Determination of phenols in environmental water samples by ionic liquid-based headspace liquid-phase microextraction coupled with high-performance liquid chromatography

Headspace liquid-phase microextraction (HS-LPME) has been applied to efficient enrichment of phenols such as 2-nitrophenol, 4-chlorophenol, 2,4-dichlorophenol, and 2-naphthol from water samples based on 1-butyl-3-methylimidazolium hexafluorophosphate ([C4MIM][PF6]) as an extractant. Some parameters that may influence HS-LPME were investigated. The linear range was in the range of 0.5-100 microg/L, and the enrichment factors and repeatability (RSD, n = 6) of the proposed method were in the range of 17.2-160.7 and 5.4-8.9%, respectively. The detection limit for each analyte ranged from 0.3 to 0.5 microg/L. Complex matrices of environmental water samples had a small effect on the enrichment, and this problem could be resolved by the addition of sodium ethylene diamine tetraacetate (EDTA) into the samples. The spiked recoveries were in the range of 89.4-114.2%. All these facts demonstrated that the proposed method, with merits of low cost, simplicity, and easy operation, would be a competitive alternative procedure for the determination of such compounds at trace level.     

SPME-GC联用测定环境水样中的酚类化合物

建立了固相微萃取与气相色谱联用技术测定环境水样中酚类化合物的方法. 探讨了pH、离子强度、萃取头类型、萃取时间以及解析时间等条件对酚类化合物萃取量的影响, 优化了GC仪器条件. 在优化的条件下, 酚类化合物的响应值与浓度有良好的线性关系, 线性范围为0.20～200 μg/L, 检出限在0.019～0.10 μg/L之间, 相对标准偏差(RSD, n=5)为4.4%～11%, 水样平均加标回收率为92.2%～101.9%, 所建立的方法可测定环境水样中的酚类化合物.     

中空纤维三相液相微萃取-高效液相色谱法测定水中的4种酚类化合物

建立了中空纤维液-液-液三相微萃取-高效液相色谱法测定水中4种酚类化合物的方法.实验系统地优化了影响萃取效率的因素(包括有机溶剂种类、接收相浓度、分散相pH值、加盐量、转速及萃取时间).得到的最佳萃取条件为:萃取剂为正辛醇,接收相NaOH溶液的浓度为0.09 mol/L,分散相的pH为4,萃取时间为40 min,搅拌速...     

液相微萃取-高效液相色谱法分析葡萄汁中多酚类化合物

建立了一种基于液相微萃取与高效液相色谱联用技术测定葡萄汁中鞣花酸、白藜芦醇和槲皮素的分析方法. 比较了单液滴液相微萃取和中空纤维液相微萃取两种萃取模式, 选择了单液滴液相微萃取作为3种多酚类化合物的液相微萃取模式. 考察了搅拌速度、萃取时间、料液相pH和料液相离子强度的影响. 鞣花酸、白藜芦醇和槲皮素的富集倍数分别为48.4、 79.4和155.8, 方法的线性范围为0.0050～5.0 μg/mL, 鞣花酸、白藜芦醇和槲皮素的检出限分别为0.015, 0.0020, 0.0080 μg/mL, 相对标准偏差分别为2.0%, 1.8%和1.7%. 用于实际样品葡萄汁的分析, 加标回收率在81.9%～102.3%之间.     

微波辅助-顶空液相微萃取在线联用-高效液相色谱法测定环境水样中的敌敌畏

基于微波辅助-顶空液相微萃取联用(MAE-HS-LPME)这一样品前处理方法,采用高效液相色谱法(HPLC)对水样中的敌敌畏残留量进行了测定。对影响萃取的因素如萃取剂、微波辐射功率、萃取时间、离子强度和样品基质的pH值等进行了考察。萃取条件为: 选用二甲苯作萃取剂,萃取时间为15 min,微波辐射功率300 W,NaCl含量为5%,pH为2.5。在最佳条件下,敌敌畏的检出限(信噪比为3时)为0.96 μg/L,定量限(信噪比为10时)为3.20 μg/L,萃取富集倍数为54,实际水样的加标回收率为87.4%～103%。与传统的前处理方法相比,本方法具有简便、快速、高效、节省溶剂、选择性好、应用范围广的特点。     

