Temperature-controlled ionic liquid dispersive liquid phase microextraction combined with ultra-high-pressure liquid chromatography for the rapid determination of triclosan,triclocarban and methyl-triclosan in aqueous samples

As extraction solvents,ionic liquids have green characteristics.In this study,an environmentally benign analytical method termed temperature-controlled ionic liquid dispersive liquid phase microextraction (TIL-DLME) combined with ultra-highpressure liquid chromatography (UHPLC)-tunable ultraviolet detection (TUV) was developed for the pre-concentration and determination of triclosan (TCS),triclocarban (TCC) and methyl-triclosan (M-TCS) in water samples.Significant parameters that may affect extraction efficiencies were examined and optimized,including the types and amount of ionic liquids,volume of the diluent,heating temperature,cooling time,salt effect and pH value.Under the optimum conditions,linearity of the method was observed in the ranges of 0.0100-100 μgL-1 for TCS and M-TCS,and 0.00500-50.0 μgL-1 for TCC with correlation coefficients (r2) 】 0.9903.The limits of detection (LODs) ranged from 1.15 to 5.33 ngL-1.TCS in domestic water and TCC in reclaimed water were detected at the concentrations of 1.01 and 0.126 μgL-1,respectively.The spiked recoveries of the three target compounds in reclaimed water,irrigating water,waste water and domestic water samples were obtained in the ranges of 68.4%-71.9%,61.6%-87.8%,58.9%-74.9% and 64.9%-92.4%,respectively.Compared with the previous dispersive liquid-liquid microextraction method (DLLME) about the determination of TCS,TCC and M-TCS,this method is not only more environmentally friendly but also more sensitive.

Ionic liquid based dispersive liquid-liquid microextraction of aromatic amines in water samples

In this work, a new microextraction method termed ionic liquid based dispersive liquid-liquid microextraction （IL-DLLME） was demonstrated for the extraction of 2-methylaniline, 4-chloroaniline, 1-naphthylamine and 4-aminobiphenyl in aqueous matrices. After extraction the ionic liquid （IL） phase was injected directly into the high performance liquid chromatography （HPLC） system for determination. Some parameters that might affect the extraction efficiency were optimized. Under the optimum conditions, good linear relationship, sensitivity and reproducibility were obtained. The limits of detection （LOD, S/N = 3） for the four analytes were in the range of 0.45-2.6 μg L^-1. The relative standard deviations （R.S.D., n = 6） were in the range of 6.2-9.8%. This method was applied for the analysis of the real water samples. The recoveries ranged from 93.4 to 106.4%. The main advantages of the method are high speed, high recovery, good repeatability and volatile organic solvent-free.

Evaluation of Response Surface Methodology in Dispersive Liquid-Liquid Microextraction for Lead Determination Using Ionic Liquids

This paper describes a dispersive liquid–liquid microextraction (DLLME) procedure using room temperature ionic liquids (RTILs) coupled with flame atomic absorption spectrometry detection with microsample intro-duction system capable of quantifying trace amounts of lead. In the proposed approach, ammonium pyr-rolidine dithiocarbamate (APDC) was used as a chelating agent and 1-hexyl-3-methylimmidazolium bis (trifluormethylsulfonyl)imid as an extraction solvent was dissolved in acetone as the disperser solvent. The binary solution was then rapidly injected by a syringe into the water sample containing Pb2+ complex. Some factors influencing the extraction efficiency of Pb2+ and its subsequent determination, including extraction and dispersive solvent type, pH of sample solution, concentration of the chelating agent and salt effect were inspected by a full factorial design to identify important parameters and their interactions. Next, a central composite design was applied to obtain the optimum points of the important parameters. Under the optimum conditions, the limit of detection (LOD) was 0.2 μg/L. The relative standard deviation (R.S.D) was 1.4% for 5 μg/L of Pb2+ (n = 7). The relative recovery of lead in seawater, blood, tomato and black tea samples was measured.

