基于轻质萃取剂的溶剂去乳化分散液-液微萃取-气相色谱法测定水样中多环芳烃

以密度小于水的轻质溶剂为萃取剂,建立了无需离心步骤的溶剂去乳化分散液-液微萃取-气相色谱(SD-DLLME-GC)测定水样中多环芳烃的新方法。传统分散液-液微萃取技术一般采用密度大于水的有机溶剂为萃取剂,并需要通过离心步骤促进分相。而本方法以密度比水小的轻质溶剂甲苯为萃取剂,将其与丙酮(分散剂)混合并快速注入水样,获得雾化体系;然后注入乙腈作为去乳化剂,破坏该雾化体系,无需离心,溶液立即澄清、分相;取上层有机相(甲苯)进行GC分析。考察了萃取剂、分散剂、去乳化剂的种类及其体积等因素对萃取率的影响。以40 μL甲苯为萃取剂,500 μL丙酮为分散剂,800 μL乙腈为去乳化剂,方法在20～500 μg/L范围内呈现出良好的线性(r2=0.9942～0.9999),多环芳烃的检出限(S/N=3)为0.52～5.11 μg/L。用所建立的方法平行测定5份质量浓度为40 μg/L的多环芳烃标准水样,其含量的相对标准偏差为2.2%～13.6%。本法已成功用于实际水样中多环芳烃的分析,并测得其加标回收率为80.2%～115.1%。     

Determination of volatile nitrosamines in meat products by microwave-assisted extraction and dispersive liquid-liquid microextraction coupled to gas chromatography-mass spectrometry

Microwave-assisted extraction (MAE) and dispersive liquid-liquid microextraction (DLLME) coupled with gas chromatography-mass spectrometry (GC-MS) were evaluated for use in the extraction and preconcentration of volatile nitrosamines in meat products. Parameters affecting MAE, such as the extraction solvent used, and DLLME, including the nature and volume of the extracting and disperser solvents, extraction time, salt addition and centrifugation time, were optimized. In the MAE method, 0.25g of sample mass was extracted in 10mL NaOH (0.05M) in a closed-vessel system. For DLLME, 1.5mL of methanol (disperser solvent) containing 20μL of carbon tetrachloride (extraction solvent) was rapidly injected by syringe into 5mL of the sample extract solution (previously adjusted to pH 6), thereby forming a cloudy solution. Phase separation was performed by centrifugation, and a volume of 3μL of the sedimented phase was analyzed by GC-MS. The enrichment factors provided by DLLME varied from 220 to 342 for N-nitrosodiethylamine and N-nitrosopiperidine, respectively. The matrix effect was evaluated for different samples, and it was concluded that sample quantification can be carried out by aqueous calibration. Under the optimized conditions, detection limits ranged from 0.003 to 0.014ngmL(-1) for NPIP and NMEA, respectively (0.12-0.56ngg(-1) in the meat products).     

Simultaneous derivatization and extraction of anilines in waste water with dispersive liquid-liquid microextraction followed by gas chromatography-mass spectrometric detection

The one-step derivatization and extraction technique for the determination of anilines in river water by dispersive liquid-liquid microextraction (DLLME) is presented. In this method the anilines are extracted by DLLME and derivatized with pentafluorobenzaldehyde (PFBAY) in aqueous solution simultaneously. In this derivatization/extraction method, 0.5 ml acetone (disperser solvent) containing 10 microl chlorobenzene (extraction solvent) and 30 g/l pentafluorobenzaldehyde (PFBAY) dissolved in methanol was rapidly injected by syringe into 5 ml aqueous sample (pH 4.6). Within 20 min the analytes extracted and derivatized were almost finished. After centrifugation, 2 microl sedimented phase containing enriched analytes was determined by GC-MS. The effects of extraction and disperser solvent type and their volume, pH value of sample solution, derivatization and extraction time, derivatization and extraction temperature were investigated. Linearity in this developed method was ranging from 0.25 to 70 microg/l, and the correlation coefficients (R2) were between 0.9955 and 0.9989, and reasonable reproducibility ranging from 5.8 to 11.8% (n=5). Method detection limits (MDLs) ranged from 0.04 to 0.09 microg/l (n=5).     

