Application of counter-current chromatography as a new pretreatment method for the determination of polycyclic aromatic hydrocarbons in environmental water

Counter‐current chromatography (CCC) was investigated as a new sample pretreatment method for the determination of trace polycyclic aromatic hydrocarbons (PAHs) in water environmental samples. The experiment was performed with a non‐aqueous binary two‐phase solvent system composed of n‐heptane and acetonitrile. The CCC column was first filled with the upper stationary phase, and then a large volume of water sample was pumped into the column while the CCC column was rotated at 1600 rpm. Finally, the trace amounts of PAHs extracted and enriched in the stationary phase were eluted out by the lower mobile phase and determined by gas chromatography–flame ionization detector (GC‐FID) or gas chromatography–mass spectrometry (GC‐MS). The enrichment and cleanup of PAHs can be fulfilled online by this method with high recoveries (84.1–103.2%) and good reproducibility (RSDs: 4.9–12.2%) for 16 EPA PAHs under the optimized CCC pretreatment conditions. This method has been successfully applied to determine PAHs in lake water where 8 PAHs were detected in the concentration of 40.9–89.9 ng/L. The present method is extremely suitable for the preparation of large volume of environmental water sample for the determination of trace amounts of organic pollutants including PAHs as studied in this paper.     

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.     

Application of liquid-liquid-liquid microextraction and ion-pair liquid chromatography coupled with photodiode array detection for the determination of chlorophenols in water

A method termed as liquid-liquid-liquid microextraction was utilized to extract chlorophenols from water. The extracted chlorophenols, present in anionic form, were then separated, identified, and quantitated by ion-pair high-performance liquid chromatography with photodiode array detection (HPLC/DAD). For trace chlorophenol determination using HPLC/DAD, the chlorophenolate anion provides a better ultraviolet spectrum for quantitative and qualitative analyses than does uncharged chlorophenol. This is due to the auxochromic effect of the phenolate anion. In the study, experimental conditions such as organic phase identity, acceptor phase volume, sample agitation, extraction time, acceptor phase NaOH concentration, donor phase HCl concentration, salt addition, and UV absorption wavelength were optimized. Relative standard deviations (RSD, 2.3-5.4%), coefficients of determination (r2 0.9994-0.9999), and detection limits (0.049-0.081 ng mL(-1)) of the proposed method were investigated under the selected conditions. The method was successfully applied to analyses of reservoir and tap water samples, and the relative recoveries of chlorophenols from the spiked reservoir and tap water samples were 94.1-100.4% and 87.8-101.2%, respectively. The proposed method is capable of identifying and quantitating each analyte to 0.5 ng mL(-1), confirming the HPLC/DAD technique to be quite robust for monitoring trace levels of chlorophenols in water samples.     

气泡富集-高效液相色谱法测定地表水样中微量土霉素

建立了气泡富集-高效液相色谱（HPLC）测定地表水样中微量土霉素的方法。采用新型样品前处理方法--气泡富集法,对水溶液中的微量土霉素进行富集,考察了气泡富集条件对富集效果的影响。研究发现,在优化的气泡富集和色谱条件下,土霉素的富集倍数可达37.06,土霉素含量测定的RSD为4.8%（n=11）,LOD为0.038 mg/L。将该方法用于地表水样中土霉素的测定,平均加标回收率为101.9%。可见,气泡富集法对土霉素的富集效果好,能与色谱结合用于地表水样中土霉素的快速、灵敏、准确检测。同时,在进行样品前处理时无需任何有机溶剂,而且装置简单、成本低廉、易操作。可见气泡富集法是一种非常有研究和推广价值的绿色样品前处理方法,有望用于复杂样品中其他微量甚至痕量物质的分析。     

Determination of tetracycline antibiotics in fatty food samples by selective pressurized liquid extraction coupled with high‐performance liquid chromatography and tandem mass spectrometry