Determination of triazine herbicides in environmental samples by dispersive liquid-liquid microextraction coupled with high performance liquid chromatography

A simple, rapid, efficient, and environmentally friendly method for the determination of five triazine herbicides in water and soil samples was developed by using dispersive liquid-liquid microextraction (DLLME), coupled with high performance liquid chromatography-diode array detection (HPLC-DAD). The water samples were directly used for DLLME extraction. For soil samples, the target analytes were first extracted by water-methanol (99:1, v/v). In the DLLME extraction method, chloroform was used as an extraction solvent, and acetonitrile as a dispersive solvent. Under the optimum conditions, the enrichment factors of DLLME were in the range between 183-221. The linearity of the method was obtained in the range of 0.5-200 ng/mL for the water sample analysis, and 1-200 ng/g for the soil samples, respectively. The correlation coefficients ranged from 0.9968 to 0.9999. The limits of detection were 0.05-0.1 ng/mL for the water samples, and 0.1-0.2 ng/g for the soil samples. The proposed method has been successfully applied to the analysis of target triazine herbicides (simazin, atrazine, prometon, ametryn, and prometryn) in water and soil samples with satisfactory results.     

分散液-液微萃取-高效液相色谱法测定环境水样中的多环芳烃

建立了简便、快速、有效的分散液-液微萃取-高效液相色谱-荧光检测(DLLME-HPLC-FLD)测定环境水样中15种多环芳烃(PAHs)的方法。重点探讨了萃取剂的种类和用量、分散剂的种类和用量以及萃取时间等对PAHs萃取效率的影响。在优化的条件下,评价了方法的可靠性。15种PAHs在0.01～10 μg/L范围内呈良好的线性关系,相关系数r均不小于0.9913,峰面积的相对标准偏差(RSD)在2.3%～4.7%之间(n=6)。在优化条件下,富集因子和萃取回收率良好,分别为674～1032和67.4%～103.2%,15种PAHs的检出限(S/N=3)在0.0003～0.002 μg/L之间。建立的方法应用于敖江水样中PAHs的检测,平均加标回收率在79.5%～92.3%之间,RSD在4.3%～6.7%范围内(n=5)。该方法适用于环境水样中痕量PAHs的分析。     

中空纤维液相微萃取-高效液相色谱法测定纺织品中10种含氯苯酚类化合物

建立了中空纤维液相微萃取-高效液相色谱法测定纺织品中10种含氯苯酚类化合物的方法。系统地优化了影响萃取效率的因素,得到的最佳萃取条件为：萃取溶剂为正己烷,接受相NaOH溶液的浓度为0.10 mol/L,萃取时间为60 min,搅拌速度为600 r/min。在最佳萃取条件下,10种含氯苯酚在0.01～1.00 mg/L范围内线性关系良好（r>0.999）,10种含氯苯酚的检出限（信噪比为3）为0.01 mg/kg,富集倍数为95～101。在空白样品中添加0.01、0.05和0.1 mg/kg 3个不同水平的10种含氯苯酚类化合物,其平均回收率为78.8%～105.1%,相对标准偏差为0.3%～7.3%。研究结果表明该方法灵敏度高、简便、准确,可用于纺织品中含氯苯酚类化合物的测定。     

中空纤维三相液相微萃取-高效液相色谱法测定环境水样中7种苯氧羧酸类除草剂

建立了利用中空纤维三相液相微萃取-高效液相色谱联用技术(HF-LPME-HPLC)同时测定环境水中痕量麦草畏(dicamba)、氟草烟(fluroxypyr)、4-氯苯氧乙酸(4-CPA)、2甲4氯(MCPA)、2,4-滴(2,4-D)、2,4-滴苯氧丁酸(2,4-DB)和2甲4氯苯氧丁酸(MCPB)等7种苯氧羧酸类除草剂的分析方法。考察了萃取剂﹑接受相和给出相pH值、萃取时间﹑搅拌速度和盐效应等对检测的影响,通过正交试验优化萃取条件,得到的最佳萃取条件为正辛醇作萃取剂,给出相pH为3,接受相pH为12,萃取30 min,搅拌速度400 r/min。结果表明7种除草剂在较宽的线性范围内线性良好,相关系数为0.9953～0.9988,检出限(信噪比为3)为0.2～1.0 μg/L,富集倍数为76.7～121,加标回收率为68%～104%,相对标准偏差为3.2%～8.1%。该法灵敏度高、操作简单、检测快速、有机溶剂消耗少,为环境水样中痕量苯氧羧酸类除草剂残留的分析提供了有益的参考。     