Evaluation of dispersive liquid-liquid microextraction for the simultaneous determination of chlorophenols and haloanisoles in wines and cork stoppers using gas chromatography-mass spectrometry

Dispersive liquid-liquid microextraction (DLLME) coupled with gas chromatography-mass spectrometry (GC-MS) was evaluated for the simultaneous determination of five chlorophenols and seven haloanisoles in wines and cork stoppers. Parameters, such as the nature and volume of the extracting and disperser solvents, extraction time, salt addition, centrifugation time and sample volume or mass, affecting the DLLME were carefully optimized to extract and preconcentrate chlorophenols, in the form of their acetylated derivatives, and haloanisoles. In this extraction method, 1mL of acetone (disperser solvent) containing 30μL of carbon tetrachloride (extraction solvent) was rapidly injected by a syringe into 5mL of sample solution containing 200μL of acetic anhydride (derivatizing reagent) and 0.5mL of phosphate buffer solution, thereby forming a cloudy solution. After extraction, phase separation was performed by centrifugation, and a volume of 4μL of the sedimented phase was analyzed by GC-MS. The wine samples were directly used for the DLLME extraction (red wines required a 1:1 dilution with water). For cork samples, the target analytes were first extracted with pentane, the solvent was evaporated and the residue reconstituted with acetone before DLLME. The use of an internal standard (2,4-dibromoanisole) notably improved the repeatability of the procedure. Under the optimized conditions, detection limits ranged from 0.004 to 0.108ngmL(-1) in wine samples (24-220pgg(-1) in corks), depending on the compound and the sample analyzed. The enrichment factors for haloanisoles were in the 380-700-fold range.     

Development of a dispersive liquid–liquid microextraction (DLLME) method coupled with GC/MS as a simple and valid method for simultaneous determination of phthalate metabolites in plasma

Phthalates are ubiquitous environmental contaminants, and frequent biological monitoring of their metabolites (as toxic species of phthalates in human body) is highly recommended. A novel dispersive liquid–liquid microextraction (DLLME) coupled with Gas Chromatography–Mass Spectrometry (GC-MS) has been developed for the determination of seven phthalate metabolites in human plasma for the first time. Plasma proteins were efficiently precipitated by adding of 0.2mg dry trichloroacetic acid to 10 mL plasma samples, incubation and centrifuging. For DLLME, a mixture of extraction solvent (chlorobenzene, 10 µL) and dispersive solvent (acetonitrile, 750 µL) were rapidly injected into 5.0 mL aqueous sample for the formation of cloudy solution, the analytes in the sample were extracted into the fine droplets of chlorobenzene. After extraction, phase separation was performed by centrifugation and the enriched analytes in the sedimented phase were subjected to GC-MS analysis. All important parameters affecting DLLME performance were investigated and optimised. Under the optimum extraction condition, the method yields a linear calibration curve for all target analytes in the concentration range from 5 to 5000 ng mL^?1. The limits of detection and relative standard deviations for all phthalate metabolites were between 1.21–2.09 ng mL^?1 and 4.8–6.8%, respectively. This is a very simple, rapid and reproducible method, which requires low volume of sample and toxic solvents.     

High‐density extraction solvent‐based solvent de‐emulsification dispersive liquid–liquid microextraction combined with MEKC for detection of chlorophenols in water samples

For the first time, the high‐density solvent‐based solvent de‐emulsification dispersive liquid–liquid microextraction (HSD‐DLLME) was developed for the fast, simple, and efficient determination of chlorophenols in water samples followed by field‐enhanced sample injection with reverse migrating micelles in CE. The extraction of chlorophenols in the aqueous sample solution was performed in the presence of extraction solvent (chloroform) and dispersive solvent (acetone). A de‐emulsification solvent (ACN) was then injected into the aqueous solution to break up the emulsion, the obtained emulsion cleared into two phases quickly. The lower layer (chloroform) was collected and analyzed by field‐enhanced sample injection with reverse migrating micelles in CE. Several important parameters influencing the extraction efficiency of HSD‐DLLME such as the type and volume of extraction solvent, disperser solvent and de‐emulsification solvent, sample pH, extraction time as well as salting‐out effects were optimized. Under the optimized conditions, the proposed method provided a good linearity in the range of 0.02–4 μg/mL, low LODs (4 ng/mL), and good repeatability of the extractions (RSDs below 9.3%, n = 5). And enrichment factors for three phenols were 684, 797, and 233, respectively. This method was then utilized to analyze two real environmental samples from wastewater and tap water and obtained satisfactory results. The obtained results indicated that the developed method is an excellent alternative for the routine analysis in the environmental field.     