For the determination of trace residues of tetracycline antibiotics in fatty food samples, selective pressurized liquid extraction coupled with high‐performance liquid chromatography and tandem mass spectrometry was applied in this study. Copper(II) isonicotinate was first used as online cleanup adsorbent in the selective pressurized liquid extraction process. The adsorbent to sample ratio, extraction temperature, extraction time, and recycle times, etc. were optimized. The tetracyclines in food samples of pork, chicken meat, and clam meat were detected by liquid chromatography with tandem mass spectrometry. Tetracycline was found at levels of 0.32 and 0.53 μg/g and oxytetracycline was found at 0.14 and 0.21 μg/g in chicken meat and clam meat, respectively, while chlorotetracycline and deoxytetracycline were below the detection limit. The detection limit (S/N = 3) for these four tetracyclines were from 0.2 to 3.3 ng/g, the recoveries were from 75.8 to 110.5%, and relative standard deviations were from 5.5 to 13.6%. Copper(II) isonicotinate showed a higher purification capacity than other cleanup adsorbents for extraction of antibiotics in fatty food and the recovery showed predominance compared with a pressurized liquid extraction method without adsorbent. The study demonstrated that copper(II) isonicotinate would be a promising cleanup adsorbent in pressurized liquid extraction for the analysis of trace organic pollutants in complicated samples.     

Trace analysis of rimantadine in human urine after dispersive liquid liquid microextraction followed by liquid chromatography–post column derivatization

The first dispersive liquid liquid microextraction scheme followed by liquid chromatography‐post column derivatization for the determination of the antiviral drug rimantadine in urine samples is demonstrated. The effect of the type and volume of organic extraction solvent, type and volume of disperser solvent, sample pH, ionic strength, extraction time, and centrifugation speed on the extraction efficiency were studied. Rimantadine and the internal standard (amantadine) were chromatographed using a reversed phase monolithic stationary phase with a mixture of equal volumes of methanol and phosphate buffer (pH = 3) as mobile phase. On‐line post‐column derivatization of the analyte was performed using a “two‐stream” manifold with o‐phthalaldehyde and N‐acetyl‐cysteine at alkaline medium. Under the optimized extraction conditions, the enrichment factor of rimantadine was 58. The linear range was 5–100 µg/L with correlation coefficient r of 0.9984 while the limit of detection achieved was 0.5 µg/L. The within‐day and between‐day precision for the tested concentration levels were less than 14.3% and the mean recoveries obtained from the spiked samples were ranged between 87.5 and 113.9%. The main advantages of the proposed method are the simplicity of operation, rapidity, low cost, and low limit of detection of the analyte.     

Suitability of dispersive liquid–liquid microextraction for the in situ silylation of chlorophenols in water samples before gas chromatography with mass spectrometry

Trace analysis of chlorophenols in water was performed by simultaneous silylation and dispersive liquid–liquid microextraction followed by gas chromatography with mass spectrometry. Dispersive liquid–liquid microextraction was carried out using an organic solvent lighter than water (n‐hexane). The effect of different silylating reagents on the method efficiency was investigated. The influence of derivatization reagent volume, presence of catalyst and derivatization/extraction time on the yield of the derivatization reaction was studied. Different parameters affecting extraction efficiency such as kind and volume of extraction and disperser solvents, pH of the sample and addition of salt were also investigated and optimized. Under the optimum conditions, the calibration graphs were linear in the range of 0.05–100 ng/mL and the limit of detection was 0.01 ng/mL. The enrichment factors were 242, 351, and 363 for 4‐chlorophenol, 2,4‐dichlorophenol, and 2,4,6‐trichlorophenol, respectively. The values of intra‐ and inter‐day relative standard deviations were in the range of 3.0–6.4 and 6.1–9.9%, respectively. The applicability of the method was investigated by analyzing water and wastewater samples.     

