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.     

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.     

Low-density solvent-based solvent demulsification dispersive liquid-liquid microextraction for the fast determination of trace levels of sixteen priority polycyclic aromatic hydrocarbons in environmental water samples

For the first time, the low-density solvent-based solvent demulsification dispersive liquid-liquid microextraction was developed for the fast, simple, and efficient determination of 16 priority polycyclic aromatic hydrocarbons (PAHs) in environmental samples followed by gas chromatography-mass spectrometric (GC-MS) analysis. In the extraction procedure, a mixture of extraction solvent (n-hexane) and dispersive solvent (acetone) was injected into the aqueous sample solution to form an emulsion. A demulsification solvent was then injected into the aqueous solution to break up the emulsion, which turned clear and was separated into two layers. The upper layer (n-hexane) was collected and analyzed by GC-MS. No centrifugation was required in this procedure. Significantly, the extraction needed only 2-3 min, faster than conventional DLLME or similar techniques. Another feature of the procedure was the use of a flexible and disposable polyethylene pipette as the extraction device, which permitted a solvent with a density lighter than water to be used as extraction solvent. This novel method expands the applicability of DLLME to a wider range of solvents. Furthermore, the method was simple and easy to use, and some additional steps usually required in conventional DLLME or similar techniques, such as the aforementioned centrifugation, ultrasonication or agitation of the sample solution, or refrigeration of the extraction solvent were not necessary. Important parameters affecting the extraction efficiency were investigated in detail. Under the optimized conditions, the proposed method provided a good linearity in the range of 0.05-50 μg/L, low limits of detection (3.7-39.1 ng/L), and good repeatability of the extractions (RSDs below 11%, n=5). The proposed method was successfully applied to the extraction of PAHs in rainwater samples, and was demonstrated to be fast, efficient, and convenient.     

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.     

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).     

The recent developments in dispersive liquid–liquid microextraction for preconcentration and determination of inorganic analytes

Recently, increasing interest on the use of dispersive liquid–liquid microextraction (DLLME) developed in 2006 by Rezaee has been found in the field of separation science. DLLME is miniaturized format of liquid–liquid extraction in which acceptor-to-donor phase ratio is greatly reduced compared with other methods. In the present review, the combination of DLLME with different analytical techniques such as atomic absorption spectrometry (AAS), inductively coupled plasma-optical emission spectrometry (ICP-OES), gas chromatography (GC), and high-performance liquid chromatography (HPLC) for preconcentration and determination of inorganic analytes in different types of samples will be discussed. Recent developments in DLLME, e.g., displacement-DLLME, the use of an auxiliary solvent for adjustment of density of extraction mixture, and the application of ionic liquid-based DLLME in determination of inorganic species even in the presence of high content of salts are presented in the present review. Finally, comparison of DLLME with the other liquid-phase microextraction approaches and limitations of this technique are provided.     

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.     

分散液相微萃取技术研究的最新进展

分散液相微萃取(DLLME)作为一种新型样品前处理技术,具有操作简便、快速,富集效率高,萃取剂使用量少等优点。本文对近年来该技术在分离科学领域应用的最新进展进行了简要评述。主要讨论了以下3个方面:(1)DLLME与其他净化或萃取技术的结合;(2)萃取剂的拓展;(3)萃取装置的改进。     

Determination of ppb-level phenol index using in-syringe dispersive liquid-liquid microextraction and liquid waveguide capillary cell spectrophotometry

We report on an in-syringe dispersive liquid-liquid microextraction (DLLME) technique and its application to the determination of the total phenol index in natural waters. Xylene was used as extraction solvent in combination with a mixture of acetonitrile and n-propanol as dispersion solvents. The analytical procedure consists of mixing the sample with buffer, reacting it with 4-aminoantipyrine and potassium hexacyanoferrate, DLLME, phase separation, and index quantification and was automated using the multisyringe flow injection analysis technique and takes 200?s only. DLLME was accomplished by aspiration of the mixture of extraction and dispersion solvents followed by the aqueous phases into the syringe at a high flow rate. Phase separation occurs due to aggregation of the floating extractant droplets (with their lower specific density) at the head of the syringe. The extractant containing the chromogenic reaction product is then pushed into an optical waveguide capillary cell and spectrophotometrically detected at 500?nm. Figures of merits include a low limit of detection (0.9?ppb), a preconcentration factor of 20, a linear dynamic range up to 140?ppb, and a general standard deviation of 3.1?%. The method enabled the concentration of phenols in well water samples to be determined with a mean recovery of 101?%.

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.     