Determination of organic compounds in water using dispersive liquid-liquid microextraction

A new microextraction technique termed dispersive liquid-liquid microextraction (DLLME) was developed. DLLME is a very simple and rapid method for extraction and preconcentration of organic compounds from water samples. In this method, the appropriate mixture of extraction solvent (8.0 microL C2Cl4) and disperser solvent (1.00 mL acetone) are injected into the aqueous sample (5.00 mL) by syringe, rapidly. Therefore, cloudy solution is formed. In fact, it is consisted of fine particles of extraction solvent which is dispersed entirely into aqueous phase. After centrifuging, the fine particles of extraction solvent are sedimented in the bottom of the conical test tube (5.0 +/- 0.2 microL). The performance of DLLME is illustrated with the determination of polycyclic aromatic hydrocarbons (PAHs) in water samples by using gas chromatography-flame ionization detection (GC-FID). Some important parameters, such as kind of extraction and disperser solvent and volume of them, and extraction time were investigated. Under the optimum conditions the enrichment factor ranged from 603 to 1113 and the recovery ranged from 60.3 to 111.3%. The linear range was 0.02-200 microg/L (four orders of magnitude) and limit of detection was 0.007-0.030 microg/L for most of analytes. The relative standard deviations (RSDs) for 2 microg/L of PAHs in water by using internal standard were in the range 1.4-10.2% (n = 5). The recoveries of PAHs from surface water at spiking level of 5.0 microg/L were 82.0-111.0%. The ability of DLLME technique in the extraction of other organic compounds such as organochlorine pesticides, organophosphorus pesticides and substituted benzene compounds (benzene, toluene, ethyl benzene, and xylenes) from water samples were studied. The advantages of DLLME method are simplicity of operation, rapidity, low cost, high recovery, and enrichment factor.     

A dispersive liquid-liquid microextraction using a switchable polarity dispersive solvent. Automated HPLC-FLD determination of ofloxacin in chicken meat

In this article, dispersive liquid-liquid microextraction (DLLME), based on the use of so-called switchable polarity dispersive solvent (SPDS) for microextraction, is presented for the first time. The new extraction technique makes use of a mixture of extraction solvent (dichloromethane) and the SPDS (acrylic acid). This mixture is injected into the aqueous sample solution, which was previously fortified with the alkaline agent (NaOH). The SPDS is dissolved in aqueous phase and a cloudy solution consisting of fine droplets of extraction solvent fully dispersed in the aqueous phase is observed. Simultaneously, as a consequence of the fast neutralization reaction, the SPDS investigated is converted into water-soluble salt and phase separation is achieved because the SPDS switches its polarity. Conversion of the SPDS excludes the negative influence of the conventional dispersive solvents used in DLLME on the solubility of target analytes in aqueous phase and, as a result, increases the DLLME efficiency.     

A procedure for determination of cobalt in water samples after dispersive liquid–liquid microextraction

In this work, a procedure for preconcentration of cobalt using dispersive liquid–liquid microextraction (DLLME) with the reagent Br-TAO as complexing reagent was developed. The procedure is based on a ternary system of solvents, where appropriate amounts of the extraction solvent, disperser solvent and the chelating agent Br-TAO are directly injected into an aqueous solution containing Co(II). A cloudy mixture is formed and the ions are extracted in the fine droplets of the extraction solvent. After extraction, the phase separation is performed with a rapid centrifugation, and cobalt is determined in the enriched phase by FAAS. Under the optimized conditions, the detection limit obtained was 0.9 µg L^{− 1}. The enrichment factor and the consumptive index were 16 and 0.31 mL, respectively. The accuracy of the method was tested by the determination of cobalt in certified reference material of spinach leaves, NIST 1570a. The proposed procedure was successfully applied to the determination of cobalt in water samples.     

Use of dispersive liquid-liquid microextraction for simultaneous preconcentration of samarium,europium, gadolinium and dysprosium

A new preconcetration method of dispersive liquid-liquid microextraction (DLLME) was developed for simultaneous preconcentration of samarium, europium, gadolinium and dysprosium. DLLME technique was successfully used as a sample preparation method. In this preconcentration method, an appropriate mixture of extraction solvent, disperser solvent was injected rapidly into an aqueous solution containing Sm, Eu, Gd and Dy after complex formation using chelating reagent of the 1-(2-pyridylazo)-2-naphthol (PAN). After phase separation, 0.5 mL of the settled phase containing enriched analytes was determined by inductively coupled plasma optical emission spectrometry (ICP-OES). The main factors affected the preconcentration of Sm, Eu, Gd and Dy were extraction and dispersive solvent type and their volume, extraction time, volume of chelating agent (PAN), centrifuge speed and drying temperature of the samples. Under the best operating condition simultaneous preconcentration factors of 80, 100, 103 and 78 were obtained for Sm, Eu, Gd and Dy, respectively.     