Enhancing concentration and mass sensitivities for liquid chromatography trace analysis of clopyralid in drinking water

A theoretical treatment was developed and validated that relates analyte concentration and mass sensitivities to injection volume, retention factor, particle diameter, column length, column inner diameter and detection wavelength in liquid chromatography, and sample volume and extracted volume in solid‐phase extraction (SPE). The principles were applied to improve sensitivity for trace analysis of clopyralid in drinking water. It was demonstrated that a concentration limit of detection of 0.02 ppb (μg/L) for clopyralid could be achieved with the use of simple UV detection and 100 mL of a spiked drinking water sample. This enabled reliable quantitation of clopyralid at the targeted 0.1 ppb level. Using a buffered solution as the elution solvent (potassium acetate buffer, pH 4.5, containing 10% of methanol) in the SPE procedures was found superior to using 100% methanol, as it provided better extraction recovery (70–90%) and precision (5% for a concentration at 0.1 ppb level). In addition, the eluted sample was in a weaker solvent than the mobile phase, permitting the direct injection of the extracted sample, which enabled a faster cycle time of the overall analysis. Excluding the preparation of calibration standards, the analysis of a single sample, including acidification, extraction, elution and LC run, could be completed in 1 h. The method was used successfully for the determination of clopyralid in over 200 clopyralid monoethanolamine‐fortified drinking water samples, which were treated with various water treatment resins.     

A new cleanup method of dioxins in sediment using large volume injection gas chromatography online coupled with liquid chromatography

A new cleanup method was developed and validated for the determination of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) in sediment. The sample extract was first treated with sulfuric acid and then cleaned up by a large volume injection gas chromatography online coupled with liquid chromatography (LVI-GC-LC) system. PCDD/Fs in the extract were separated by a GC column (DB-5), selected cut, cool trapped and transferred to a LC column (alumina). The fraction of PCDD/Fs eluted from the alumina column was collected and concentrated for the instrumental analysis. Under the optimized conditions, LVI-GC-LC method achieved the recoveries of 57–102% for 2,3,7,8-substituted PCDD/Fs, which met the requirements of US Environmental Protection Agency (EPA) Method 1613 and were better than those obtained using the conventional multistep column cleanup method. Meanwhile, compared with the conventional method, the limit of detection (LOD) values of 2,3,7,8-substituted PCDD/Fs cleaned up by LVI-GC-LC method were decreased due to the high-efficiency removal of interferents. These results suggested that the LVI-GC-LC cleanup method was a promising alternative to the multistep cleanup procedure for the determination of dioxins in environmental samples.     

Determination of phthalate esters from environmental water samples by micro‐solid‐phase extraction using TiO2 nanotube arrays before high‐performance liquid chromatography

We describe a highly sensitive micro‐solid‐phase extraction method for the pre‐concentration of six phthalate esters utilizing a TiO₂ nanotube array coupled to high‐performance liquid chromatography with a variable‐wavelength ultraviolet visible detector. The selected phthalate esters included dimethyl phthalate, diethyl phthalate, dibutyl phthalate, butyl benzyl phthalate, bis(2‐ethylhexyl)phthalate and dioctyl phthalate. The factors that would affect the enrichment, such as desorption solvent, sample pH, salting‐out effect, extraction time and desorption time, were optimized. Under the optimum conditions, the linear range of the proposed method was 0.3–200 μg/L. The limits of detection were 0.04–0.2 μg/L (S/N = 3). The proposed method was successfully applied to the determination of six phthalate esters in water samples and satisfied spiked recoveries were achieved. These results indicated that the proposed method was appropriate for the determination of trace phthalate esters in environmental water samples.     

Determination of three estrogens and bisphenol A by functional ionic liquid dispersive liquid‐phase microextraction coupled with ultra‐high performance liquid chromatography and ultraviolet detection

A hydroxyl‐functionalized ionic liquid, 1‐hydroxyethyl‐3‐methylimidazolium bis(trifluoromethanesulfonyl)imide, was employed in an improved dispersive liquid‐phase microextraction method coupled with ultra high performance liquid chromatography for the enrichment and determination of three estrogens and bisphenol A in environmental water samples. The introduced hydroxyl group acted as the H‐bond acceptor that dispersed the ionic liquid effectively in the aqueous phase without dispersive solvent or external force. Fourier transform infrared spectroscopy indicated that the hydroxyl group of the cation of the ionic liquid enhanced the combination of extractant and analytes through the formation of hydrogen bonds. The improvement of the extraction efficiency compared with that with the use of alkyl ionic liquid was proved by a comparison study. The main parameters including volume of extractant, temperature, pH, and extraction time were investigated. The calibration curves were linear in the range of 5.0–1000 μg/L for estrone, estradiol, and bisphenol A, and 10.0–1000 μg/L for estriol. The detection limits were in the range of 1.7–3.4 μg/L. The extraction efficiency was evaluated by enrichment factor that were between 85 and 129. The proposed method was proved to be simple, low cost, and environmentally friendly for the determination of the four endocrine disruptors in environmental water samples.     

