共查询到19条相似文献,搜索用时 109 毫秒
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离子液体是在室温或近于室温下呈液态的熔盐体系,由特定阳离子和阴离子构成。与传统的液态物质相比,离子液体几乎没有蒸气压、不易挥发、能溶解许多无机物和有机物。在样品前处理技术中得到了广泛的应用。微萃取技术是一种简便快速、提取效率高、溶剂用量少、环境友好的样品前处理技术。本文综述了离子液体在微萃取技术(液相微萃取和固相微萃取)中的应用。 相似文献
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对化学毒剂及其降解产物的分析检测是准确鉴别化学沾染的重要手段。由于化学毒剂及其降解产物的样品可能存在于各种基质中,且部分化学毒剂在水体等基质中降解速度过快,所以将痕量样品从复杂基质中快速高效的富集提取出来显得尤其重要。微萃取技术具有装置体积小、使用少量或不使用溶剂、绿色环保、易与色谱分析技术联用等突出优势受到广泛的关注,并且在含化学毒剂环境样品的前处理过程中得到大量的应用。本文介绍了基于固相和液相萃取剂的多种微萃取技术,并综述了固相微萃取和液相微萃取技术应用于化学毒剂及其降解产物检测方面的研究进展。 相似文献
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固相微萃取萃取头制备技术及试验方法的进展 总被引:15,自引:0,他引:15
在阐述固相微萃取的平衡理论及非平衡理论基础上,重点探讨了萃取头的制备技术和相关试验方法的进展。除了介绍商品化通用萃取头的制备技术外,还论述了溶胶-凝胶法、电沉积法、碳素基体吸附法、高温环氧树脂固定法等新的制备技术;探讨了固相微萃取试验方法中萃取模式和萃取头的选择、萃取条件优化以及方法的灵敏度、精度、自动化等的评价;进一步总结了固相微萃取的应用现状,对固相微萃取的发展方向作了展望。 相似文献
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分散液液微萃取技术在食品分析中的应用进展 总被引:3,自引:0,他引:3
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。 相似文献
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液相微萃取研究与应用 总被引:4,自引:0,他引:4
液相微萃取是近年来新兴的一种微型化样品前处理技术。该技术集萃取、净化、浓缩于一体,具有溶剂耗量少、成本低廉、操作便捷、精确和灵敏度高的特点。本文全面深入地综述了液相微萃取的各种工作模式及其原理和特点,阐述了相关的联用分析技术和方法的适用性,归纳和分析了影响萃取的主要影响因素及优化的方法,突出了上述几方面中具有发展潜力的新进展,包括各种动态萃取模式与装置、 与其它技术联用的新策略、离子液体作为萃取溶剂等,详细总结了近年来液相微萃取技术在环境、药物和食品等分析领域中的应用情况。 相似文献
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样品制备与处理的进展——无溶剂萃取技术 总被引:12,自引:0,他引:12
本文讨论了现代分析化学的重要领域之一, 样品制备及前处理技术的进展--无溶剂萃取技术。包括气相萃取、超临界流体萃取、膜萃取、固相萃取、固相微萃取等方法。简述了这些方法的原理及其应用, 探讨了样品制备与前处理技术的发展动向。 相似文献
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Recent developments in solid-phase microextraction for on-site sampling and sample preparation 总被引:1,自引:0,他引:1
Chunfeng DuanZheng Shen Dapeng WuYafeng Guan 《Trends in analytical chemistry : TRAC》2011,30(10):1568-1574
On-site sampling and sample preparation favor portable, solventless or even solvent-free techniques. Solid-phase microextraction (SPME) has these advantages. This review focuses on developments between 2007 and early 2011 in microextraction techniques for on-site sampling and sample preparation, including fiber SPME, stir-bar sorptive extraction (SBSE), thin-film microextraction (TFME) and different types of in-needle SPME. The major trends in on-site applications of SPME appear to be fiber and thin-film SPME, microextraction by packed sorbent (MEPS) and the sorbent-packed needle-trap device (NTD). We discuss and compare several aspects of these types of SPME in on-site applications. We also describe sorbent phases for SPME that benefit on-site applications. Finally, we provide a perspective on SPME-based techniques for on-site applications. 相似文献
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Guohui Wei Yanyan Li 《International journal of environmental analytical chemistry》2013,93(6):397-408
Two liquid-phase microextraction (LPME) approaches, static direct-immersed single-drop microextraction (DI-SDME) and continuous-flow microextraction (CFME), were used to extract methomyl in water samples and their respective extraction efficiencies were compared. Several important parameters affecting extraction efficiency such as the type of extraction solvent, solvent drop volume, stirring speed or flow rate, extraction time and salt concentration were optimised. The optimised conditions were as follows: 3.0-µL tetrachloroethane (C2H2Cl4) as the extraction solvent, 15% NaCl (w/v), 15 min extraction time and stirring speed at 600 rpm for DI-SDME; 3.5-µL C2H2Cl4 as the extraction solvent, 15% NaCl (w/v), 21 min extraction time and flowing rate at 0.8 mL min?1 for CFME. Under the previous optimal conditions, the linear range, detection limit (S/N = 3) and precision (RSD, n = 6) were 5.0-5000 ng mL?1, 1.5 ng mL?1, 6.9% for DI-SDME, and 4.0–10000 ng mL?1, 2.5 ng mL?1, 4.6% for CFME, respectively. Lake and river water samples were successfully analysed by DI-SDME and CFME. The result demonstrated that both SDME and CFME techniques are simple, low cost and amity to environment. As a result, the two approaches have tremendous potential in trace analysis of methomyl in natural waters. 相似文献
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Guizhen Li 《Separation & Purification Reviews》2018,47(1):1-18
Microextraction is considered as one of the most critical steps in the entire analytical process because it can effectively remove interference and pre-concentrate the target analytes. Molecularly imprinted polymers (MIPs) are synthetic polymers with a predetermined selectivity for a given analyte, or group of structurally related compounds, which are excellent materials for sample preparation in the process of microextraction owing to their high selectivity and ability. This review provides a critical overview of the synthesis and characterization of MIPs, with a focus on recent applications in the field of solid-phase microextraction (SPME) and liquid-phase microextraction (LPME). The advantages and drawbacks of the applications of MIPs used in SPME and LPME as well as the future expected trends are also discussed. 相似文献