溶剂去乳化-悬浮固化分散液液微萃取-气相色谱-质谱联用测定水中的有机氯农药

建立了溶剂去乳化-悬浮固化分散液液微萃取技术结合气相色谱-质谱联用技术同时测定水样中8种有机氯农药的方法。以正十六烷作为萃取剂,将其与分散剂丙酮混合后,快速注入水样,获得乳化体系并完成萃取;然后加入丙酮作为去乳化剂破坏乳化体系,不需要经过离心即能使两相分层;经冰浴冷冻使其固化后,取出上层凝固的有机相(正十六烷)在室温下融化,取上清液进行GC-MS分析。考察了萃取剂、分散剂、去乳化剂的种类和体积,水样盐浓度和pH值对萃取效率的影响。结果表明,8种有机氯农药在0.025~2.00 μg/L范围内有良好的线性关系(r=0.9995~0.9999), 8种有机氯农药的检出限为0.012~0.024 μg/L,精密度为3.15%~4.53%,富集倍数为96~101。将该方法应用于农田池塘水的测定,加标回收率为96.77%~102.93%,精密度为2.68%~4.86%。方法快速灵敏,有机溶剂消耗少,对环境友好,操作简便,适用于水中有机氯农药的批量分析,并为实现其样品前处理的自动化提供了技术和方法学的支持。     

Determination of carbamazepine in formulation samples using dispersive liquid–liquid microextraction method followed by ion mobility spectrometry

A simple, sensitive, fast and efficient method based on dispersive liquid–liquid microextraction (DLLME) followed by ion mobility spectrometry (IMS) has been proposed for preconcentration and trace detection of carbamazepine (CBZ) in formulation samples. In this method, 1 mL of methanol (disperser solvent) containing 80 μL of chloroform (extraction solvent) was rapidly injected by a syringe into a sample. After 5 min centrifugation, the preconcentrated carbamazepine in the organic phase was determined by IMS. Development of DLLME procedure includes optimization of parameters influencing the extraction efficiencies such as kind and volume of extraction solvent, disperser solvent and salt addition, centrifugation time and pH of the sample solution. The proposed method presented good linearity in the range of 0.05–10 μg mL^?1 and the detection limit was 0.025 μg mL^?1. The repeatability of the method expressed as relative standard deviation was 6 % (n = 5). This method has been applied to the analysis of carbamazepine formulation samples with satisfactory relative recoveries ≤75 %.     

Fast analysis of multiple pesticide residues in apple juice using dispersive liquid–liquid microextraction and multidimensional gas chromatography–mass spectrometry

A method for the rapid trace analysis of 24 residual pesticides in apple juice by multidimensional gas chromatography–mass spectrometry (MD-GC/MS) using dispersive liquid–liquid microextraction (DLLME) was developed and optimized. Several parameters of the extraction procedure such as type and volume of extraction solvent, type and volume of dispersive solvent and salt addition were evaluated to achieve the highest yield and to attain the lowest detection limits. The DLLME procedure optimized consists in the formation of a cloudy solution promoted by the fast addition to the sample (5 ml) of a mixture of carbon tetrachloride (extraction solvent, 100 μl) and acetone (dispersive solvent, 400 μl). The tiny droplets formed and dispersed among the aqueous sample solution are further joined and sedimented (85 μl) in the bottom of the conical test tube by centrifugation. Once extracted, all the 24 pesticides were directly injected and separated by a dual GC column system, comprising a short wide-bore DB-5 capillary column with low film thickness connected by a Deans switch system to a second chromatographic narrower column, with identical stationary phase. The instrumental setting used, in combination with carefully optimized operational fast GC and MS parameters, markedly decreased the retention times of the targeted analytes. The total chromatographic run was 8 min. Mean recoveries for apple juice spiked at three concentrations ranged from 60% to 105% and the intra-repeatability ranged from 1% to 21%. The limits of detection of the 24 pesticides ranged from 0.06 to 2.20 μg/L. In 2 of a total of 28 analysed samples were found residues of captan, although at levels below the maximum limit legal established.     

