固相萃取-分散液液微萃取-柱前衍生法测定水样中痕量雌激素

建立了碳纳米管的固相萃取-分散液液微萃取-柱前荧光衍生化(SPE-DLLME-PFD)测定水体中痕量雌三醇(E3)、双酚A(BPA)、17α-乙炔基雌二醇(EE2)及17β-雌二醇(E2)的高效液相色谱方法.采用中心复合设计和响应曲面法分析并优化SPE、DLLME及PLD条件,最佳条件为210 mL水样以2.0 mL/min的流速过固相萃取柱(碳纳米管量30 mg),甲醇洗脱,氮气浓缩并定容至0.6 mL(分散剂),将100 μL C6MIM[PF6]与分散剂的混合液注入到NaCl含量为25％的2.0 mL去离子水中,离心,移取20 μL下层有机相于样品瓶中,与4.0 mg衍生剂混合,在40℃水浴中衍生25 min;用0.1mL甲醇溶解过量的衍生剂颗粒,取20 μL进样分析.在优化条件下.4种雌激素的线性范围为0.05～5.00 μg/L,相关系数R2=0.9966～0.9999;,检出限介于0.13～6.33 ng/L(S/N=3)之间.不同加标浓度条件下,雌激素的加标回收率在83.1％～122.4％范围内(RSD=1.7％～9.6％).在实际水样中E3和BPA检出率较高.与其它方法相比,本方法虽然萃取时间长、水样量大、步骤多,但具有检出限低、操作简便、环境友好等优点.     

分散液-液微萃取/高效液相色谱法测定水样中的痕量双酚A

建立了分散液-液微萃取与高效液相色谱联用技术测定水样中痕量双酚A(BPA)的方法. 通过对实验条件的筛选及优化, 得到最佳条件: 22.5 μL氯苯作萃取剂、0.5 mL丙酮作分散剂、0 min静止萃取时间、调节pH 3.2左右、10%离子强度及9 mL水样体积. 此条件下方法的线性范围为0.5~100 μg/L(R2=0.9941), 检出限为0.10 μg/L. 在BPA质量浓度为1 μg/L条件下, 方法回收率为87.8%~111.0%, 相对标准偏差8.3%(n=5), 富集倍数范围1905~2527. 对添加不同BPA浓度的自来水、地表水及回用中水进行分析, 回收率分别为(108±11.1)%, (107±13.2)%及(81.2±6.2)%(n=3). 在既定的色谱条件下, BPA的测定不受乙炔基雌二醇、雌二醇、雌三醇、雌酮和壬基酚等雌激素的干扰.     

环境水样中己烯雌酚与双烯雌酚的离子液体分散液-液微萃取/高效液相色谱法测定

以离子液体([Omim][PF6])为萃取剂,采用冷诱导分散液-液微萃取对环境水样中的己烯雌酚和双烯雌酚残留进行富集.优化后的萃取条件:在pH 3.0的条件下,以50 μL离子液体为萃取剂,0.8 mL甲醇为分散剂,采用反相 Extend-C18柱(5 μm, 250 mm×4.6 mm),流动相为水-甲醇(体积比40 ∶ 60),流速:1.0 mL/min,柱温:35 ℃,检测波长:245 nm.在优化的萃取条件下,己烯雌酚和双烯雌酚的线性范围均为2.5 ～200 μg/L,检出限(S/N=3)为80 ng/L.应用于环境水样中己烯雌酚和双烯雌酚的检测,加标回收率为93% ～98%,相对标准偏差为3.0% ～5.4%,建立的方法简单、环保.     

凝固-漂浮分散液液微萃取-高效液相色谱法测定水样中氯酚

采用凝固-漂浮分散液液微萃取(SFO-DLLME)-高效液相色谱法测定水样中3种氯酚.以密度小于水,且凝固点为24 ℃的1-十二醇为萃取剂,甲醇为分散剂,对水样进行分散液液微萃取.将混合液离心,再通过冷冻凝固操作使漂浮的萃取剂和水相分离,萃取剂复溶后进样测定.本实验确定的最佳实验条件为:萃取剂200 μL、分散剂300 μL、1.2 g NaCl、1 mol/L H3PO4 200 μL、样品体积8.0 mL、萃取时间3 min.3种氯酚测定的线性范围为0.05～6.0 mg/L;检出限为20～38 μg/L.应用本方法分析实际水样,加标回收率在90.11%～107.7%之间;日间相对标准偏差在3.5%～4.6%之间.本方法扩展了分散液液微萃取萃取剂的选择范围,具有简便、快速、准确、环境友好等特点.     

