悬浮固化液相微萃取技术研究进展

悬浮固化液相微萃取集采样、萃取、浓缩于一体,具有富集效率高、成本低、有机溶剂用量少,易与气相色谱(GC)、高效液相色谱(HPLC)、原子吸收分光光度仪(AAS)联用等特点,是一种环境友好的样品前处理新技术.本文对悬浮固化液相微萃取的基本原理、影响萃取率的因素和目前的应用研究进展进行了简要评述.     

基于中空纤维的液相微萃取技术的研究进展

基于中空纤维的液相微萃取集采样、萃取、浓缩于一体,具有成本低,溶剂用量少,易与高效液相色谱、气相色谱、毛细管电泳联用等特点。该技术不仅可实现较高的回收率和富集效率,而且具有突出的样品净化功能,是一种环境友好的样品前处理新技术。该文对基于中空纤维的液相微萃取的装置、操作模式、基本原理及近年来应用研究的进展进行了综述。     

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,R2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。     

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.     

分散液相微萃取-气相色谱法检测尿中的三种苯并二氮杂(革)类药物

建立了分散液相微萃取与气相色谱电子捕获法检测尿中三种苯并二氮杂(革)类药物的方法.对影响萃取富集效率的因素进行优化,萃取条件选定为:将0.75 mL含有35 μL氯苯的甲醇混合溶液快速注入到5.0mL样品溶液中,分散混匀后,以4000 r/min离心4min,吸取有机相直接进样分析.在优化条件下,三种药物在1～400μ...     

分散液液微萃取技术在食品分析中的应用进展

近年来,分散液液微萃取作为一种新型液相微萃取(LPME)技术受到广泛关注。该技术具有操作简单、有机溶剂用量少、富集倍数高等显著优点,已被广泛用于各类样品基质中无机和有机分析物的提取。但由于传统分散液液微萃取技术的萃取剂以高毒性有机溶剂为主,且选择性差,从而严重限制了该技术的应用。为此,最近几年发展了许多操作模式,如低密度萃取剂分散液液微萃取、悬浮固化分散液液微萃取、调节萃取剂密度的分散液液微萃取、离子液体-分散液液微萃取、水溶液作为萃取剂的反相分散液液微萃取等。该文综述了分散液液微萃取技术原理、萃取过程和影响因素(如萃取剂与分散剂种类和体积、p H值、离子强度、萃取时间等),并对其在食品分析中的应用进展进行了系统总结。     

分散液-液微萃取技术在污染物分析中的应用

分散液-液微萃取技术是一种新型的、具有巨大潜力的样品前处理技术,已经越来越多地被应用到多种污染物的富集过程中。此方法具有简单、快速、价格低廉、环境友好、回收率和富集倍数高等优点。近年来,作为一种可行的分析技术,分散液-液微萃取技术获得了持续的关注和广泛应用。该文综述了分散液-液微萃取技术的研究进展及其在不同介质污染物分析中的应用。     

食品及食品包装材料中光引发剂分析方法的研究进展

综述了食品及食品包装材料中光引发剂分析方法的研究进展,包括样品的前处理方法(如固相萃取、固相微萃取、基质分散固相萃取、加速溶剂萃取、分散液液微萃取、凝胶渗透色谱)和分析方法(如气相色谱-质谱法、气相色谱-串联质谱法、液相色谱法、液相色谱-串联质谱法、超高效合相色谱法),并对其发展趋势作了展望。     

在线固相萃取/高效液相色谱法测定环境水样中的4种痕量邻苯二甲酸酯

建立了一种在线固相萃取/高效液相色谱测定水样中4种痕量邻苯二甲酸酯(邻苯二甲酸甲酯、邻苯二甲酸乙酯、邻苯二甲酸丁酯和邻苯二甲酸(2-乙基)己酯)的新方法.样品由外加泵注入一根固相萃取小柱上进行富集,再将富集柱切换至高效液相色谱系统中,将富集在固相萃取小柱的邻苯二甲酸酯洗脱至分析柱进行分析.在线固相萃取柱为IonPac(...     

多孔中空纤维液相微萃取技术的研究进展

基于多孔中空纤维的液相微萃取集采样、萃取和浓缩于一体,具有成本低,易与多种分析仪器联用等特点,该技术不仅可得到较高的富集倍数和回收率,而且具有突出的样品净化功能,有机溶剂用量非常少,是一种环境友好的样品前处理新技术,国内尚未广泛应用。本文综述了多孔中空纤维液相微萃取的主要装置、萃取模式、影响因素及其应用,引用文献54篇。     

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.     

Evolution of dispersive liquid–liquid microextraction method

Dispersive liquid–liquid microextraction (DLLME) has become a very popular environmentally benign sample-preparation technique, because it is fast, inexpensive, easy to operate with a high enrichment factor and consumes low volume of organic solvent. DLLME is a modified solvent extraction method in which acceptor-to-donor phase ratio is greatly reduced compared with other methods. In this review, in order to encourage further development of DLLME, its combination with different analytical techniques such as gas chromatography (GC), high-performance liquid chromatography (HPLC), inductively coupled plasma-optical emission spectrometry (ICP-OES) and electrothermal atomic absorption spectrometry (ET AAS) will be discussed. Also, its applications in conjunction with different extraction techniques such as solid-phase extraction (SPE), solidification of floating organic drop (SFO) and supercritical fluid extraction (SFE) are summarized. This review focuses on the extra steps in sample preparation for application of DLLME in different matrixes such as food, biological fluids and solid samples. Further, the recent developments in DLLME are presented. DLLME does have some limitations, which will also be discussed in detail. Finally, an outlook on the future of the technique will be given.     