Application of dispersive liquid-liquid microextraction combined with high-performance liquid chromatography for the determination of methomyl in natural waters

A new method was developed for determination of methomyl in water samples by combining a dispersive liquid-liquid microextraction (DLLME) technique with HPLC-variable wavelength detection (VWD). In this extraction method, 0.50 mL of methanol (as dispersive solvent) containing 20.0 microL of tetrachloroethane (as extraction solvent) was rapidly injected by syringe into a 5.00-mL water sample containing the analyte, thereby forming a cloudy solution. After phase separation by centrifugation for 2 min at 4000 rpm, the enriched analyte in the settled phase (8 +/- 0.2 microL) was at the bottom of the conical test tube. A 5.0-microL volume of the settled phase was analyzed by HPLC-VWD. Parameters such as the nature and volume of the extraction solvent and the dispersive solvent, extraction time, and the salt concentration were optimized. Under the optimum conditions, the enrichment factor could reach 70.7 for a 5.00-mL water sample and the linear range, detection limit (S/N = 3), and precision (RSD, n = 6) were 3-5000 ng/mL, 1.0 ng/mL, and 2.6%, respectively. River and lake water samples were successfully analyzed by the proposed method. Comparison of this method with solid-phase extraction, solid-phase microextraction, and single-drop microextraction, indicates that DLLME combined with HPLC-VWD is a simple, fast, and low-cost method for the determination of methomyl, and thus has tremendous potential in trace analysis of methomyl in natural waters.     

Air-assisted liquid–liquid microextraction by solidifying the floating organic droplets for the rapid determination of seven fungicide residues in juice samples

A novel air assisted liquid–liquid microextraction using the solidification of a floating organic droplet method (AALLME-SFO) was developed for the rapid and simple determination of seven fungicide residues in juice samples, using the gas chromatography with electron capture detector (GC-ECD). This method combines the advantages of AALLME and dispersive liquid–liquid microextraction based on the solidification of floating organic droplets (DLLME-SFO) for the first time. In this method, a low-density solvent with a melting point near room temperature was used as the extraction solvent, and the emulsion was rapidly formed by pulling in and pushing out the mixture of aqueous sample solution and extraction solvent for ten times repeatedly using a 10-mL glass syringe. After centrifugation, the extractant droplet could be easily collected from the top of the aqueous samples by solidifying it at a temperature lower than the melting point. Under the optimized conditions, good linearities with the correlation coefficients (γ) higher than 0.9959 were obtained and the limits of detection (LOD) varied between 0.02 and 0.25 μg L⁻¹. The proposed method was applied to determine the target fungicides in juice samples and acceptable recoveries ranged from 72.6% to 114.0% with the relative standard deviations (RSDs) of 2.3–13.0% were achieved. Compared with the conventional DLLME method, the newly proposed method will neither require a highly toxic chlorinated solvent for extraction nor an organic dispersive solvent in the application process; hence, it is more environmentally friendly.     

Application of dispersive liquid–liquid microextraction and reversed phase-high performance liquid chromatography for the determination of two fungicides in environmental water samples

Dispersive liquid–liquid microextraction (DLLME) has been developed for the extraction and preconcentration of diethofencarb (DF) and pyrimethanil (PM) in environmental water. In the method, a suitable mixture of extraction solvent (50 µL carbon tetrachloride) and dispersive solvent (0.75 mL acetonitrile) are injected into the aqueous samples (5.00 mL) and the cloudy solution is observed. After centrifugation, the enriched analytes in the sediment phase were determined by HPLC-VWD. Different influencing factors, such as the kind and volume of extraction and dispersive solvent, extraction time and salt effect were investigated. Under the optimum conditions, the enrichment factors for DF and PM were both 108 and the limit of detection were 0.021 ng mL^?1 and 0.015 ng mL^?1, respectively. The linear ranges were 0.08–400 ng mL^?1 for DF and 0.04–200 ng mL^?1 for PM. The relative standard deviation (RSDs) were both almost at 6.0% (n = 6). The relative recoveries from samples of environmental water were from the range of 87.0 to 107.2%. Compared with other methods, DLLME is a very simple, rapid, sensitive (low limit of detection) and economical (only 5 mL volume of sample) method.     