Determination of chlorophenols in water using dispersive liquid–liquid microextraction coupled with water‐in‐oil microemulsion electrokinetic chromatography in normal stacking mode

The current routes to couple dispersive liquid–liquid microextraction with capillary electrophoresis are the evaporation of water immiscible extractants and the back‐extraction of analytes. In this study, a new methodology for this combination using water‐in‐oil microemulsion electrokinetic chromatography coupled with normal stacking mode on‐line sample concentration was developed to analyze chlorophenols in water samples. The analytes were extracted with tributyl phosphate and the extractant dilution (3×) was directly injected into an electrophoresis buffer (7.7 cm) containing 5% sodium dodecyl sulfate, 78% 1‐butanol, 2% 1‐heptane, and 15% sodium acetate solution (pH 8.0). This proposed method is very simple and convenient compared to the conventional procedures. The key parameters affecting separation and concentration were systematically optimized. Under the optimized conditions, dispersive liquid–liquid microextraction contributed an enrichment factor of 45–50, and the overall sensitivity improvement was 312–418‐fold. Limits of detection between 1.4 and 3.0 ng/mL and limits of quantification between 4.5 and 10.2 ng/mL were achieved. Acceptable repeatability lower than 3.0% for migration time and 9.0% for peak areas were obtained. The developed method was successfully applied for analysis of the chlorophenols in real water samples.     

Rapid quick,easy, cheap,effective, rugged,and safe extraction with novel phospholipid cleanup: A streamlined ultra high performance liquid chromatography with ultraviolet detection approach for screening polycyclic aromatic hydrocarbons in avian blood cells and plasma

A streamlined method has been developed for the isolation and analysis of polycyclic aromatic hydrocarbons in avian blood cells and plasma utilizing quick, easy, cheap, effective, rugged, and safe extraction in combination with novel phospholipid cleanup technology. A variety of traditional extraction and cleanup techniques have been employed in the preparation and analysis of polycyclic aromatic hydrocarbonsin a variety of matrices; liquid–liquid partitioning, solid‐phase extractions, gel permeation chromatography, and column chromatography are all effective techniques, however they are laborious and time consuming processes that require large amounts of solvent. Using quick, easy, cheap, effective, rugged, and safe extraction coupled with phospholipid cleanup, samples can be quickly screened while maintaining high throughput and sensitivity. With a liquid chromatography approach, analysis times may be kept short at 16 min while maintaining high analyte recovery. Recoveries in quality control samples ranged from 70 to 109%, with average surrogate recoveries of 80.6 ± 1.10%. The result of using a quick, easy, cheap, effective, rugged, and safe extraction approach in conjunction with phospholipid cleanup is a methodology that significantly reduces sample preparation time and solvent use while maintaining high sensitivity and reproducibility.     

Pre‐concentration of trace amount of bisphenol A in water samples by palm leaf ash and determination with high‐performance liquid chromatography

Palm leaf ash was characterized and used as low‐cost adsorbent for solid‐phase extraction and preconcentration of bisphenol A (BPA) in real water samples. Analysis of BPA was carried out using HPLC involving Eurospher 100–5‐C₁₈ (25 cm × 4.5 mm, particle size 5 μm) column and water–acetonitrile (40:60, v/v) as mobile phase. The adsorption was achieved quantitatively at a pH of 6 with elution by 3 mL acetonitrile. The limits of detection and enrichment factor were 0.02 μg L^?1 and 333, respectively. Under optimum conditions the relative standard deviation (RSD) was 2% (n = 10). Comparison of qualification criteria of presented preconcentration procedure with other research indicated that palm leaf ash adsorbent was better than many of the adsorbents in terms of cost and reusability. Also, the limit of detection, precision and enrichment factor were comparable and even better than the previously reported methods. Finally, the efficiency of method was computed by determination of trace amounts of BPA in sea, river, mineral and tap waters with recoveries of 93.3–105.5% and RSDs of 0.61–3.12%.. Briefly, the developed solid‐phase extraction and Preparative layer chromatography (PLC) methods may be used for bisphenol A monitoring in any environmental water sample. Copyright © 2016 John Wiley & Sons, Ltd.     