Determination of seven active components in Salvia miltiorrhiza herb by matrix solid phase dispersion combined with ion liquid extraction followed by high performance liquid chromatography

A low cost,rapid and sensitive preparation method of silica gel supported ionic liquid(SGSIL)combined with matrix solid phase dispersion(MSPD)followed by high performance liquid chromatography(HPLC)with ultraviolet detection(UV)is proposed,and it was applied to determine the seven active compounds in Salvia Miltiorrhiza herb.SGSIL and ionic liquid[BMIM]BF4 were used as the adsorbent and the green elution reagent in the MSPD procedure.Several extraction conditions including type of filler and elution solvent,the volume of elution solvent,material liquid ratio were optimized.Under the optimum conditions,the SGSIL-MSPD-HPLC method showed a low limit of detection(LOD,S/N=3)of 0.0122-0.8788μg/mL for standard solution,limit of quantification(LOQ,S/N=10)of 0.0406-2.9292μg/mL for standard solution,wide linear range from 1.56 to 2000μg/mL for all compounds for standard solution,correlation coefficients(r)of more than 0.9990,acceptable reproducibility(relative standard deviations,RSDs<3.54%),and precision of RSDs<3.36%for intra-day,RSDs<3.50%for inter-day.The satisfactory recoveries ranged from 96.4 to 102.5,with RSDs less than 3.45%.The developed SGSIL-MSPD method is easier and more suitable for the determination of the seven active compounds in Salvia Miltiorrhiza herb than the traditional ultrasonic extraction.It was an effective and efficient method for the extraction and quantification of the seven active compounds in traditional Chinese herbal samples.

Trace determination of hexabromocyclododecane diastereomers in water samples with temperature controlled ionic liquid dispersive liquid phase microextraction

A novel temperature controlled ionic liquid dispersive liquid phase microextracfion （TCIL-DLPME） coupled with rapid resolution liquid chromatography-electrospray tandem mass spectrometry （RRLC-ESI-MS-MS） has been developed for the enrichment and determination of three hexabromocyclododecane diastereomers （HBCDs） in water samples. Green solvent ionic liquid （IL） was used as extraction solvent instead of toxic organic solvents. This technique also avoided the usage of dispersive solvent. Some important parameters that might affect the extraction efficiency were optimized. Under the optimum conditions, good linear relationship, sensitivity and reproducibility were obtained. All the limits of detection for the three diastereomers were 0.1 ng/ mL. The linear range was obtained in the range of 1-100 ng/mL for the total amount of three HBCD diastereomers. It was satisfactory to analyze real environmental water samples with the recoveries ranging from 77.2% to 99.3%. The main advantage of the method is toxic organic solvent-free.

Combination of ionic liquid dispersive liquid-phase microextraction and high performance liquid chromatography for the determination of triazine herbicides in water samples

A temperature-controlled ionic liquid dispersive liquid-phase microextraction in combination with high performance liquid chromatography was developed for the enrichment and determination of triazine herbicides such as cyanazine,simazine,and atrazine in water samples.1-Octyl-3-methylimidazolium hexafluorophosphate（[C8MIM][PF6]） was selected as the extraction solvent.Several experimental parameters were optimized.Under the optimal conditions,the linear range for cyanazine was in the concentration range of 0.5–80 mg/L and the linear range for simazine and atrazine was in the range of1.0–100 mg/L.The limit of detection（LOD,S/N = 3） was in the ranges of 0.05–0.06 mg/L,and the intra day and inter day precision（RSDs,n = 6） was in the ranges of 3.2%–6.6% and 4.8%–8.9%,respectively.Four real water samples were analyzed with the developed method,and the experimental results showed that the spiked recoveries were satisfactory.All these exhibited that the developed method was a valuable tool for monitoring such pollutants.

Synthesis of a Novel Imidazole Ionic Liquid Modified Mesoporous Silica SBA15 for Selective Separation and Determination of Inorganic Arsenic in Rice

A novel 1-methylimidazole ionic liquid modified SBA15 mesoporous silica(1-MIIL@SBA15) was synthesized and applied to selective separation of inorganic arsenic(iAs) in rice by dispersive solid phase extraction(DSPE), followed by hydride generation-atomic fluorescence spectrometric(HG-AFS) quantification. The prepared sorbent was characterized by FTIR, FESEM, BET and Zeta potential. Key parameters of adsorption and desorption in DSPE were optimized using standard reference material 1568 b rice flour. Under optimal conditions, the limit of detection was 8.776 ng/kg, relative standard deviation was ≤2.0%, and recoveries of iAs were in the 92.3～94.4% range. This method was successfully applied to the determination of iAs in rice. Under acidic condition, the electrostatic interaction between the positively charged 1-MIIL@SBA15 and anionic iAs played an important role in selective iAs separation, rendering this method suitable for iAs analysis.

