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1.
提出了同时测定铜基合金中铝和铁的流动注射分析法。以0.04mol/LHCl作载液,铬天青S为显色剂,通过测定628nm处铝、铁两配合物的吸光度之和及铝配合物的吸光度,实现了两组分的同时测定。在优化的实验条件下,检测限:Al和Fe分别为1.69×10-3和1.73×10-3mg/L,Al浓度在0~0.8mg/L;Fe浓度在0~1.0mg/L时服从比耳定律。进样频率为60样/h,所拟方法用于实际样品分析,获得满意结果。  相似文献   

2.
反向流动注射化学发光法测定痕量铁   总被引:10,自引:1,他引:10  
周延秀  孙杰 《分析化学》1997,25(3):334-337
基于邻菲别名林对高碘酸钾-碱性鲁米诺-铁体系发光强度的增敏作用建立了水体中总铁的反向流动性化学发光检测方法。该法线性范围在1×10^-4-10mg/L,检测限为3×10^-6mg/L,对于5×10^-3mg/L Fe测定9次的相对标准偏差为0.9%。此方法已用在水处理中总铁的监测。  相似文献   

3.
碱性氢化物发生—火焰原子吸收光谱法测定锡   总被引:7,自引:2,他引:7  
对Sn-NaOH-KBH4体系进行了系统研究,采用三乙醇胺-EDTA联合干扰抑制剂,可消除一定量铁及合金元素的干扰,对于锡含量小于0.01%的试样,用苯萃取锡后所有元素不干扰测定。测定液中锡量为0-4μg/10ml,呈线性关系,灵敏度为0.004mg/L/1%,检出限为0.008mg/L,测定钢中大于0.001%锡,结果满意。  相似文献   

4.
介绍了以菲咯嗪-醋酸钠-醋酸缓冲溶液为显色体系、用自制的铁含量比色测定仪快速测定工业用水中总铁含量的方法。总铁含量≤05mg/L时,标准偏差≤003mg/L;总铁含量>05mg/L时,相对标准偏差≤5%。单次测定时间(包括样品处理)为10~15min。采用单色光源及微型流动比色池,由蠕动泵和电子线路实现自动进样,直接显示测定结果。  相似文献   

5.
流动注射—二极管阵列检测分光光度法同时测定铅和镉   总被引:14,自引:0,他引:14  
黎源倩  杨经国 《分析化学》1998,26(7):843-846
建立流动注射-电荷耦合器件二极管阵理分光光度法装置,研究了以meso-四(4-三甲铵苯基)卟啉为显色剂同时测定铅和镉的方法,镉和铅测定的线性范围为0~2.0mg/L和0~2.5mg/L镉的检出限为0.014mg/L,铅为0.015mg/L。进样频率为60次/h,对合成样品和陶瓷食具容器浸泡液中铅和镉进行了同时测定,获得满意的结果,样品的平均标准加入回收率为100.9%,相对标准偏差小于8.8%。  相似文献   

6.
流动注射分析光度法同时测定镍和铁   总被引:7,自引:0,他引:7  
曲祥金  周杰 《分析化学》1997,25(2):168-171
建立了流动注射(FIA)光度法同时测定镍和铁的新方法,以乙酸-乙酸钠缓冲溶液(PH4.50)作载液,溴化十六烷基三甲胺作增溶剂,记录560nm处Ni(Ⅱ)-Br-PADAP与Fe(Ⅱ)-Br-PADAP的峰值吸收之和746nm处Fe(Ⅱ)-Br-PADAP的吸不度测定了钠基合金中的镍和铁。两咱离子的定量线性范围分别为0.10-1.20mg/lL和0.20-1.60mg/L,检出限为0.02mg/L  相似文献   

7.
流动注射分光光度法测定微量硫氰酸根   总被引:2,自引:0,他引:2  
王克太  陈兴国 《分析化学》1998,26(7):836-839
基于3,5-Br2-PADAP硫氰酸根分别与重铬酸根,铈(IV)在硫酸介质中反应成不稳定的蓝色产物,建立了两种测定微量硫氰酸根的流动注射分光光度新方法,在前一方法中,硫氰酸根含量在0.80~7.20mg/L范围内可定量测定,检出限为0.27mg/L在后一方法中,硫氰酸根含量在0.80~6.40mg/L范围内呈线性,检出限为0.30mg/L。当进样体积为100μL时,进样频率为60次/h,所建立的两  相似文献   

8.
液相色谱测定糙米中烯虫酯残留量   总被引:2,自引:0,他引:2  
王超  李淑娟 《分析化学》1998,26(10):1244-1246
研究了液相色谱测定糙米中烯虫酯残留量的方法。试样用丙酮提取,经活性炭,中性氧化铝层析柱一步净化,用液相色谱测定。线性范围0.2-10.0mg/L,检出限为0.05mg/L,当添加浓度0.5-10.0mg/kg时,回收率为84.2%-100.7%之间。用于糙米中烯虫酯残留量检验,结果满意。  相似文献   