Determination of organophosphate esters in water samples by mixed‐mode liquid chromatography and tandem mass spectrometry

A simple and sensitive method for the determination of organophosphate esters in water samples by mixed‐mode liquid chromatography with electrospray ionization tandem mass spectrometry coupled with solid‐phase extraction is developed. Using seven alkyl phosphates, three chlorinated alkyl phosphates, and four aryl phosphates as the targets, the developed method was systematically evaluated on the basis of the influence of the solid‐phase extraction cartridge, eluting solvent, sample‐loading volume, mobile phase condition, and the separation of reversed‐phase chromatography and mixed‐mode liquid chromatography. Under the optimal conditions, these organophosphate esters can be extracted by ENVI‐18 cartridge, eluted by 6 mL of 25% dichloromethane in acetonitrile, and then qualified and quantified by mixed‐mode liquid chromatography with tandem mass spectrometry in the multiple reaction‐monitoring mode. The application of mixed‐mode liquid chromatography endows the separation with reasonable retention for both hydrophilic and hydrophobic organophosphate esters regardless of their polarity, which is hardly achieved by reversed‐phase chromatography. Good linearity (from 0.9877 to 0.9969), low quantification limits (1–35 ng/L after extraction of 100 mL of river water), and acceptable recovery rates (58.6–116.2%, with the relative standard deviation <18.0%) were obtained. Finally, the established method was used for analyzing surface water samples, and the good applicability of this method was demonstrated.     

Determination of diflubenzuron and chlorbenzuron in fruits by combining acetonitrile‐based extraction with dispersive liquid–liquid microextraction followed by high‐performance liquid chromatography

In this study, a simple and low‐organic‐solvent‐consuming method combining an acetonitrile‐partitioning extraction procedure followed by “quick, easy, cheap, effective, rugged and safe” cleanup with ionic‐liquid‐based dispersive liquid–liquid microextraction and high‐performance liquid chromatography with diode array detection was developed for the determination of diflubenzuron and chlorbenzuron in grapes and pears. Ionic‐liquid‐based dispersive liquid–liquid microextraction was performed using the ionic liquid 1‐hexyl‐3‐methylimidazolium hexafluorophosphate as the extractive solvent and acetonitrile extract as the dispersive solvent. The main factors influencing the efficiency of the dispersive liquid–liquid microextraction were evaluated, including the extractive solvent type and volume and the dispersive solvent volume. The validation parameters indicated the suitability of the method for routine analyses of benzoylurea insecticides in a large number of samples. The relative recoveries at three spiked levels ranged between 98.6 and 109.3% with relative standard deviations of less than 5.2%. The limit of detection was 0.005 mg/kg for the two insecticides. The proposed method was successfully used for the rapid determination of diflubenzuron and chlorbenzuron residues in real fruit samples.     

Sensitive determination of amide herbicides in environmental water samples by a combination of solid‐phase extraction and dispersive liquid–liquid microextraction prior to GC–MS

In this paper, solid‐phase extraction (SPE) in combination with dispersive liquid–liquid microextraction (DLLME) has been developed as a sample pretreatment method with high enrichment factors for the sensitive determination of amide herbicides in water samples. In SPE–DLLME, amide herbicides were adsorbed quantitatively from a large volume of aqueous samples (100 mL) onto a multiwalled carbon nanotube adsorbent (100 mg). After elution of the target compounds from the adsorbent with acetone, the DLLME technique was performed on the resulting solution. Finally, the analytes in the extraction solvent were determined by gas chromatography–mass spectrometry. Some important extraction parameters, such as flow rate of sample, breakthrough volume, sample pH, type and volume of the elution solvent, as well as salt addition, were studied and optimized in detail. Under optimum conditions, high enrichment factors ranging from 6593 to 7873 were achieved in less than 10 min. There was linearity over the range of 0.01–10 μg/L with relative standard deviations of 2.6–8.7%. The limits of detection ranged from 0.002 to 0.006 μg/L. The proposed method was used for the analysis of water samples, and satisfactory results were achieved.     