Orthogonal array optimization of ionic liquid based dispersive liquid-liquid microextraction for toxic anilines in foods

A simple and rapid method of ionic liquid based dispersive liquid-liquid microextraction （DLLME） combining with high performance liquid chromatography （HPLC） was developed for the analysis of four toxic anilines in flour steamed bread and maize steamed bread. Several possible influential factors such as the type of ionic liquid and disperser solvent, extraction time, sample pH, ionic strength and the volume of ionic liquid and disperser solvent were optimized using single factor experiments and orthogonal array design （OAD） with OA25（54） matrix. Analysis of variance （ANOVA） and percent contribution （PC） were used to investigate the significance of the factors of OAD. Sample pH and ionic strength are statistically demonstrated two chief factors. Under the optimum condition, the method exhibits a good linearity （r2 〉 0.99） over the studied range （50-1000 ng g-l） for anilines. The extraction factors and recoveries for the anilines in two kinds of steamed breads ranged between 34.1%-73.3% and 44.3%-95.3%, respectively. The limit of detections （LODs） and limit of quantitations （LOQs） ranged be- tween 10-15 ng g-1 and 30--45 ng g-1.

Dispersive liquid–liquid microextraction of silver nanoparticles in water using ionic liquid1-octyl-3-methylimidazolium hexafluorophosphate

Using the ionic liquid（IL）1-octyl-3-methylimidazolium hexafluorophosphate as the extractant and methanol as the dispersion solvent,a dispersive liquid–liquid microextraction method was developed to extract silver nanoparticles（AgN Ps）from environmental water samples.Parameters that influenced the extraction efficiency such as IL concentration,pH and extraction time were optimized.Under the optimized conditions,the highest extraction efficiency for AgN Ps was above 90% with an enrichment factor of 〉90.The extracted AgN Ps in the IL phase were identified by transmission electron microscopy and ultraviolet–visible spectroscopy,and quantified by inductively coupled plasma mass spectrometry after microwave digestion,with a detection limit of 0.01 μg/L.The spiked recovery of AgN Ps was 84.4% with a relative standard deviation（RSD）of 3.8%（n = 6）at a spiked level of 5 μg/L,and 89.7% with a RSD of 2.2%（n = 6）at a spiked level of 300 μg/L,respectively.Commonly existed environmental ions had a very limited influence on the extraction efficiency.The developed method was successfully applied to the analysis of Ag NPs in river water,lake water,and the influent and effluent of a wastewater treatment plant,with recoveries in the range of 71.0%–90.9% at spiking levels of 0.11–4.7 μg/L.

Optimization and Application of Liquid Chromatography Determination of Dispersive Liquid-liquid Microextraction Purified Astaxanthin in Shrimp Waste

A new molecularly imprinted solid-phase extraction（MISPE） monolithic cartridge was synthesized, and MISPE-DLLME（DLLME=dispersive liquid-liquid microextraction） was developed for purification of astaxanthin in shrimp waste. The eluent（methanol） from MISPE was used as the dispersive solvent in subsequent DLLME for further purifying and enriching the analyte prior to high-performance liquid chromatography（HPLC） analysis. The mobile phase was methanol-acetonitrile-water-dichloromethane（85：5：5：5, volume ratio）, flow rate was 0.7 mL/min and UV wavelength was 476 nm. Under optimal conditions, good linearity was obtained in a range of 0.2--200.0 lug/mL（r2=0.9998） with a limit of detection（LOD） of 0.08 Hg/mL, and the extraction recoveries at three spiked levels ranged from 88.3%--92.5% with a relative standard deviation（RSD） less than 4.3%. Moreover, the mean contents of astaxanthin in the three batches of shrimp waste were 95.9, 85.4 and 77.2 μg/g, respectively. This method combining the advantages of MISPE and DLLME results in high selectivity and low cost, which was applied to determining the astaxanthin level in shrimp waste samples.

磁性分散固相微萃取/UHPLC-Q-Orbitrap HRMS测定运动营养食品中27种氨基酸

基于磁性分散固相微萃取净化,建立了测定运动营养食品中27种氨基酸含量的超高效液相色谱-四极杆-静电场轨道阱高分辨质谱法。通过优化液相色谱条件、质谱条件和样品前处理过程,在20 min内实现了对27种目标物的测定。样品经涡旋振荡,超声提取,磁性氧化石墨烯分散固相微萃取净化,采用Thermo Accucore HILIC色谱柱分离,以0.1%甲酸水溶液(含5.0 mmol/L甲酸铵)和0.1%甲酸乙腈(含5.0 mmol/L甲酸铵)为流动相进行梯度洗脱,静电场轨道阱高分辨质谱检测,外标法定量。结果表明,27种目标化合物在一定质量浓度范围内线性良好,相关系数(r^(2))均大于0.99,方法的定量下限为0.10~0.25 mg/kg,平均回收率为70.0%~93.0%,日内相对标准偏差(RSD,n=6)为1.6%~10%,日间RSD(n=5)为1.4%~5.2%。该方法高效灵敏,准确可靠,适用于运动营养食品中27种氨基酸的测定。