Analysis of volatile aldehyde biomarkers in human blood by derivatization and dispersive liquid–liquid microextraction based on solidification of floating organic droplet method by high performance liquid chromatography

A new dispersive liquid–liquid microextraction based on solidification of floating organic droplet method (DLLME-SFO) was developed for the determination of volatile aldehyde biomarkers (hexanal and heptanal) in human blood samples. In the derivatization and extraction procedure, 2,4-dinitrophenylhydrazine (DNPH) as derivatization reagent and formic acid as catalyzer were injected into the sample solution for derivatization with aldehydes, then the formed hydrazones was rapidly extracted by dispersive liquid–liquid microextraction with 1-dodecanol as extraction solvent. After centrifugation, the floated droplet was solidified in an ice bath and was easily removed for analysis. The effects of various experimental parameters on derivatization and extraction conditions were studied, such as the kind and volume of extraction solvent and dispersive solvent, the amount of derivatization reagent, derivatization temperature and time, extraction time and salt effect. The limit of detections (LODs) for hexanal and heptanal were 7.90 and 2.34 nmol L⁻¹, respectively. Good reproducibility and recovery of the method were also obtained. The proposed method is an alternative approach to the quantification of volatile aldehyde biomarkers in complex biological samples, being more rapid and simpler and providing higher sensitivity compared with the traditional dispersive liquid–liquid microextraction (DLLME) methods.     

多次溶剂萃取-气相色谱/串联质谱法测定热熔胶中的多环芳烃

建立了热熔胶中16种多环芳烃( PAHs)的多次溶剂萃取-气相色谱/串联质谱测定方法。详细研究了样品的萃取条件、净化条件和气相色谱/串联质谱测定条件,并与气相色谱-质谱法进行了对比。样品以10 mL正己烷为萃取溶剂,于60℃超声萃取20 min,萃取液依次经冷冻后离心、二甲基亚砜萃取2次、正己烷反萃取2次进行净化,得到的净化液以气相色谱/串联质谱法多反应监测( MRM)模式进行检测。本方法的线性相关系数( R2)均大于0.9969,检出限为1.0~10μg/kg,精密度小于6.3%,16种PAHs的加标回收率为80.4%~117.6%。考察了串联质谱检测的基质效应,发现基质效应不明显。本方法检出限优于气相色谱-质谱法(23~94μg/kg),并能增加定性和定量分析的准确性。本方法灵敏、准确可靠,满足热熔胶中PAHs测试要求。     

分散液液微萃取-气相色谱/质谱法测定水中多环芳烃

用分散液液微萃取-气相色谱/质谱法测定水样中的16种多环芳烃(PAHs)。通过实验确定最佳萃取条件为:20μL四氯化碳作萃取剂,1.0 mL乙腈作分散剂,超声萃取1 min。在优化条件下,多环芳烃的富集倍数达到216～511,方法在0.05～50μg/L范围内呈良好的线性关系,相关系数(R2)在0.9873～0.9983之间,检出限为0.0020～0.14μg/L。相对标准偏差(RSD)在3.82%～12.45%(n=6)之间。该方法成功用于实际水样中痕量多环芳烃的测定。     

Determination of organochlorine pesticides in water samples by dispersive liquid-liquid microextraction coupled to gas chromatography-mass spectrometry

A rapid and simple dispersive liquid-liquid microextraction (DLLME) has been developed to preconcentrate eighteen organochlorine pesticides (OCPs) from water samples prior to analysis by gas chromatography-mass spectrometry (GC-MS). The studied variables were extraction solvent type and volume, disperser solvent type and volume, aqueous sample volume and temperature. The optimum experimental conditions of the proposed DLLME method were: a mixture of 10 μL tetrachloroethylene (extraction solvent) and 1 mL acetone (disperser solvent) exposed for 30 s to 10 mL of the aqueous sample at room temperature (20 °C). Centrifugation of cloudy solution was carried out at 2300 rpm for 3 min to allow phases separation. Finally, 2 μL of extractant was recovered and injected into the GC-MS instrument. Under the optimum conditions, the enrichment factors ranged between 46 and 316. The calculated calibration curves gave a high-level linearity for all target analytes with correlation coefficients ranging between 0.9967 and 0.9999. The repeatability of the proposed method, expressed as relative standard deviation, varied between 5% and 15% (n = 8), and the detection limits were in the range of 1-25 ng L⁻¹. The LOD values obtained are able to detect these OCPs in aqueous matrices as required by EPA methods 525.2 and 625. Analysis of spiked real water samples revealed that the matrix had no effect on extraction for river, surface and tap waters; however, urban wastewater sample shown a little effect for five out of eighteen analytes.