9.
双显色剂双波长系数补偿法同时测定铝和铁的研究   总被引:4,自引:0,他引:4  
本文提出了一种双显色双波长系数补偿法测定食品中微量铝、铁的新方法,在pH=6.2缓冲液中,以络天青S为显色剂选择622/506nm波长对测定铝,以5-Br-PADAP为显色剂选择560/660nm波长对测定铁,不经分离可直接测定样品中的铝、铁,铝量在0.2~5.0μg/25ml、铁量在1.0~15.0μg/25ml符合朗伯比耳定律。本法应用于食品中铝、铁测定,得到较满意结果。  相似文献   

10.
本文用抑制型离子色谱,薄壳强碱性阴离子交换树脂为分离柱,柱温为30±1℃,在常规淋洗液NaHCO_3-Na_2CO_3中加入对-硝基苯酚作为有机改进剂,测定了I ̄-、SCN ̄-、离子。它们有良好的线性关系,三种离子的浓度在5.0~30.0mg/L范围内其相关系数分别为:0.9994、r_(SCN) ̄(-0.9906),检测限分别为:I ̄-0.17mg/L、SCN ̄-0.10mg/L、L。  相似文献   

11.
液流电池具有安全性高、循环寿命长以及环境友好等优势,被认为是大规模储能技术的首选技术之一,能够解决太阳能、风能等可再生能源发电不连续、不稳定的瓶颈问题,推动可再生能源的大规模应用,助力碳达峰、碳中和目标的实现。其中无机水系液流电池具有能量效率高、循环性能稳定、技术成熟等优势,是目前工程应用最为广泛的液流电池。本文介绍了无机水系液流电池的技术现状及其示范应用情况,系统阐述了新型无机水系液流电池的原理、技术现状及其挑战,同时对无机水系液流电池未来的技术创新与突破进行了展望,为无机水系液流电池的发展指明了方向。  相似文献   

12.
Multiphase flow metering with operationally robust, low-cost real-time systems that provide accuracy across a broad range of produced volumes and fluid properties, is a requirement across a range of process industries, particularly those concerning petroleum. Especially the wide variety of multiphase flow profiles that can be encountered in the field provides challenges in terms of metering accuracy. Recently, low-field magnetic resonance (MR) measurement technology has been introduced as a feasible solution for the petroleum industry. In this work, we study two phase air-water horizontal flows using MR technology. We show that low-field MR technology applied to multiphase flow has the capability to measure the instantaneous liquid holdup and liquid flow velocity using a constant gradient low flip angle CPMG (LFA-CPMG) pulse sequence. LFA-CPMG allows representative sampling of the correlations between liquid holdup and liquid flow velocity, which allows multiphase flow profiles to be characterized. Flow measurements based on this method allow liquid flow rate determination with an accuracy that is independent of the multiphase flow profile observed in horizontal pipe flow for a wide dynamic range in terms of the average gas and liquid flow rates.  相似文献   

13.
The aspects of emulsion flow through porous media are crucial for many industrial processes, especially in the development of Enhanced Oil Recovery (EOR) techniques and also during oily wastewater purification. In this paper we investigated the hydrodynamics of gravitational flow of emulsions with inner phase of different concentrations. We also tried to determine the quantitative changes in the droplet diameter distribution and concentration of emulsion flowing out of the bed. On the basis of experimental data, it was possible to describe the influence of emulsion concentration on the hydrodynamics process and to characterize the changes of the structure of emulsion.  相似文献   

14.
Magnetic resonance imaging (MRI) is a non-invasive and non-optical measurement technique, which makes it a promising method for studying delicate and opaque samples, such as foam. Another key benefit of MRI is its sensitivity to different nuclei in a sample. The research presented in this article focuses on the use of MRI to measure density and velocity of foam as it passes through a pipe constriction. The foam was created by bubbling fluorinated gas through an aqueous solution. This allowed for the liquid and gas phases to be measured separately by probing the 1H and 19F behavior of the same foam. Density images and velocity maps of the gas and liquid phases of foam flowing through a pipe constriction are presented. In addition, results of computational fluid dynamics simulations of foam flow in the pipe constriction are compared with experimental results.  相似文献   

