共查询到19条相似文献,搜索用时 92 毫秒
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作为一种简单、高效、低耗的预富集方法,气相富集技术(GPE)可作为原子光谱仪器的关键部件用以提高分析灵敏度、消除基体干扰,在原子光谱的小型化、现场化研究领域已得到广泛应用。GPE是通过氢化物发生、紫外蒸气发生、电热蒸发等进样方式使样品转换为气态分析物,被石英、碳、金属等材料捕获在富集装置中,其中捕获/释放条件也是决定元素预富集的关键因素,主要包括冷捕获、合金捕获、热捕获、介质阻挡放电等富集/释放方式。该文综述了GPE技术在原子光谱领域的研究进展,从进样方式、捕获材料、捕获/释放方式等方面进行了分析与探讨,并对其研究和应用前景进行了展望。 相似文献
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评述了近年来原子光谱法测定润滑油中金属含量技术的沿革、方法及进展。着重介绍了原子光谱法测定润滑油中金属含量的样品前处理方法及原子光谱法测定技术。 相似文献
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固相微萃取技术在农药残留分析中的应用 总被引:1,自引:0,他引:1
固相微萃取技术是一种崭新的无溶剂萃取分离技术。文中对影响萃取效果的因素进行了综述,并对固相微萃取技术在农药残留分析中的应用作出概述,引用文献56篇。 相似文献
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环境水样及食品中亚硝酸根的分析进展 总被引:5,自引:1,他引:5
评述了自1997年至2002年国内外环境水样及食品中亚硝酸根(NO2^-)的分析进展。包括分子光谱法、电化学分析法和色谱分析法,引用文献96篇。 相似文献
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The purpose of this review is to discuss the strategic problems of automating sample preparation (SP) for high performance liquid chromatography (HPLC). There is a general feeling that SP is the bottleneck of many HPLC procedures. Despite numerous reports of successful automation of SP, there are still many laboratories using manual or semiautomated SP procedures. This calls for a reevaluation of the present situation. 相似文献
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建立了一种微乳液毛细管电动色谱(MEEKC)-场放大富集(FASI)分析尿液中多种麻醉剂(吗啡、可待因、纳洛酮、海洛因、蒂巴因、可卡因、哌替啶、芬太尼、美沙酮)的方法。考察了微乳液组成、分离电压等因素的影响,得到的最佳微乳液组成(质量分数)为0.6%十二烷基硫酸钠、1.2%正丁醇、0.6%乙酸乙酯和97.6% 10 mmol/L硼砂缓冲液(pH 9.5);分离电压为25 kV。在上述微乳体系中,9种化合物在15 min内得到了基线分离。采用场放大在线富集技术提高了分析灵敏度,检出限(S/N=3)低至0.3 μg/L。模拟尿样样品中9种麻醉剂的加标回收率介于79.4%~119.9%之间,日内相对标准偏差小于5.5%。将该方法应用于美沙酮大鼠体外代谢样品的测定,结果令人满意。 相似文献
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Hans Fredrik Veiteberg Braaten Heleen A. de Wit Christopher Harman Ulla Hageström Thorjørn Larssen 《International journal of environmental analytical chemistry》2013,93(4):381-384
Despite an increasing focus on low level methods for determination of mercury species in water over the last decades, few studies have paid attention to direct effects of different sample preparation methods (i.e. preservation techniques) on natural freshwater samples. In this study we show how different preservation techniques give significantly different concentrations of total and methylmercury in freshwaters (9 and 14% on average, respectively). Natural stream samples from a forested lake catchment were studied. Mean stream sample concentrations of total (3.6 ng/L) and methylmercury (0.06 ng/L) reflect levels typical for pristine humic boreal catchments. The main reason for the observed average differences in total and methylmercury concentrations is the use of one instead of two sample bottles and timing of sample acidification, respectively. 相似文献
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Carrier ampholyte-free isoelectric focusing (IEF) sample injection (concentration) for capillary electrophoresis (CE) is realized in a single capillary. A short section of porous capillary wall was made near the injection end of a capillary by HF etching. In the etching process, an electric voltage was applied across the etching capillary wall and electric current was monitored. When an electric current through the etching capillary was observed, the capillary wall became porous. The etched part was fixed in a vial, where NaOH solution with a certain concentration was added during the sample injection. The whole capillary was filled with pH 3.0 running buffer. The inlet end vial was filled with protein sample dissolved in the running buffer. An electric voltage was applied across the inlet end vial and etched porous wall. A neutralization reaction occurs at the boundary (interface) of the fronts of H+ and OH-. A pH step or sharp pH gradient exists across the boundary. When positive protein ions electromigrate to the boundary from the sample vial, they are isoelectricelly focused at points corresponding to their pH. After a certain period of concentration, a high voltage is applied across the whole capillary and a conventional CE is followed. An over 100-fold concentration factor has been easily obtained for three model proteins (bovine serum albumin, lysozyme, ribonuclease A). Furthermore, the IEF sample concentration and its dynamics have been visually observed with the whole-column imaging technique. Its merits and remaining problem have been discussed, too. 相似文献
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Sempere J. Nomen N. Serra E. de Armas D. 《Journal of Thermal Analysis and Calorimetry》2003,72(2):415-420
The Similarity Match, Distance Match, Discriminant Analysis, Search Standards, and QC Compare Search techniques of statistical
analysis are applied to DSC records in order to distinguish between two forms or classes of a new pharmaceutical active component.
The classes are defined according to its therapeutic activity as 'positive' and 'negative'. Excellent results are obtained
using the QC Compare Search Method.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献