Determination of diethylhexyl phtalate in water by solid phase microextraction coupled to high performance liquid chromatography

Difficulties detected in the determination of the diethylhexylphthalate (DEHP) at trace levels by gas chromatography–mass spectrometry (GC–MS) using SPME, due to its ubiquitous distribution in the environment has been overcome and a new method for the determination of DEHP in drinking water has been proposed. The method is based on solid phase microextraction (SPME) coupled to high-performance liquid chromatography (HPLC). Detection was carried out spectrophotometrically. Calibration graph was linear in the range 10–110 μg/L with a regression coefficient of r² = 0.998 and a detection limit of 0.6 μg/L. The relative standard deviation was 5 and 2% (n = 4) for chromatographic areas and retention times, respectively. The usefulness of the SPME–HPLC technique was confirmed.     

一次性固相微萃取-高效液相色谱法测定环境水样中的3种多环芳烃

以涂有聚二甲基硅氧烷(PDMS)的石英光导纤维作为固相微萃取纤维,建立了一次性固相微萃取与高效液相色谱联用测定环境水样中的菲、荧蒽和屈3种多环芳烃(PAHs)的方法。实验考察了解吸时间、萃取时间、搅拌速度、盐效应以及样品溶液pH值对萃取效率的影响,优化得到的萃取和解吸条件为: 于60 mL样品溶液中放入两段萃取纤维(1.5 cm)和1.2 g氯化钠,在1200 r/min搅拌速度下萃取60 min,取出萃取纤维并转入120 μL甲醇中密封静置解吸24 h后,取20 μL解吸液进行液相色谱测定。该方法对于菲、荧蒽和屈的检出限分别为0.17、0.17和0.08 μg/L;精密度(以测定0.5 μg/L PAHs标准溶液6次的相对标准偏差计)小于8%;实际样品中3种PAHs的加标回收率为80.0%～107%。该方法快速简便,纤维一次性使用,克服了污染物在纤维上残留的问题。     

Determination of formaldehyde in shiitake mushroom by ionic liquid-based liquid-phase microextraction coupled with liquid chromatography

Using ionic liquid as extraction solvent and 2,4-dinitrophenylhydrazine (DNPH) as derivative agent, formaldehyde in shiitake mushroom was determined by liquid-phase microextraction coupled with high-performance liquid chromatography (HPLC). Shiitake mushroom was leached with water and filtrated, then the formaldehyde in filtrate was derivatized with DNPH and extracted simultaneously into a 10 μl drop of ionic liquid suspended on the tip of the microsyringe, and finally injected into the HPLC system for determination. The proposed procedure has a detection limit of 5 μg l⁻¹ formaldehyde in extraction solution, thus the mushroom sample filtrate could be diluted with a large ratio to eliminate the influence of sample matrix. The method has a relative standard deviation of 3.5% between days for 53.5 μg l⁻¹ formaldehyde standards. High contents of formaldehyde (119-494 μg g⁻¹ wet weight), which is harmful for human beings, were detected in shiitake mushroom. Therefore, strategies must be taken to prevent the accumulation and strictly control the content of formaldehyde in shiitake mushroom.     

Determination of phenols in waters by stir membrane liquid-liquid-liquid microextraction coupled to liquid chromatography with ultraviolet detection

A simple and rapid method for the determination of eleven phenols in water samples is presented. The target analytes are isolated by stir membrane liquid-liquid microextraction working under the three-phase mode. An alkaline aqueous solution is used as extractant phase while octanol is selected as supported liquid membrane solvent. The target analytes are separated and determined by liquid chromatography (LC) with ultraviolet detection (UV). All the variables involved in the extraction process have been studied in depth. Low detection limits (in the range from 82.1 ng/L for phenol to 452 ng/L for 2,4,5-trichlorophenol) were obtained. The repeatability, expressed as relative standard deviation (RSD), varied between 1.3% (for 4-nitrophenol) and 8.0% (for 4-chlorophenol). The enrichment factors were in the range from 168 (for 2,4,5-trichlorophenol) to 395 (for 3-chlorophenol). The proposed procedure was applied for the direct determination of the eleven phenols in some real water samples including river, well and tap waters. The accuracy was evaluated by means of a recovery study, the results being in the range of 87-120%.     