分散液液微萃取-高效液相色谱法测定环境水样中2,4-二氯酚

建立了简便、快速、有效的分散液液微萃取-高效液相色谱法测定环境水样中2,4-二氯酚的分析方法。对萃取剂、分散剂的种类和体积、萃取时间、离心时间、盐浓度等影响萃取效率的因素进行了优化。方法的线性范围为1～500μg/L(r=0.9997),相对标准偏差(RSD)为3.8%(n=6),检出限为0.19μg/L。该法适用于环境水样中的痕量2,4-二氯酚的检测。     

原位衍生分散液相微萃取-气相色谱-质谱快速测定水中的四溴双酚A

通过研究萃取剂、分散剂的种类和体积,KHCO3用量,衍生剂乙酸酐的用量和萃取时间对萃取效率的影响,建立了原位衍生分散液相微萃取-气相色谱质谱联用测定水中四溴双酚A的方法.方法线性范围:0.5～ 100 μg/L,检出限:0.1μg/L;RSD:5.4％ (n =5).将该方法用于环境水样的测定,加标回收率:53.5％ ...     

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。     

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。     

有机悬浮固化分散液-液微萃取测定水样中痕量铅

建立了以二乙基二硫代氨基甲酸钠为配位剂,十二醇为萃取剂,乙醇为分散剂的悬浮固化分散液-液微萃取—火焰原子吸收光谱法测定水样中痕量铅的方法。详细探讨了影响萃取效率的因素。优化条件为:二乙基二硫代氨基甲酸钠的用量为10-6 mol,十二醇体积为90.00μL,乙醇体积为1.00 mL,pH为7.00。在最佳条件下,铅的检出限为1.12μg/L,富集倍率为16.00,线性范围5.00～600.00μg/L,对含有20.00μg/L和600.00μg/L Pb的标准溶液平行萃取测定11次,测定结果的RSD分别为3.73%和2.62%。本方法应用于自来水、河水及海水中痕量铅的分析,加标回收率为90.10%～100.70%。     

表面活性剂辅助-凝固-漂浮分散液液微萃取/高效液相色谱法测定环境水样中酚类化合物

建立了表面活性剂辅助-凝固-漂浮分散液液微萃取(SA-DLLME-SFO)/高效液相色谱法同时测定环境水样中4种酚类化合物的分析方法。SA-DLLME-SFO实验中选用十二醇为萃取剂,Tween 20为分散剂,考察了萃取剂和非离子表面活性剂的体积、萃取时间、离心时间和盐效应等因素对萃取效率的影响。结果表明:对硝基苯酚、对甲酚、对溴酚和双酚A的检出限分别为0.13,0.13,1.02,0.25 ng/m L;对硝基苯酚、对甲酚和双酚A的线性范围为2~4 000 ng/m L,对溴苯酚的线性范围为10~4 000 ng/m L;加标浓度为0.2,0.8μg/m L时,4种酚类化合物的回收率为96.6%~105%,相对标准偏差(RSD,n=5)为1.9%~4.9%。该方法可用于池塘水和湖水等天然水体中对硝基苯酚、对甲酚、对溴酚和双酚A的测定。     

分散固相萃取-分散液液微萃取/高效液相色谱法测定西瓜中氟唑菌酰羟胺残留

采用分散固相萃取和分散液液微萃取联用的方法,建立了高效液相色谱快速检测西瓜中氟唑菌酰羟胺残留的分析方法。使用乙腈和水混合溶液作为萃取溶剂,经N-丙基-乙二胺硅烷(PSA)固相萃取吸附剂净化提取液,分散液液微萃取将目标物富集到1,1,2,2-四氯乙烷溶剂中,采用高效液相色谱进行分析。考察了萃取溶剂的种类与体积、分散剂体积及盐浓度等因素对分散液液微萃取萃取效率的影响。结果表明:分析物的质量浓度在0.01~5 mg/L范围内与峰面积的线性关系良好,相关系数(r)为0.999 9,定量下限(S/N=10)为0.01 mg/kg。加标水平为0.01、0.1、1 mg/kg时,平均回收率为89.2%~94.5%,相对标准偏差(n=5)为3.0%~8.7%。该方法简单、高效、灵敏度高,适用于西瓜中氟唑菌酰羟胺的残留检测。     

