3.5 μm), using a mobile phase of acetonitrile–0.05% formic acid in 5 mm ammonium acetate buffer (70:30, v /v). A triple quadrupole mass spectrometer with positive ionization mode was used for the determination of target analytes. Under the optimized conditions, the calibration curves showed good linearity in the range of 0.1–10,000 μg/L with satisfactory limit of detection (≤0.06 μg/L) and limit of quantitation (≤0.3 μg/L). The proposed method also showed acceptable intra‐ and inter‐day precisions for ketoconazole and voriconazole from urine and human plasma with RSD ≤16.5% and good relative recoveries in the range 84.3–114.8%. The MCM‐41‐D‐μ‐SPE method proved to be rapid and simple and requires a small volume of organic solvent (200 μL); thus it is advantageous for routine drug analysis.     

Dispersive micro‐solid‐phase extraction of benzoylurea insecticides in honey samples with a β‐cyclodextrin‐modified attapulgite composite as sorbent

A β‐cyclodextrin‐modified attapulgite composite was prepared and used as a dispersive micro‐solid‐phase extraction sorbent for the determination of benzoylurea insecticides in honey samples. Parameters that may influence the extraction efficiency, such as the type and volume of the eluent, the amount of the sorbent, the extraction time and the ionic strength were investigated and optimized using batch and column procedures. Under optimized conditions, good linearity was obtained for all of the tested compounds, with R² values of at least 0.9834. The limits of detection were determined in the range of 0.2–1.0 μg/L. The recoveries of the four benzoylurea insecticides in vitex honey and acacia honey increased from 15.2 to 81.4% and from 14.2 to 82.0%, respectively. Although the β‐cyclodextrin‐modified attapulgite composite did not show a brilliant adsorption capacity for the selected benzoylurea insecticides, it exhibited a higher adsorption capacity toward relatively hydrophobic compounds, such as chlorfluazuron and hexaflumuron (recoveries in vitex honey samples ranged from 70.0 to 81.4% with a precision of 1.0–3.7%). It seemed that the logP_ow of the benzoylurea insecticides is related to their recoveries. The results confirmed the possibility of using cyclodextrin‐modified palygorskite in the determination of relatively hydrophobic trace pharmaceutical residues.     

Surfactant‐assisted dispersive liquid–liquid microextraction of nitrazepam and lorazepam from plasma and urine samples followed by high‐performance liquid chromatography with UV analysis

Surfactant‐assisted liquid–liquid microextraction followed by high‐performance liquid chromatography with UV detection has been developed for the simultaneous preconcentration and determination of lorazepam and nitrazepam in biological fluids. In this study, an ionic surfactant (cetyltrimethyl ammonium bromide) was used as an emulsifier. The predominant parameters affecting extraction efficiency such as the type and volume of extraction solvent, the type and concentration of surfactant, sample pH, and the concentration of salt added to the sample were investigated and opted. Under the optimum conditions (extraction solvent and its volume, 1‐octanol, 70 μL; surfactant and its concentration, 1 mL of ultra‐pure water containing 2 mmol L^?1 cetyltrimethyl ammonium bromide; sample pH = 9 and salt content of 10% NaCl w/v), the preconcentration factors were obtained in the range of 202–241 and 246–265 for nitrazepam and lorazepam, respectively. The limits of quantification for both drugs were 5 μg L^?1 in water sample and 10 μg L^?1 in biological fluids with R² values higher than 0.993. The suitability of the proposed method was successfully confirmed by the extraction and determination of the target drugs in human urine and plasma samples in the range of microgram per liter.     