离子液体-分散液液微萃取结合高效液相色谱法快速分析茯苓中氰戊菊酯和联苯菊酯农药残留

离子液体-分散液液萃取法被成功地应用于萃取和富集中药材茯苓中氰戊菊酯和联苯菊酯。1-辛基-3-甲基咪唑六氟磷酸盐([C_8mim][PF_6])作为萃取溶剂,1-丁基-3-甲基咪唑四氟硼酸盐([C_4mim][BF_4])为分散剂。整个萃取过程不需要加入任何有机溶剂,萃取过程快速,3min内就可以达到萃取平衡。茯苓中目标化合物的加样回收率在95.7%~98.3%之间,检出限为0.50和0.40 ng·mL^(-1)之间,结果令人满意,说明该实验方法适用于检测中药材中氰戊菊酯和联苯菊酯农药残留。

抽拔辅助分散固相微萃取技术用于饮料中5种杀菌剂残留检测研究

为了快速检测葡萄汁和苹果汁两种果汁,以及绿茶和红茶两种茶饮料样品中嘧菌酯、三唑酮、百菌清、嘧菌环胺和肟菌酯5种杀菌剂的残留,本研究开发了一种绿色、经济易行的抽拔辅助分散固相微萃取方法,通过在β-环糊精/坡缕石上涂覆离子液体,制备了一种新型的萃取材料,并设计了一系列针对目标杀菌剂萃取条件的优化试验,采用液相色谱检测。结果表明:在萃取材料为40 mg、洗脱液丙酮为600μL、进行6次分散循环、7次洗脱循环的条件下,化合物的检出限(LOD)为0.03~0.38μg/L,定量限(LOQ)为0.09~1.15μg/L,富集因子为121~201。对于5种杀菌剂,可检测的线性范围为5~500μg/L,决定系数(R2)在0.9982~0.9999之间,回收率在91%~102%之间。该方法具有较高的精密度和正确度。实际样品测试结果表明,抽拔辅助分散固相微萃取技术可用于饮料中杀菌剂残留的萃取。

基于双阳性离子液体-原位转化盐析增强型微萃取技术在液体基质宽极性激素类污染物检测中的应用

本研究利用亲水性双阳性离子液体[C_(6)(MIM)_(2)]Br_(2),以丙酮作为双功能溶剂,LiNTf_(2)作为亲-疏水转化试剂,开发了一种基于原位转化双阳性离子液体的盐析增强型分散微萃取方法,实现了离子液体一次萃取,可同时高效富集和提取多种宽极性激素和酚类污染物的目的。该方法成功地应用于检测环境水样和人体尿样中7种宽极性(logK_(ow)=1.61~5.00)激素和酚类污染物,对7种目标物(氢化可的松、雄烯二酮、雌酮、炔雌醇、雌二醇、三氯生及双酚Z)的检出限为0.028~0.43μg/L,加标回收率为72.5%~112.7%,相对标准偏差(RSD)在2.8%~6.2%。本研究可减少环境水样及尿液样品检测的工作量,是一种绿色、高效和简易的宽极性污染物前处理方法,在复杂液体基质样品领域显示出较好的应用前景。

分散液液微萃取-气相色谱法测定水样中甲拌磷农药

建立了基于分散液液微萃取（DLLME）的新型样品前处理方法,并采用气相色谱/氢火焰离子化检测器对水样中痕量的甲拌磷农药进行了测定。考察了影响分散液液微萃取的因素包括萃取溶剂、分散剂、样品体积、萃取温度和离心速度等。在最佳实验条件下,对甲拌磷的富集倍数达到300倍;检出限为0.001μL/L;方法的线性范围为0.01-10μL/L,R^2为0.9986;相对标准偏差为6.65%;回收率为104%。将分散液液微萃取法与单滴液相微萃取和离子液体-液相微萃取方法进行了对比,结果表明,分散液液微萃取技术具有操作简单、快捷（前处理时间小于5 min）、富集效果好、回收率高等优点。同时预言,将离子液体与分散液液微萃取结合,将会产生更加满意的结果。