固相微萃取-高效液相色谱联用测定环境水样中双酚A的自由溶解态浓度

应用可忽略耗损固相微萃取与高效液相色谱联用技术测定了环境水样中双酚A的自由溶解态浓度。为了获得高的灵敏度并减小环境因素（如温度和搅拌等）的影响,采用商品化固相微萃取纤维CW／TPR进行平衡采样。在环境水样常见pH（5～8）、缓冲容量（5～200mmol／L）和盐度（0～500mmol／L）条件下,4h可以达到萃取平衡。100mL样品足以避免样品耗损。以配制在250mmol／L NaCl和125mmol／L磷酸盐溶液（pH6．4）中的双酚A标准溶液进行校准,可以将缓冲液（0～200mmol／L）、盐度（0～500mmol／L）和pH（5．7～8．5）的影响控制在15％偏差范围以内。如需更准确的测定,也可以对样品pH值的影响加以校正。pH为6．4时,方法的线性范围为0．1～250μg／L,检出限为0．03μg／L,相对标准偏差（5μg/L,n=3）为1．1％。采用本方法测定了污水处理厂排水口的双酚A的自由溶解态浓度。     

分散液液微萃取-衍生化高效液相色谱-荧光检测法测定环境水样中4种酚类内分泌干扰物

为实现小体积环境水样中酚类化合物的准确、快速、高灵敏测定,通过分散液液微萃取(DLLME)和荧光衍生化的结合,建立了高效液相色谱-荧光检测(HPLC-FLD)双酚A、壬基酚、辛基酚和对特辛基酚的分析方法。考察并优化了DLLME和衍生化条件,结果表明,最优的DLLME条件为萃取剂氯仿用量70μL,分散剂乙腈用量400μL,漩涡振荡3 min,高速离心2 min。以2-[2-(7 H-二苯并[a,g]咔唑-乙氧基)]-乙基氯甲酸酯(DBCEC-Cl)为柱前衍生试剂,在pH10.5的Na2CO3-NaHCO3缓冲液/乙腈溶液、50℃下衍生反应3 min得到稳定的衍生产物,于10min内实现了4种酚衍生物的分离。方法的检出限为0.9~1.6 ng/L,定量限为3.8~7.1 ng/L,具有良好的线性、精密度和回收率,与以往报道的方法相比具有一定的优势和实用性,可用于造纸厂废水、湖水、生活废水、自来水中4种酚类内分泌干扰物的测定。     

Determination of atrazine, desethyl atrazine and desisopropyl atrazine in environmental water samples using hollow fiber-protected liquid-phase microextraction and high performance liquid chromatography

A new method based on hollow fiber-protected liquid-phase microextraction (LPME) was developed for the simultaneous determination of atrazine, desethyl atrazine and desisopropyl atrazine in environmental water samples. In LPME, analytes were extracted into 1-octanol immobilized in the micropores of a poly(vinylidene fluoride) porous hollow fiber membrane, and back extracted into the acceptor (4 M HCl) filled in the lumen of the hollow fiber. After LPME, the analytes trapped in the acceptor were analyzed with high-performance liquid chromatography after neutralization. The effect of extraction factors such as sample pH, acceptor pH, salinity, extraction time, stirring rate, and humic acid were studied. Under the optimized conditions, the limits of detection and relative standard deviations were respectively in the range of 0.5–1.0 μg L⁻¹ and 3.9–4.7% (n = 5). The proposed method was applied to determine atrazine, desethyl atrazine and desisopropyl atrazine in wastewater and groundwater samples. The three analytes were below the limits of detection, but good relative spiked recoveries over 90.1 ± 5.9% at 5 μg L⁻¹ spiked level were obtained.     