Dual‐mode hydrophilic interaction normal phase and reversed phase liquid chromatography of polar compounds on a single column

Adopting a stationary phase convention circumvents problematic definition of the boundary between the stationary and the mobile phase in the liquid chromatography, resulting in thermodynamically consistent and reproducible chromatographic data. Three stationary phase definition conventions provide different retention data, but equal selectivity: (i) the complete solid phase moiety; (ii) the solid porous part carrying the active interaction centers; (iii) the volume of the inner column pores. The selective uptake of water from the bulk aqueous‐organic mobile phase significantly affects the volume and the properties of polar stationary phases. Some polar stationary phases provide dual‐mode retention mechanism in aqueous‐organic mobile phases, reversed‐phase in the water‐rich range, and normal‐phase at high concentrations of the organic solvent in water. The linear solvation energy relationship model characterizes the structural contributions of the non‐selective and selective polar interactions both in the water‐rich and organic solvent‐rich mobile phases. The inner‐pore convention provides a single hold‐up volume value for the retention prediction on the dual‐mode columns over the full mobile phase range. Using the dual‐mode monolithic polymethacrylate zwitterionic micro‐columns alternatively in each mode in the first dimension of two‐dimensional liquid chromatography, in combination with a short reversed‐phase column in the second dimension, provides enhanced sample information.     

Salting‐out assisted liquid–liquid extraction coupled to dispersive liquid–liquid microextraction for the determination of chlorophenols in wine by high‐performance liquid chromatography

A novel procedure of sample preparation combined with high‐performance liquid chromatography with diode array detection is introduced for the analysis of highly chlorinated phenols (trichlorophenols, tetrachlorophenols, and pentachlorophenol) in wine. The main features of the proposed method are (i) low‐toxicity diethyl carbonate as extraction solvent to selectively extract the analytes without matrix effect, (ii) the combination of salting‐out assisted liquid–liquid extraction and dispersive liquid–liquid microextraction to achieve an enrichment factor of 334–361, and (iii) the extract is analyzed by high‐performance liquid chromatography to avoid derivatization. Under the optimum conditions, correlation coefficients (r) were >0.997 for calibration curves in the range 1–80 ng/mL, detection limits and quantification limits ranged from 0.19 to 0.67 and 0.63 to 2.23 ng/mL, respectively, and relative standard deviation was <8%. The method was applied for the determination of chlorophenols in real wines, with recovery rates in the range 82–104%.     

Development and validation of polymerized high internal phase emulsion monoliths coupled with HPLC and fluorescence detection for the determination of trace tetracycline antibiotics in environmental water samples

A polymerized high internal phase emulsion monolith was used as a novel sorbent for solid‐phase extraction coupled with high‐performance liquid chromatography and fluorescence detection for the determination of oxytetracycline, tetracycline, doxycycline, and chlorotetracycline in environmental water samples. The polymerized high internal phase emulsion monolithic column was prepared by the in situ polymerization of the continuous phase of a high internal phase emulsion containing glycidyl methacrylate, styrene, and divinylbenzene in pipette tips, and then functionalized with iminodiacetic acid. The resulting monolith exhibited highly interconnected porosity and large surface areas, making it an excellent candidate as an solid‐phase extraction sorbent for the enrichment of trace tetracycline antibiotics. Several factors affecting the extraction performance of polymerized high internal phase emulsion monoliths, including the pH of sample solution, the eluting solvents, the sample loading flow rate and volume, were investigated, respectively. Under the optimized conditions, the mean recoveries of oxytetracycline, tetracycline, doxycycline, and chlorotetracycline spiked in pond and farm wastewater samples ranged from 78.1 to 119.3% with relative standard deviation less than 15%. The detection limits (S/N = 3) of the proposed method were in the range of 51–137 pg/mL. This study demonstrated that the monolithic polymerized high internal phase emulsion would be promising solid‐phase extraction sorbents in the extraction and proconcentration of trace analytes from complex samples.