基于离子液体的液相微萃取-高效液相色谱法测定水中有机磷农药

建立了基于1-丁基-3-甲基咪唑六氟磷酸盐离子液体的液相微萃取-高效液相色谱分析水样中甲拌磷、对硫磷和辛硫磷的方法。考察了萃取溶剂、萃取溶剂与样品溶液体积比、萃取时间、萃取温度和搅拌速度对液相微萃取的影响。在优化的萃取条件下,甲拌磷、对硫磷、辛硫磷3种农药的富集倍数分别为665、630和553倍;方法有好的线性范围(0.01-1μL/L)和低的检出限(0.001-0.01μL/L,S/N=3)。对0.1μL/L的甲拌磷,对硫磷和辛硫磷测定3次的相对标准偏差分别为3.44%、10.50%和2.41%。

离子液体-液相微萃取-高效液相色谱法测定纺织品中芳香胺

建立了一种基于1-丁基-3-甲基咪唑六氟磷酸盐离子液体的溶剂棒液相微萃取样品前处理技术，结合高效液相色谱法分析染色纺织品中源于禁用偶氮染料的8种致癌芳香胺的方法。考察了有机萃取溶剂、给出相pH值、搅拌速度、盐效应和萃取时间的影响，确定了以正辛醇为有机萃取溶剂，离子液体为接收相，给出相pH值为10并添加饱和NaCl溶液，搅拌速率为1000r／min，萃取时间为40min的芳香胺优化萃取条件。方法的线性范围宽，相关系数r〉0．9986；检出限为0．014～2．1μg／L（S／N=3）；相对标准偏差〈4．6％（n=10）；回收率为83．2％～91．2％；8种芳香胺的富集倍数在10～270倍之间。本法具有灵敏，萃取效率高，有机溶剂消耗少，操作简单、快捷等特点。

磁性石墨烯固相萃取-分散液液微萃取-气相色谱法测定水和绿茶中酰胺类除草剂残留

采用磁性石墨烯纳米复合材料作为磁性固相萃取剂进行磁性固相萃取,再进行分散液液微萃取,采用气相色谱建立了高灵敏测定环境水样和绿茶中5种酰胺类除草剂残留的方法。对影响萃取效率的诸因素进行了优化。在优化条件下,5种酰胺类除草剂的富集倍数在3399～4002之间,甲草胺、乙草胺、异丙甲草胺、丁草胺和丙草胺浓度在0.1～50μg/L范围内与峰面积呈良好的线性关系,线性相关系数在0.9973～0.9993之间,检出限在0.01～0.03μg/L范围内。本方法应用于河水、自来水和绿茶样品的分析,平均加标回收率在80.2%～108.4%之间,相对标准偏差在3.8%～5.8%之间。本方法操作简单、灵敏、富集倍数高。

温控离子液体分散液液微萃取结合高效液相色谱法检测脐橙中染色剂残留

建立了QuEChERS-温控离子液体分散液液微萃取结合高效液相色谱法快速检测脐橙中5种染色剂残留的分析方法。 QuEChERS前处理步骤：样品用乙腈快速提取,NaCl 和无水MgSO4除水后,经N-丙基乙二胺净化。温控离子液体分散液液微萃取步骤：QuEChERS前处理的净化液（1 mL）为分散剂,1-辛基-3-甲基咪唑六氟磷酸盐离子液体（60μL）为萃取剂,55℃水浴12 min,将目标物富集。用高效液相色谱-紫外检测器分析,检出样品用超高效液相色谱-串联质谱确证。在0.01和0.05 mg/kg的添加水平下,5种染色剂的平均回收率为70.3%～93.6%,相对标准偏差为3.5%～9.2%,定量限为1.1～2.8μg/kg。

离子液体分散液相微萃取-高效液相色谱法测定番茄中的氨基甲酸酯类农药

将离子液体1-丁基-3-甲基咪唑六氟磷酸盐([BMIm][PF6])作为萃取剂,采用分散液相微萃取-高效液相色谱法分析番茄样品中的4种氨基甲酸酯类农药残留,并考察了不同缓冲溶液浓度、pH值及萃取时间等因素对分散液相微萃取效果的影响。在优化实验条件下,该方法对涕灭威、克百威、甲萘威、异丙威的富集倍数分别为317、430、545、625,且具有良好的线性范围(0.01～10mg/L)和较低的检出限(0.12～0.43μg/L),对涕灭威、克百威、甲萘威、异丙威测定5次的相对标准偏差为5.3%～5.5%,用于示范区采集的番茄样品分析,平均加标回收率为75%～120%。研究表明[BMIm][PF6]可有效地萃取番茄中的氨基甲酸酯类农药残留,具有萃取效率高、灵敏度高、操作简单、绿色环保等优点,可以满足番茄样品中氨基甲酸酯类农药残留的检测要求。