Ultrapreconcentration and determination of organophosphorus pesticides in water by solid‐phase extraction combined with dispersive liquid–liquid microextraction and high‐performance liquid chromatography

Solid‐phase extraction coupled with dispersive liquid–liquid microextraction was developed as an ultra‐preconcentration method for the determination of four organophosphorus pesticides (isocarbophos, parathion‐methyl, triazophos and fenitrothion) in water samples. The analytes considered in this study were rapidly extracted and concentrated from large volumes of aqueous solutions (100 mL) by solid‐phase extraction coupled with dispersive liquid–liquid microextraction and then analyzed using high performance liquid chromatography. Experimental variables including type and volume of elution solvent, volume and flow rate of sample solution, salt concentration, type and volume of extraction solvent and sample solution pH were investigated for the solid‐phase extraction coupled with dispersive liquid–liquid microextraction with these analytes, and the best results were obtained using methanol as eluent and ethylene chloride as extraction solvent. Under the optimal conditions, an exhaustive extraction for four analytes (recoveries >86.9%) and high enrichment factors were attained. The limits of detection were between 0.021 and 0.15 μg/L. The relative standard deviations for 0.5 μg/L of the pesticides in water were in the range of 1.9–6.8% (n = 5). The proposed strategy offered the advantages of simple operation, high enrichment factor and sensitivity and was successfully applied to the determination of four organophosphorus pesticides in water samples.     

Functionalized nanoparticles based solid‐phase membrane micro‐tip extraction and high‐performance liquid chromatography analyses of vitamin B complex in human plasma

Iron nanoparticles were prepared by a green method following functionalization using 1‐butyl‐3‐methylimidazolium bromide. 1‐Butyl‐3‐methylimidazole iron nanoparticles were characterized using FTIR spectroscopy, energy dispersive X‐ray fluorescence, X‐ray diffraction, scanning electron microscopy and transmission electron microscopy. The nanoparticles were used in solid‐phase membrane micro‐tip extraction to separate vitamin B complex from plasma before high‐performance liquid chromatography. The optimum conditions obtained were sorbent (15 mg), agitation time (30 min), pH (9.0), desorbing solvent [water (5 mL) + methanol (5 mL) + sodium hydroxide (0.1 N) + acetic acid (d = 1.05 kg/L, pH 5.5), desorbing volume (10 mL) and desorption time (30 min). The percentage recoveries of all the eight vitamin B complex were from 60 to 83%. A high‐performance liquid chromatography method was developed using a PhE column (250 × 4.6 mm, 5.0 μm) and water/acetonitrile (95:5, v/v; pH 4.0 with 0.1% formic acid) mobile phase. The flow rate was 1.0 mL/min with detection at 270 and 210 nm. The values of the capacity, separation and resolution factor were 0.57–39.47, 1.12–6.00 and 1.84–26.26, respectively. The developed sample preparation and chromatographic methods were fast, selective, inexpensive, economic and reproducible. The developed method can be applied for analyzing these drugs in biological and environmental matrices.     

Development and validation of automated SPE‐LC‐MS/MS method for determination of indapamide in human whole blood and its application to real study samples

A fast and simple liquid chromatography–electrospray ionization tandem mass spectrometry method for determination of indapamide in human whole blood was developed and validated. The sample extraction of indapamide from human whole blood was achieved using automated solid‐phase extraction. Chromatographic separation was performed on Kinetex C₁₈ column (100 × 2.1 mm, 1.7 µm particle size) using acetonitrile and 2 mm ammonium formate in ratio 90:10 (v/v) as a mobile phase. The mass spectrometer was operated in the multiple reaction monitoring mode using positive electrospray ionization for indapamide and the internal standard (zolpidem tartarate). The total run time was 2.5 min. The present method was found to be linear in the concentration range of 1–50 ng/mL with the coefficient of determination 0.9987. The absolute recoveries of indapamide were 90.51–93.90%. The method was validated according the recommendations for validation of bioanalytical methods of European Medicines Agency guideline and was successfully used to analyze human whole blood samples for application in a pharmacokinetic study. Copyright © 2013 John Wiley & Sons, Ltd.     