Reversed-phase dispersive liquid-liquid microextraction with central composite design optimization for preconcentration and HPLC determination of oleuropein

A reversed-phase dispersive liquid-liquid microextraction (RP-DLLME) method was developed for the preconcentration and direct HPLC determination of oleuropein in olive's processing wastewater (OPW) and olive leaves extracts. In conventional DLLME, the sedimented phase is a micro-drop of a chlorinated organic solvent that is not compatible with RP-HPLC. Therefore, solvent evaporation and reconstitution with an appropriate solvent is often required. In RP-DLLME, this problem was overcome by overturning the solvent polarity in the ordinary DLLME and replacing the organic solvent with water. A central composite chemometrics design was used for multivariate optimization of the effects of five different parameters influencing the extraction efficiency of the method. In the optimized conditions, a mixture of 1.4 mL of an ethyl acetate extract of sample and 40 μL water (pH 5.0) was rapidly injected into 5.3 mL of cyclohexane. After centrifugation of the formed cloudy mixture, a micro-drop of the aqueous phase was sedimented at the conical bottom of the centrifuge tube. This phase, that contained the preconcentrated and partially purified analyte, was directly injected into an RP-HPLC column for analysis. A mean extraction recovery of 102.5 (±4.5) % with enrichment factors exceeding 38, was obtained for five replicated analysis. The detection limit of the method (3σ) for OE was 0.02 μg L⁻¹ for OPW and 2 × 10⁻³ mg kg⁻¹ for olive leaves samples. The results showed that, RP-DLLME is a promising technique which is quick, easily operated and can be directly coupled to HPLC.     

分散液相微萃取-气相色谱联用测定葡萄中百菌清、克菌丹和灭菌丹残留

采用分散液相微萃取与气相色谱-电子捕获检测联用技术建立了测定葡萄样品中百菌清、克菌丹和灭菌丹农药残留的新方法.对影响萃取和富集效率的因素进行了优化.萃取条件选定为在10 mL带塞离心试管中加入 5.0 mL葡萄样品溶液,并加入1.0 mL丙酮(分散剂),振荡摇匀后以5000 r/min离心5 min,然后将上层清液转移至另一离心试管中,加10.0 μL氯苯(萃取剂),分散混匀后再以5000 r/min离心5 min,萃取剂氯苯相沉积到试管底部,吸取1.0 μL萃取相直接进样分析.在优化的实验条件下,3种杀菌剂的富集倍数可达788～876倍;检出限在6.0～8.0 μg/kg(S/N=3∶ 1)范围内.以α-六六六为内标,测定3种杀菌剂的线性范围为10～150 μg/kg,线性相关系数在0.9990～0.9995范围内.本方法已成功应用于葡萄样品中百菌清、克菌丹和灭菌丹残留的测定,平均加标回收率在92.3%～106.1%范围内;相对标准偏差在4.5%～7.2%之间,结果令人满意.     

Sequential dispersive liquid–liquid microextraction for the determination of aryloxyphenoxy‐propionate herbicides in water

A novel dispersive liquid–liquid microextraction (DLLME) method followed by HPLC analysis, termed sequential DLLME, was developed for the preconcentration and determination of aryloxyphenoxy‐propionate herbicides (i.e. haloxyfop‐R‐methyl, cyhalofop‐butyl, fenoxaprop‐P‐ethyl, and fluazifop‐P‐butyl) in aqueous samples. The method is based on the combination of ultrasound‐assisted DLLME with in situ ionic liquid (IL) DLLME into one extraction procedure and achieved better performance than widely used DLLME procedures. Chlorobenzene was used as the extraction solvent during the first extraction. Hydrophilic IL 1‐octyl‐3‐methylimidazolium chloride was used as a dispersive solvent during the first extraction and as an extraction solvent during the second extraction after an in situ chloride exchange by bis[(trifluoromethane)sulfonyl]imide. Several experimental parameters affecting the extraction efficiency were studied and optimized with the design of experiments using MINITAB® 16 software. Under the optimized conditions, the extractions resulted in analyte recoveries of 78–91%. The correlation coefficients of the calibration curves ranged from 0.9994 to 0.9997 at concentrations of 10–300, 15–300, and 20–300 μg L^?1. The relative SDs (n = 5) ranged from 2.9 to 5.4%. The LODs for the four herbicides were between 1.50 and 6.12 μg L^?1.     