Determination of ultraviolet filters in environmental water samples by temperature-controlled ionic liquid dispersive liquid-phase microextraction

In the present study, a rapid, highly efficient and environmentally friendly sample preparation method named temperature-controlled ionic liquid dispersive liquid-phase microextraction (TC-IL-DLPME), followed by high performance liquid chromatography (HPLC) was developed for the extraction, preconcentration and determination of four benzophenone-type ultraviolet (UV) filters (viz. benzophenone (BP), 2-hydroxy-4-methoxybenzophenone (BP-3), ethylhexyl salicylate (EHS) and homosalate (HMS)) from water samples. An ultra-hydrophobic ionic liquid (IL) 1-hexyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate ([HMIM][FAP]), was used as the extraction solvent in TC-IL-DLPME. Temperature served two functions here, the promotion of the dispersal of the IL to the aqueous sample solution to form infinitesimal IL drops and increase the interface between them and the target analytes (at high temperature), and the facilitation of mass transfer between the phases, and achievement of phase separation (at low temperature). Due to the ultra-hydrophobic feature and high density of the extraction solvent, complete phase separation could be effected by centrifugation. Moreover, no disperser solvent was required. Another prominent feature of the procedure was the combination of extraction and centrifugation in a single step, which not only greatly reduced the total analysis time for TC-IL-DLPME but also simplified the sample preparation procedure. Various parameters that affected the extraction efficiency (such as type and volume of extraction solvent, temperature, salt addition, extraction time and pH) were evaluated. Under optimal conditions, the proposed method provided good enrichment factors in the range of 240–350, and relative standard deviations (n = 5) below 6.3%. The limits of detection were in the range of 0.2–5.0 ng/mL, depending on the analytes. The linearities were between 1 and 500 ng/mL for BP, 5 and 1000 ng/mL for BP-3, 10 and 1000 ng/mL for HMS and 5 and 1000 ng/mL for EHS. Finally, the proposed method was successfully applied to the determination of UV filters in swimming pool and tap water samples and acceptable relative recoveries over the range of 88.0–116.0% were obtained.     

超声辅助分散液液微萃取-高效液相色谱测定水样中的4种邻苯二甲酸酯类增塑剂

建立了采用超声辅助分散液液微萃取技术结合高效液相色谱法(UA-DLLME-HPLC)对4种邻苯二甲酸酯(PAEs)进行富集、检测的方法,并成功应用于实际水样分析。实验中采用富集因子来评价萃取效率,考察并优化了影响萃取效率的主要因素,包括萃取剂类型和用量、分散剂类型和用量、超声时间、离子强度、萃取时间和pH值等。结果表明: 在最佳萃取条件下,该法对4种PAEs（邻苯二甲酸二甲酯、邻苯二甲酸二乙酯、邻苯二甲酸二丁酯和邻苯二甲酸二正辛酯）具有较高的富集能力,富集因子分别为71、144、169和159;检出限分别为3.78、1.77、3.07和3.30 μg/L。对实验室自来水、某品牌矿泉水以及湖水分别加标50、200及500 μg/L的回收率为82.99%～114.47%,相对标准偏差为1.93%～8.31%。该法简便、快速、环保,可以用于测定实际水样中的PAEs类增塑剂。     

固相微萃取高效液相色谱法测定食品中己烯雌酚

建立了固相微萃取(SPME)-高效液相色谱(HPLC)联用测定食品中己烯雌酚(DES)的方法.考察了萃取纤维头、萃取时间、解吸时间和盐的添加对萃取效果的影响.在此基础上,采用正交试验,以解析液组成、萃取液pH和搅拌速度为3因素筛选出了最佳固相微萃取条件.该分析方法的线性范围为0.02 ～2.0μg/ml,工作曲线线性良...     

Application of liquid-phase microextraction for the determination of phoxim in water samples by high performance liquid chromatography with diode array detector

A new method, which involves liquid-phase microextraction (LPME) followed by high performance liquid chromatography (HPLC) with diode array detector (DAD), was developed to determine phoxim in water sample. Experimental parameters affecting the extraction efficiency, such as extraction solvent, solvent volume, agitation speed of the sample and extraction time were investigated. Under the optimal extraction conditions, phoxim was found to yield a good linear calibration curve in the concentration range from 0.01 to 5 μg mL⁻¹. The limit of detection (LOD) is 10 ng mL⁻¹, and relative standard deviation (RSD) at the 100 ng mL⁻¹ levels is 8.4%. Lake water and tap water samples were successfully analyzed using the proposed method.