Sensitive determination of three aconitum alkaloids and their metabolites in human plasma by matrix solid‐phase dispersion with vortex‐assisted dispersive liquid–liquid microextraction and HPLC with diode array detection

A simple and sensitive method for determination of three aconitum alkaloids and their metabolites in human plasma was developed using matrix solid‐phase dispersion combined with vortex‐assisted dispersive liquid–liquid microextraction and high‐performance liquid chromatography with diode array detection. The plasma sample was directly purified by matrix solid‐phase dispersion and the eluate obtained was concentrated and further clarified by vortex‐assisted dispersive liquid–liquid microextraction. Some important parameters affecting the extraction efficiency, such as type and amount of dispersing sorbent, type and volume of elution solvent, type and volume of extraction solvent, salt concentration as well as sample solution pH, were investigated in detail. Under optimal conditions, the proposed method has good repeatability and reproducibility with intraday and interday relative standard deviations lower than 5.44 and 5.75%, respectively. The recoveries of the aconitum alkaloids ranged from 73.81 to 101.82%, and the detection limits were achieved within the range of 1.6–2.1 ng/mL. The proposed method offered the advantages of good applicability, sensitivity, simplicity, and feasibility, which makes it suitable for the determination of trace amounts of aconitum alkaloids in human plasma samples.     

Magnetic nanocomposite of self‐doped polyaniline–graphene as a novel sorbent for solid‐phase extraction

This work is the first study on the extraction efficiency of self‐doped polyaniline that is immobilized on the graphene‐modified magnetic nanoparticles. The new material was used as a sorbent for the magnetic solid‐phase extraction of methyl‐, propyl‐, and butylparabens. The use of graphene provides a high surface area and prevents aggregation of the nanoparticles. The self‐doped polyaniline also provides multifunctionality, high extraction capacity, and chemical stability even in the basic medium. The parabens were acetylated for determination by gas chromatography with flame ionization detection. The effects of monomer ratio, extraction solvent, sorbent amount, sample volume, desorption solvent volume, adsorption and desorption times, and sample ionic strength were optimized. Preconcentration factors obtained were from 190 to 310. The detection limits of the method were <2.8 μg/L. Linear ranges of the method were 5–2000 μg/L for propyl and butyl parabens, and 10–2000 μg/L for methyl paraben. The method was applied for the determination of the parabens in cosmetic products and extraction recoveries were 89–101% with RSDs ≤7.9%.     

Extraction and determination of flavonoids in fruit juices and vegetables using Fe3O4/SiO2 magnetic nanoparticles modified with mixed hemi/ad‐micelle cetyltrimethylammonium bromide and high performance liquid chromatography

Extraction and determination of three flavonoids (morin, quercetin, and kaempferol) were performed by dispersive magnetic solid phase extraction based on mixed hemi/ad‐micelles and high‐performance liquid chromatography with UV detection. The Fe₃O₄/SiO₂ nanoparticles were synthesized and characterized by X‐ray diffraction, FTIR, scanning electron microscopy, and thermogravimetric analysis. Fe₃O₄/SiO₂ nanoparticles coated with mixed hemi/ad‐micelles cetyltrimethyl ammonium bromide was applied as a sorbent and used for extraction of flavonoids. Effective parameters on the extraction recovery such as amount of magnetic nano particles, volume of cetyltrimethyl ammonium bromide solution with specific concentration, pH of sample solution, adsorption equilibrium time, volume of desorption solvent, and desorption times were evaluated and optimized using fractional factorial design and central composite design. Under the optimum condition limit of detection and linearity were 0.83, 2.7–500.0 for morin, 0.18, 0.7–500.0 for quercetin and, 0.37, 1.3–500.0 µg/L for kaempferol. The extraction recovery with relative standard deviation were 97.88, 1.94 for morin, 95.77, 0.80 for quercetin, and 93.35, 1.45 for kaempferol. The proposed method was applied for simultaneous extraction and determination of flavonoids in several fruit juices and vegetable samples.     

Hydrophilic solid‐phase extraction of melamine with ampholine‐modified hybrid organic–inorganic silica material

In this work, an ampholine‐functionalized hybrid organic–inorganic silica sorbent was successfully used to extract melamine from a milk formula sample by a hydrophilic interaction solid‐phase extraction protocol. Primary factors affecting the extraction efficiency of the material such as extraction solvent, elution solvent, sample loading volume, and elution volume have been thoroughly optimized. Under the optimized hydrophilic solid‐phase extraction conditions, the recoveries of melamine spiked in milk formula samples ranged from 86.2 to 101.8% with relative standard deviations of 4.1–9.4% (n = 3). The limit of detection (S/N = 3) was 0.32 μg/g. The adsorption capacity toward melamine was 30 μg of melamine per grams of sorbent. Due to its simplicity, rapidity and cost effectiveness, the newly developed hydrophilic solid‐phase extraction method should provide a promising tool for daily monitoring of doped melamine in milk formula.     