分散液-液微萃取与气相色谱-质谱联用分析环境水样中痕量的2,4-二硝基甲苯和磷酸三(2-氯乙基)酯

建立了分散液-液微萃取与气相色谱-质谱联用同时测定环境水样中痕量2,4-二硝基甲苯和磷酸三(2-氯乙基)酯的新方法。对影响萃取效率的因素进行了详细的考察和优化,确定采用的最佳萃取条件为: 将0.8 mL乙醇和60 μL氯仿的混合溶液快速注入5.0 mL的样品溶液中,振动混匀120 s后,离心分离,吸取沉积在试管底部的氯仿相直接进样分析。该方法对磷酸三(2-氯乙基)酯和2,4-二硝基甲苯的检出限(信噪比为3)分别为0.01和0.04 μg/L,富集倍数分别为96.6和127.5;两种物质的线性范围达3到4个数量级;日内和日间测定的相对标准偏差(RSDs, n=6)分别为8.6%～11.5%和8.9%～12.0%。将该方法用于环境水样中2,4-二硝基甲苯和磷酸三(2-氯乙基)酯的分析,其加标回收率为102.1%～110.9%。方法具有操作简单、方便快速、灵敏度高、无交叉污染和环境友好等优点。     

Development of an ionic liquid-based dispersive liquid-liquid micro-extraction method for the determination of phthalate esters in water samples

Ionic liquid-based dispersive liquid-liquid micro-extraction (IL-DLLME) was coupled with high-performance liquid chromatography-ultraviolet (HPLC-UV) for the determination of four phthalate esters, including butyl benzyl phthalate, di-n-butyl phthalate, dicyclohexyl phthalate and bis(2-ethylhexyl) phthalate in water samples. The mixture of ionic liquid (IL) and dispersive solvent was rapidly injected into 10 mL aqueous sample. Then, IL phase was separated by centrifugation and was determined by high-performance liquid chromatography-ultraviolet. The factors influencing the extraction efficiency, such as type and volume of IL, disperse solvent, extraction time, centrifuging time and ionic strength, were investigated and optimized. Under the optimized conditions, the extraction recoveries by the proposed ionic liquid-based dispersive liquid-liquid micro-extraction for the four phthalates ranged from 83.0 to 91.7%. The relative standard deviations were between 7.8 and 15%. The limits of quantification for four phthalates were between 10.6 and 28.5 μg/L. The proposed method was successfully applied for the analysis of PAEs in tap, lake and treated wastewater samples.     

基于分子络合的分散液液微萃取与高效液相色谱联用检测环境水样中2种苯氧羧酸类除草剂

建立了基于分子络合的分散液液微萃取（DLLME）方法,以磷酸三丁酯为萃取剂,以甲醇为分散剂,与高效液相色谱联用检测了环境水样中麦草畏和2,4-二氯苯氧乙酸（2,4-D酸）2种苯氧羧酸类除草剂,对影响前处理效果的因素（包括水样的pH值、萃取剂的种类和体积、分散剂的种类和体积、反萃液的pH值、反萃液的体积和盐浓度等）进行了详细考察,在最佳萃取条件下（水样体积10 mL,水样的pH值为0~1.0、100 μL磷酸三丁酯萃取剂、1000 μL甲醇分散剂、0.01 mol/L的氢氧化钾反萃液的体积为80 μL）,2种苯氧羧酸类除草剂在0.50~1000 μg/L范围内具有良好的线性,相关系数不小于0.9985,麦草畏和2,4-D酸的检出限分别为0.44 μg/L和0.49 μg/L,富集倍数分别为85和90,在实际样品中的加标回收率为75.7%~104.0%。该方法基于分子络合反应机理,将新型萃取剂磷酸三丁酯应用于分散液液微萃取,与HPLC联用实现了麦草畏和2,4-D酸的富集与检测,为环境水样中苯氧羧酸类除草剂的检测提供了新的前处理方法。     

Simple, rapid, and sensitive determination of beta-blockers in environmental water using dispersive liquid-liquid microextraction followed by liquid chromatography with fluorescence detection