分散液液微萃取技术及其在生物样品分析中的研究进展

分散液液微萃取是一种新型微萃取技术,具有易操作、低成本、耗时短、环境友好、萃取效率高等优点。该文着眼于分散液液微萃取技术中萃取剂的性质及辅助分散方式,综述了常规分散液液微萃取、离子液体分散液液微萃取、超声辅助分散液液微萃取等多种萃取模式,并重点归纳总结了近5年分散液液微萃取技术在生物样品分析领域的应用进展。     

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。     

Dispersive liquid–liquid microextraction in food analysis. A critical review

An extensive critical evaluation of the application of dispersive liquid–liquid microextraction (DLLME) combined with chromatographic and atomic-spectroscopic methods for the determination of organic and inorganic compounds is presented. The review emphasizes the procedures used for the prior treatment of food samples, which are very different from the DLLME procedures generally proposed for water samples. The main contribution of this work in the field of DLLME reviews is its critical review of the abundant literature showing the increasing interest and practical advantages of using DLLME and closely related microextraction techniques for food analysis.     

Application of dispersive liquid-liquid microextraction for the determination of aflatoxins B1, B2, G1 and G2 in cereal products

The application of dispersive liquid-liquid microextraction (DLLME) technique for the rapid analysis of aflatoxins B(1), B(2), G(1) and G(2) in maize, rice and wheat products has been evaluated. After extraction of aflatoxins from cereal matrices with a mixture of methanol/water 8:2 (v/v), the analytes were rapidly transferred from the extract to another small volume of organic solvent, chloroform, by DLLME. Aflatoxins were determined using high performance liquid chromatography with florescence detection and photochemical post-column derivatization. Parameters affecting both extraction and DLLME procedures, such as extraction solvent, type and volume of DLLME extractant, volume of water and salt effect, were systematically investigated and optimized to achieve the best extraction efficiency. Under the optimal experimental conditions, the whole analytical method provides enrichment factors around 2.5 times and detection limits (0.01-0.17 μg kg(-1)) below the maximum levels imposed by current regulation for aflatoxins in cereals and cereal products intended for direct human consumption. Recoveries (67-92%) and repeatability (RSD<10, n=3), tested in three different cereal matrices, meet the performance criteria required by EC Regulation No. 401/2006 for the determination of the levels of mycotoxins in foodstuffs. The proposed method was successfully applied to the analysis of retail cereal products with quantitative results comparable to the immunoaffinity chromatography (IAC). The main advantages of developed method are the simplicity of operation, the rapidity to achieve a very high sample throughput and low cost.     

Recent developments in dispersive liquid–liquid microextraction

During the past 7 years and since the introduction of dispersive liquid–liquid microextraction (DLLME), the method has gained widespread acceptance as a simple, fast, and miniaturized sample preparation technique. Owing to its simplicity of operation, rapidity, low cost, high recovery, and low consumption of organic solvents and reagents, it has been applied for determination of a vast variety of organic and inorganic compounds in different matrices. This review summarizes the DLLME principles, historical developments, and various modes of the technique, recent trends, and selected applications. The main focus is on recent technological advances and important applications of DLLME. In this review, six important aspects in the development of DLLME are discussed: (1) the type of extraction solvent, (2) the type of disperser solvent, (3) combination of DLLME with other extraction methods, (4) automation of DLLME, (5) derivatization reactions in DLLME, and (6) the application of DLLME for metal analysis. Literature published from 2010 to April 2013 is covered.     

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.     

Dispersive liquid-liquid microextraction

Dispersive liquid-liquid microextraction (DLLME) is a novel sample-preparation technique offering high enrichment factors from low volumes of water samples. It has found wide acceptance because of several advantages, including simplicity, low cost and ease of method development, which made it available to virtually all analytical laboratories.This review focuses on improvements made in DLLME since its introduction in 2006. We present use of DLLME with simultaneous derivatization of analytes and connection of DLLME to other sample-preparation techniques. We also describe exchange of toxic chlorinated solvents with low toxic hydrocarbons, alcohols and ionic liquids.We include application of DLLME to pre-concentration of metal ions and many more modifications of this newly developed technique. We briefly describe different applications of DLLME to several groups of analytes, including pesticides, pharmaceuticals, phenols and other compounds, and, finally, we predict some future trends.     

超声波辅助分散液相微萃取-气相色谱联用分析菌核净

将超声波萃取(USE)与分散液-液微萃取(DLLME)联合,利用气相色谱-电子捕获检测(GC-ECD),建立了一种高灵敏度检测水体中菌核净的新方法。对萃取的条件进行优化,选定萃取条件为:在5 mL样品中,注入1 mL丙酮和0.1 mL的四氯化碳混合液,20 Hz超声10 min,振荡混匀后高速离心5 min,移出下层溶剂低温吹干以丙酮定容自动进样分析。在优化条件下,样品的富集倍数可达50倍,检出限为0.001μg/mL,对采于蔬菜地边的水样进行加标回收率实验,平均回收率在81%以上,相对标准偏差在4.3%~7.6%之间,方法可满足水样中菌核净农药残留的检测要求。