Ionic‐liquid‐functionalized zinc oxide nanoparticles for the solid‐phase extraction of triazine herbicides in corn prior to high‐performance liquid chromatography analysis

Zinc oxide nanoparticles have recently been used as effective adsorbent materials for sample pretreatment in analytical chemistry because of their excellent properties, such as high specific surface area, high effective porosity, non‐toxicity, and ease of fabrication. In this study, the zinc oxide nanoparticles functionalized by an ionic liquid, 1‐carboxyethyl‐3‐methylimidazolium chloride, were fabricated and used as the adsorbent for the solid phase extraction of five triazine herbicides in corn for the first time. High‐performance liquid chromatography was employed for the determination of these triazine herbicides. Several experimental parameters affecting the extraction efficiency were investigated, including the volume of extraction solvent, the extraction time, the type of extraction solvent and elution solvent, the amount of absorbent, and the volume of elution solvent. By using the proposed method, low limits of detection and quantification for all the five triazine herbicides were obtained between 0.71–1.08 and 2.67–3.64 ng/g, respectively. Recoveries of the proposed method range from 89.05 to 100.33% with intra‐ and inter‐day relative standard deviations lower than 8.45%. The calibration curves are linear in the concentration range of 0.005–1.00 μg/g with the correlation coefficient higher than 0.9954.     

Determination of zearalenone in maize products by vortex‐assisted ionic‐liquid‐based dispersive liquid–liquid microextraction with high‐performance liquid chromatography

A novel method has been developed for the analysis of zearalenone in maize products by vortex‐assisted ionic‐liquid‐based dispersive liquid–liquid microextraction combined with HPLC and fluorescence detection. Maize samples were extracted with methanol/water (80:20, v/v) and the extraction solution was then used as the dispersive solvent in the microextraction procedure. The analyte was rapidly transmitted to a small volume of ionic liquid and was determined by HPLC. Various parameters affecting the recovery of the mycotoxin were investigated, such as the type and volume of the extraction solvent, the type and volume of the dispersive solvent, the pH of the aqueous phase, the salt addition, and the time of vortex and centrifugation. Under the optimal experimental conditions, a good linearity of the analyte was obtained in the range of 1.0–1000.0 μg/L with the correlation coefficient of 0.9998. The limit of detection (S/N = 3) and quantification (S/N = 10) were 0.3 and 1.0 μg/kg, and the mean recoveries ranged from 83.5 to 94.9%, with a relative standard deviation less than 5.0%. The proposed method was demonstrated to be simple, cheap, quick, and highly selective and was successfully applied to the determination of zearalenone in maize products.     

Ion‐pair cloud‐point extraction: A new method for the determination of water‐soluble vitamins in plasma and urine

A novel, simple, and effective ion‐pair cloud‐point extraction coupled with a gradient high‐performance liquid chromatography method was developed for determination of thiamine (vitamin B₁), niacinamide (vitamin B₃), pyridoxine (vitamin B₆), and riboflavin (vitamin B₂) in plasma and urine samples. The extraction and separation of vitamins were achieved based on an ion‐pair formation approach between these ionizable analytes and 1‐heptanesulfonic acid sodium salt as an ion‐pairing agent. Influential variables on the ion‐pair cloud‐point extraction efficiency, such as the ion‐pairing agent concentration, ionic strength, pH, volume of Triton X‐100, extraction temperature, and incubation time have been fully evaluated and optimized. Water‐soluble vitamins were successfully extracted by 1‐heptanesulfonic acid sodium salt (0.2% w/v) as ion‐pairing agent with Triton X‐100 (4% w/v) as surfactant phase at 50°C for 10 min. The calibration curves showed good linearity (r² > 0.9916) and precision in the concentration ranges of 1‐50 μg/mL for thiamine and niacinamide, 5–100 μg/mL for pyridoxine, and 0.5–20 μg/mL for riboflavin. The recoveries were in the range of 78.0–88.0% with relative standard deviations ranging from 6.2 to 8.2%.     