A novel method, dispersive liquid-liquid microextraction combined with liquid chromatography-fluorescence detection is proposed for the determination of three beta-blockers (metoprolol, bisoprolol, and betaxolol) in ground water, river water, and bottled mineral water. Some important parameters, such as the kind and volume of extraction and dispersive solvents, extraction time, pH, and salt effect were investigated and optimized. In the method, a suitable mixture of extraction solvent (60 μL carbon tetrachloride) and dispersive solvent (1 mL acetonitrile) were injected into the aqueous samples (5.00 mL) and the cloudy solution was observed. After centrifugation, the enriched analytes in the bottom CCl(4) phase were determined by liquid chromatography with fluorescence detection. Under the optimum conditions, the enrichment factors (EFs) for metoprolol, bisoprolol, and betaxolol were 180, 190, and 182, and the limits of detection (LODs) were 1.8, 1.4, and 1.0 ng L(-1) , respectively. A good linear relationship between the peak area and the concentration of analytes was obtained in the range of 3-150 ng L(-1) . The relative standard deviations (RSDs) for the extraction of 10 ng L(-1) of beta-blockers were in the range of 4.6-5.7% (n = 5). Compared with other methods, dispersive liquid-liquid microextraction is a very simple, rapid, sensitive (low limit of detection), and economical (only 1.06 mL volume of organic solvent) method, which is in compliance with the requirements of green analytical methodologies.     

Dispersive liquid-liquid microextraction based on solidification of floating organic droplet method for the determination of diethofencarb and pyrimethanil in aqueous samples

A dispersive liquid-liquid microextraction method was developed for the determination of fungicides (diethofencarb and pyrimethanil) in aqueous samples. It is based on the use of solidified floating organic drops combined with high-performance liquid chromatography. Extraction solvent and dispersive solvent, extraction time and salt effect were optimized. Under optimized conditions, the enrichment factors for a 5?mL water sample are between 145 and 161. The limits of detection for diethofencarb and pyrimethanil are 0.24 and 0.09???g ? L^?1, respectively. The method offers good repeatability and high recovery. Compared with dispersive liquid-liquid microextraction, it has a higher enrichment factor, high precision due to the ease with which the solidified floating phase is transferred, thus avoiding the loss of analyte. Toxic solvents were replaced by 1-dodecanol with its much lower toxicity. The method has been successfully applied to the determination of the two fungicides in tap water, lake water, and river water.     

漂浮液滴固化分散液液微萃取与高效液相色谱联用检测环境水样中的3种烷基苯酚

建立了漂浮液滴固化分散液液微萃取(DLLME-SFO)方法,以脂肪酸作为萃取剂,以甲醇作为分散剂,与高效液相色谱联用检测了环境水样中3种烷基苯酚。对影响前处理方法的因素进行了详细考察,在最佳萃取条件(60μL萃取剂辛酸、600μL分散剂甲醇、pH值为2.0~8.0、10 mL水样中加入0.5 g NaCl)下,3种烷基苯酚在20~1 500μg/L范围内具有良好的线性关系,相关系数不小于0.998 5,3种目标化合物的检出限为0.45~0.61μg/L,富集倍数为145~169,实际样品中3个水平的加标回收率为80.1%~109.9%。该方法将脂肪酸作为萃取剂,与HPLC联用实现了烷基苯酚的富集与检测,为环境水样中烷基苯酚的检测提供了对环境友好的前处理新方法。     

Extraction optimization of polycyclic aromatic hydrocarbons by alcoholic-assisted dispersive liquid-liquid microextraction and their determination by HPLC

A sensitive method for the extraction and determination of polycyclic aromatic hydrocarbons (PAHs) using alcoholic-assisted dispersive liquid-liquid microextraction (AA-DLLME) and HPLC was developed. The extraction procedure was based on alcoholic solvents for both extraction and dispersive solvents. The effective parameters (type and volume of extraction and dispersive solvents, amount of salt and stirring time) on the extraction recovery were studied and optimized utilizing factorial design (FD) and central composite design (CCD). The best recovery was achieved by FD using 2-ethyl-1-hexanol as the extraction solvent and methanol as the dispersive solvent. The results showed that volume of dispersive solvent and stirring time had no effect on the recovery of PAHs. The optimized conditions were 145 μL of 2-ethyl-1-hexanol as the extraction solvent and 4.2% w/v of salt (NaCl) in sample solution. The enrichment factors of PAHs were in the range of 310-325 with limits of detection of 0.002-0.8 ng/mL. The linearity was 0.01-800 ng/mL for different PAHs. The relative standard deviation (RSD) for intra- and inter-day of extraction of PAHs were in the range of 1.7-7.0 and 5.6-7.3, respectively, for five measurements. The method was also successfully applied for the determination of PAHs in environmental water samples.