Tandem use of solid-phase extraction and dispersive liquid-liquid microextraction for the determination of mononitrotoluenes in aquatic environment

Solid‐phase extraction (SPE) in tandem with dispersive liquid–liquid microextraction (DLLME) has been developed for the determination of mononitrotoluenes (MNTs) in several aquatic samples using gas chromatography‐flame ionization (GC‐FID) detection system. In the hyphenated SPE‐DLLME, initially MNTs were extracted from a large volume of aqueous samples (100 mL) into a 500‐mg octadecyl silane (C₁₈) sorbent. After the elution of analytes from the sorbent with acetonitrile, the obtained solution was put under the DLLME procedure, so that the extra preconcentration factors could be achieved. The parameters influencing the extraction efficiency such as breakthrough volume, type and volume of the elution solvent (disperser solvent) and extracting solvent, as well as the salt addition, were studied and optimized. The calibration curves were linear in the range of 0.5–500 μg/L and the limit of detection for all analytes was found to be 0.2 μg/L. The relative standard deviations (for 0.75 μg/L of MNTs) without internal standard varied from 2.0 to 6.4% (n=5). The relative recoveries of the well, river and sea water samples, spiked at the concentration level of 0.75 μg/L of the analytes, were in the range of 85–118%.     

Optimization of dispersive liquid-liquid microextraction of copper (II) by atomic absorption spectrometry as its oxinate chelate: application to determination of copper in different water samples

In this study a dispersive liquid-liquid microextraction (DLLME) method based on the dispersion of an extraction solvent into aqueous phase in the presence of a dispersive solvent was investigated for the preconcentration of Cu(2+) ions. 8-Hydroxy quinoline was used as a chelating agent prior to extraction. Flame atomic absorption spectrometry using an acetylene-air flame was used for quantitation of the analyte after preconcentration. The effect of various experimental parameters on the extraction was investigated using two optimization methods, one variable at a time and central composite design. The experimental design was performed at five levels of the operating parameters. Nearly the same results for optimization were obtained using both methods: sample size 5 mL; volume of dispersive solvent 1.5 mL; dispersive solvent methanol; extracting solvent chloroform; extracting solvent volume 250 microL; 8-hydroxy quinoline concentration and salt amount do not affect significantly the extraction. Under the optimum conditions the calibration graph was linear over the range 50-2000 muicro L(-1). The relative standard deviation was 5.1% for six repeated determinations at a concentration of 500 microg L(-1). The limit of detection (S/N=3) was 3 microg L(-1).     

Recent trends in replacement of disperser solvent in dispersive liquid-liquid microextraction methods

Since its innovation in 2006, the dispersive liquid-liquid microextraction (DLLME) method has attracted the attention of analytical chemists in the field of sample preparation. This method has been successfully applied to determine trace amounts of pollutants in various matrices, but the restriction in the choice of suitable disperser and extraction solvents, and high disperser solvent consumption leading to decreased partition coefficients of the analytes between aqueous phase and extractant are its problems. To solve these drawbacks and develop environmentally friendly techniques, various alternatives for the conventional DLLME have been presented. The current review will begin with an introduction to the sample preparation, implementation of DLLME, and its advantages. Then, we focus on its drawbacks, which result mainly from the use of disperser solvent. Afterward, some of the most interesting approaches that have been employed and published until now are reviewed. Finally, an outlook on the future of these techniques will be given.     

Molecular complex-based dispersive liquid-liquid microextraction: analysis of polar compounds in aqueous solution

A novel molecular complex-based dispersive liquid-liquid microextraction (DLLME) method was established via hydrogen bond interaction between the extractant and the analytes. In this approach, tri-n-butylphosphate (TBP), a Lewis base, was directly used, instead of the traditional water-immiscible organic solvents, as the extractant for DLLME. The phenols (p-benzenediol, m-benzenediol, o-benzenediol and phenol), which are typical Lewis acids, were successfully extracted from environmental aqueous samples. In addition, phase separation was achieved in a disposable polyethylene pipet with the open and narrow tip upside, for a collection of the above extractant layer, i.e. TBP. To achieve satisfactory extraction performance, several extraction parameters, such as type of extractant solvents, extractant volume, pH of sample solution, ionic strength of sample solution and extraction time, were optimized. Additionally, the proposed method was applied to environmental water samples. Under the optimized conditions, the limits of detection and limits of quantification for the phenols were 7-29 and 25-98 μg/L, respectively. The calibration curves showed good linearity (r(2)≥0.9961) over the investigated concentration range. The repeatability of the method was investigated by evaluating the intra- and inter-day precisions. The relative standard deviations (RSDs) obtained were lower than 11.2% and 13.9% at different concentration levels. The recoveries ranged from 83.2% to 117.8%, with RSDs less than 13.1%. The developed approach provides a new way to facilitate DLLME of organic polar compounds from aqueous solutions. Moreover, it enables a convenient collection of solvent less dense making use of a cheap and disposable polyethylene pipet.     

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.