15.
The purpose of this study was to investigate the influence of ionic strength of the carrier liquid, cross flow rate, focus flow rate, and sample load on the retention behavior of liposomes in asymmetric flow field‐flow fractionation (AF4). Two differently prepared samples of large unilamellar vesicles (LUV) were used. Experiments were performed varying the factors systematically and evaluating their effect on both retention behavior of the liposomes and on particle size as obtained from online coupled multi‐angle light scattering (MALS) analysis. The results showed that the focus flow rate had the least influence on the elution of liposomes. Elution of LUV is mainly governed by the chosen cross flow condition and ionic strength of the carrier liquid as well as its sample load. Optimal fractionation and size analysis were achieved using a sample load of about 10 μg, a cross flow gradient from 1.0 to 0.1 mL/min over 35 min and a carrier solution of NaNO3 with a concentration of 10 mM.  相似文献   

16.
The concept of flow “fine” synthesis, that is, high yielding and selective organic synthesis by flow methods, is described. Some examples of flow “fine” synthesis of natural products and APIs are discussed. Flow methods have several advantages over batch methods in terms of environmental compatibility, efficiency, and safety. However, synthesis by flow methods is more difficult than synthesis by batch methods. Indeed, it has been considered that synthesis by flow methods can be applicable for the production of simple gasses but that it is difficult to apply to the synthesis of complex molecules such as natural products and APIs. Therefore, organic synthesis of such complex molecules has been conducted by batch methods. On the other hand, syntheses and reactions that attain high yields and high selectivities by flow methods are increasingly reported. Flow methods are leading candidates for the next generation of manufacturing methods that can mitigate environmental concerns toward sustainable society.  相似文献   

17.
微流控层流技术的研究   总被引:5,自引:0,他引:5  
冯颖  王敏 《化学进展》2006,18(7):966-973
基于微型通道自身的层流特点而发展起来的多相层流技术,从最初的液-液微萃取开始,由于其结构加工简单、操作方便和分析功能强大,已逐渐发展成为一种加工分析方法,为微流控分析的研究应用打开了一个崭新的局面。本文概述了层流的基本原理,总结了近10年来在这方面的研究,包括层流界面间的分子扩散、转移现象和化学反应,以及层流刻蚀加工技术及其在制备纳米材料和在生命医学方面的应用。具体介绍了应用层流技术进行微芯片的加工制作,微型反应器的制备,离子、分子的分离分析,聚合物薄膜的形成和应用,微通道内有机合成反应的控制,溶液的浓度梯度控制以及在免疫检测中的应用,对细胞、生物大分子的操作控制,以及对生物试剂的预处理分析等。  相似文献   

18.
It is proved that the simplified Navier--Stokes (SNS) equations presented by Gao Zhi,Davis and Golowachof--Kuzbmin--Popof (GKP) are respectively regular and singular neara separation point for a two--dimensional laminar flow over a flat plate. The order of thealgebraic singularity of Davis and GKP equation near the separation point is indicated.A comparison among the classical boundary layer (CBL) equations, Davis and GKP equations,Gao Zhi equations and the complete Navier--Stokes (NS) equations near the separationpoint is given.  相似文献   

19.
Several studies have used microwaves as a heat source for carrying out various types of reactions employing circulation reaction vessels. The microwave flow chemical synthesis methodology is most appropriate in the use of microwaves in chemical syntheses. It can attenuate the problem of microwave heating (non‐uniform heating and penetration depth) and maximize the benefits (rapid heating and first temperature adjustments). In this brief review, we examine and explain some of the relevant features of microwave heating with applicative examples of the usage of microwave flow chemistry equipment in carrying out organic syntheses, enzymatic reactions, and (not least) nanoparticle syntheses.  相似文献   

20.
Various substances have been tested in the laboratory for their suitability as flow enhancers in aqueous solutions. The following maximum drag reductions (%) were obtained with pipes of 14 mm diameter and a Reynolds number of 105: Na-carboxy methylcellulose (32), hydroxyethyl cellulose (42), cetyltrimethylammonium chloride/-naphthol (74; Re=104), polyethylene oxide (76), K-polyphosphate/Na-pyrophosphate (77), polyacrylamide (80). The tested, partially hydrolysed polyacrylamide which was produced by a special process was found to be not only extremely effective and highly resistant to shear degradation but also unaffected by the salt content, the temperature and the water spoilage. Experiments were therefore made with this material on an industrial scale, that is to say with pipes up to 750 mm in diameter and 3200m in length. Whilst in the laboratory (pipes up to 14 mm in diameter) drag reductions were measured according to the Virk asymptote, the results obtained with large pipe diameters were lower. At diameters ranging from 300 to 750 mm a maximum drag reduction of 65% (at a concentration of 30 ppm PAAM and a constant wall shear stress of 50 Pa) has been obtained independently of the diameter.Symbols c concentration - d diameter - FE (as index) flow enhancer - k roughness - l length - n degree of polymerization - p pressure drop - r radius - Re Reynolds number - T temperature - v velocity - w (as index) water - drag reduction - friction factor - kinematic viscosity - density - wall shear stress Dedicated to Prof. Dr. R. Bonart on the occasion of his 60th birthday  相似文献   

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