Ultra‐trace analysis of furanic compounds in transformer/rectifier oils with water extraction and high‐performance liquid chromatography

A novel approach for the determination of parts‐per‐billion level of 5‐hydroxymethyl‐2‐furaldehyde, furfuryl alcohol, furfural, 2‐furyl methyl ketone, and 5‐methylfurfural in transformer or rectifier oils has been successfully innovated and implemented. Various extraction methods including solid‐phase extraction, liquid–liquid extraction using methanol, acetonitrile, and water were studied. Water was by far the most efficient solvent for use as an extraction medium. Separation of the analytes was conducted using a 4.6 mm × 250 mm × 3.5 μm Agilent Zorbax column while detection and quantitation were conducted with a variable wavelength UV detector. Detection limits of all furans were at 1 ppb v/v with linear ranges range from 5 to 1000 ppb v/v with correlation coefficients of 0.997 or better. A relative standard deviation of at most 2.4% at 1000 ppb v/v and 7.3% at 5 ppb v/v and a recovery from 43% to 90% depending on the analyte monitored were obtained. The method was purposely designed to be environmental friendly with water as an extraction medium. Also, the method uses 80% water and 20% acetonitrile with a mere 0.2 mL/min of acetonitrile in an acetonitrile/water mixture as mobile phase. The analytical technique has been demonstrated to be highly reliable with low cost of ownership, suitable for deployment in quality control labs or in regions where available analytical resources and solvents are difficult to procure.     

Solid‐phase nanoextraction of polychlorinated biphenyls in water and their determination by gas chromatography with electron capture detector

A solid‐phase nanoextraction method has been developed for the extraction and preconcentration of polychlorinated biphenyls using carboxyl multiwalled carbon nanotubes as a solid nano‐sorbent. Parameters affecting extraction efficiency such as sorbent amount, desorption solvent type and volume, extraction time, pH, and salt content have been studied. Under optimized conditions, the correlation coefficient was up to 0.9989, the limits of detection was in the range of 1.4–3.5 ng/L, and limits of quantification was between 4.8 and 11.6 ng/L. The recoveries were in the range of 99–106% for different spiked analytes. The relative standard deviation for water samples spiked with two different spiking levels has been between 4 and 10%. The proposed sustainable method is rapid, easy to use, and small consumption of organic solvent for the detection and determination of trace levels of polychlorinated biphenyls in environmental waters.     

Polypyrrole‐magnetite dispersive micro‐solid‐phase extraction combined with ultraviolet‐visible spectrophotometry for the determination of rhodamine 6G and crystal violet in textile wastewater

Polypyrrole‐magnetite dispersive micro‐solid‐phase extraction method combined with ultraviolet‐visible spectrophotometry was developed for the determination of selected cationic dyes in textile wastewater. Polypyrrole‐magnetite was used as adsorbent due to its thermal stability, magnetic properties, and ability to adsorb Rhodamine 6G and crystal violet. Dispersive micro‐solid‐phase extraction parameters were optimized, including sample pH, adsorbent amount, extraction time, and desorption solvent. The optimum polypyrrole‐magnetite dispersive micro‐solid phase‐extraction conditions were sample pH 8, 60 mg polypyrrole‐magnetite adsorbent, 5 min of extraction time, and acetonitrile as the desorption solvent. Under the optimized conditions, the polypyrrole‐magnetite dispersive micro‐solid‐phase extraction with ultraviolet‐visible method showed good linearity in the range of 0.05–7 mg/L (R ² > 0.9980). The method also showed a good limit of detection for the dyes (0.05 mg/L) and good analyte recoveries (97.4–111.3%) with relative standard deviations < 10%. The method was successfully applied to the analysis of dyes in textile wastewater samples where the concentration found was 1.03 mg (RSD ±7.9%) and 1.13 mg/L (RSD ± 4.6%) for Rhodamine 6G and crystal violet, respectively. It can be concluded that this method can be adopted for the rapid extraction and determination of dyes at trace concentration levels.