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Ali Sarafraz-Yazdi Seyed-Hadi Khaleghi-Miran Zarrin Es’haghi 《International journal of environmental analytical chemistry》2013,93(14-15):1036-1047
In the present work the determination of benzene, toluene, ethylbenzene and o-xylene (BTEX) in environmental sample solutions using gas chromatography with flame ionisation detection (GC-FID) combined with three different sampling techniques, such as; direct single drop microextraction (DI-SDME), headspace single drop microextraction (HS-SDME) and ultrasonic assisted HS-SDME, were compared. In all of these techniques, for the determination of BTEX, the experimental parameters such as organic solvent effect, extraction time, agitation speed and salting effect were optimised. At their optimised conditions of operation the detection limits, times of extraction and precision for the three techniques are established. A detailed comparison of the analytical performance characteristics of these techniques for final GC-FID determination of BTEX in water samples was given. The technique provided a linear range of 50–20000?ng?mL–1 for DI-SDME and 10–20000?ng?mL–1 for HS-SDME methods, good repeatability (RSDs <4.72–7.74% for DI-SDME and 1.80–7.05% for HS-SDME (n?=?5), good linearity (r?≥?0.9978) and limits of detection (LODs) in the range of 0.006–10?ng?mL?1 for DI-SDME, 0.1–3?ng?mL–1 for HS-SDME methods (S/N?=?3). Then the optimised techniques were also applied to real samples (river and waste waters) containing BTEX and similar precision (RSD?<?8.2,?n?=?3) was obtained. 相似文献
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Growing concerns related to antibiotic residues in environmental water have encouraged the development of rapid, sensitive, and accurate analytical methods. Single-drop microextraction has been recognized as an efficient approach for the isolation and preconcentration of several analytes from a complex sample matrix. Thus, single-drop microextraction techniques are cost-effective and less harmful to the environment, subscribing to green analytical chemistry principles. Herein, an overview and the current advances in single-drop microextraction for the determination of antibiotics in environmental water are presented were included. In particular, two main approaches used to perform single-drop microextraction (direct immersion-single-drop microextraction and headspace-single-drop microextraction) are reviewed. Furthermore, the impressive analytical features and future perspectives of single-drop microextraction are discussed in this review. 相似文献
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Cristina Mahugo-SantanaZoraida Sosa-Ferrera Mª Esther Torres-PadrónJosé Juan Santana-Rodríguez 《Trends in analytical chemistry : TRAC》2011,30(5):731-748
Liquid-liquid extraction (LLE) has been widely used as a pre-treatment technique for separation and preconcentration of organic analytes from aqueous samples. Nevertheless, this technique has several drawbacks, mainly in the use of large volumes of solvents, making LLE an expensive, environmentally-unfriendly technique.Miniaturized methodologies [e.g., liquid-phase microextraction (LPME)] have arisen in the search for alternatives to conventional LLE, using negligible volumes of extracting solvents and reducing the number of steps in the procedure. Developments have led to different approaches to LPME, namely single-drop microextraction (SDME), hollow-fiber LPME (HF-LPME), dispersive liquid-liquid microextraction (DLLME) and solidified floating organic drop microextraction (SFODME).This overview focuses on the application of these microextraction techniques to the analysis of emerging pollutants. 相似文献
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Martina Havlikova Radomir Cabala Vera Pacakova Miroslava Bursova Zuzana Bosakova 《Journal of separation science》2019,42(1):273-284
Sample pretreatment techniques or preconcentration constitute a very important step before the analysis of environmental, clinical, pharmaceutical, and other complex samples. Thanks to extraction techniques it is possible to achieve higher method sensitivities and selectivities. Miniaturization microextraction methods make them more environmentally friendly and only small amounts of samples are required. In the past 30 years, a number of microextraction methods have been developed and used and are documented in thousands of articles. Many reviews have been written focusing on their use in specified professional fields or on the latest trends. Unfortunately, no uniform nomenclature has been introduced for these methods. Therefore, this review attempts to classify all the essential microextraction techniques and describes their advantages, disadvantages, and the latest innovations. The methods are divided into two main groups: single drop and sorbent‐based techniques according to the type of extraction phase. 相似文献
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毛细管电泳(CE)具有分析速度快、分离效率高、样品消耗少、成本低廉等优点,已被应用于无机离子、有机小分子、蛋白质、核酸及细胞等的分析中。CE中最常用的检测方式是紫外检测(UV),但由于常规进样样品体积小、检测光程短,CE-UV的灵敏度往往不能满足复杂样品中痕量物质直接分析的要求。CE中的在柱富集技术包括堆积、动态pH界面、吹扫和瞬间等速电泳等,可在很大程度上提高CE-UV的检测灵敏度;另外,固相和液相微萃取技术及其与在柱富集技术相结合应用在CE中也能净化样品基质,进一步提高富集倍数,改善分析灵敏度,从而拓宽了CE-UV在复杂样品分析中的应用范围。 相似文献