Sensitivity Enhancement for Slotted Quartz Tube Flame Atomic Absorption Spectrometry Using a Gas Screen

Slotted Quartz Tube (SQT) is a simple device that provides a sensitivity enhancement of 2–5 times in Flame Atomic Absorption Spectrometry (FAAS) depending on the element. A Gas Screen-Slotted Quartz Tube (GS-SQT) was designed to further increase sensitivity. For this purpose, two slotted gas chambers were fixed on the left and right sides of a burner head and Ar gas was supplied into these chambers perpendicular to the light path to produce two thin layers of gas screen. It was observed that these Ar screens can move up the flame tails in two ends of SQT. In addition to an increase in sensitivity by the use of SQT, Ar screen resulted in a further improvement in characteristic concentrations, C₀, by a factor of 1.60 for Cd, 2.01 for Co, 1.42 for Cu, 1.94 for Mn, 1.86 for Ni, 1.78 for Pb, 1.62 for Se, and 1.09 for Zn. In addition to the enhancement in sensitivity, gas screen also helps by protecting the spectrometer from the adverse effect of using slotted quartz tube. The system is very simple and low-cost; it can be produced and applied easily.     

Determination of Bismuth in Bottled and Mineral Water Samples at Trace Levels by T-Shaped Slotted Quartz tube-Atom Trap-Flame Atomic Absorption Spectrometry

An accurate and reliable analytical method for the determination of bismuth at trace levels in bottled and mineral water samples has been developed based on hydrogen assisted T-shape slotted quartz tube-atom trap-flame atomic absorption spectrometry (T-SQT-AT-FAAS). Conventional FAAS is not sufficiently sensitive to measure trace and ultra-trace levels of metals due to the low nebulization efficiency and short residence time of atoms in the light path. To overcome this problem, atom trapping with a T-shaped slotted quartz tube was coupled to the FAAS system. Bismuth atoms were trapped on the surface of T-SQT and released by hydrogen gas, which provided a reducing environment. All of the system parameters such as flame type, hydrogen flow rate, the height of T-SQT from the burner head, and trapping period were optimized to enhance the analytical signal to attain low detection limits. After obtaining the optimum conditions, the limit of detection and limit of quantitation of the developed method were found to be 0.95 and 3.2?µg L^?1, respectively. Recovery values were obtained between 90% and 104% that showed good accuracy and applicability of the proposed method to the analysis of bottled and mineral water samples.     

石英缝管火焰原子吸收法测定食醋中的痕量铅

采用石英缝管装置,辅助火焰原子吸收光谱法测定了食醋中的痕量铅。对铅的测量灵敏度较常规火焰原子吸收法提高了4倍以上。装置简单,方法简便,有效地降低了对测量灵敏度较低的组分的富集要求,提高了分析结果的可靠性。     

流动注射石英管原子吸收法测定微量总汞

建立了一套流动注射石英管原子吸收光谱法测定土壤、植物和药品等样品中微量Hg的方法，研究了酸度、载液和还原液流速及其浓度、氩气流量等条件对测定结果的影响。采用五氧化二钒、硝酸、硫酸进行消解，可获得可靠的分析结果。方法特征量为59pg，检出限为0.028μg/L；相对标准偏差为1.60%-3.86%；回收率为94％－102％。     

浊点萃取-石英双缝管捕集火焰原子吸收光谱法分析铬价态

在不同pH值的缓冲溶液中,亚硝基苯胲铵盐(铜铁试剂)可与Cr(Ⅵ)及Cr(Ⅲ)络合生成中性疏水络合物,以Triton X-114为萃取剂,浊点萃取分离富集Cr(Ⅵ)及总铬,石英双缝管原子捕集-火焰原子吸收光谱法(STAT-FAAS)测定铬价态.实验对浊点萃取时溶液的pH值、铜铁试剂和Triton X-114的用量、离心分离时间、平衡温度和时间等影响因素进行了研究.结果表明,分别在pH=3.0和6.0的溶液中,40 ℃恒温加热15 min后,离心5 min,Triton X-114浊点萃取Cr(Ⅵ)及总铬的富集倍数达到50倍(100 mL起初样品溶液/2 mL最终测定液).和普通火焰原子吸收光谱法(FAAS)相比,利用石英双缝管原子捕集技术,STAT-FAAS法测定铬的灵敏度提高了近5倍.本方法测定Cr(Ⅵ)及总铬的线性范围分别为0.005～0.5 mg/L和0.01～1.2 mg/L;检出限分别为0.66 μg/L和0.81μg/L.     

缝管原子捕集方法研究

试验了各种条件对Ｂｉ、Ｇａ、Ｓｂ灵敏度影响。结果表明，分别用不同的火焰条件进行原子捕杀与放可获得最佳灵敏度。捕集１ｍｉｎ，测得Ｂｉ、Ｇａ、Ｓｂ的特征浓度依次为３．５×１０－３、１．６×１０－３、１．８×１０－３μｇ·ｍｌ－１，它比常规火焰原子吸收光谱法的灵敏度分别提高２５４、１３１、２３９倍。Ｂｉ、Ｇａ、Ｓｂ的变异系数各为２．９、３．５、４．７％。本法测定了纯锡中微量Ｂｉ、Ｓｂ。     

缝式石英管捕集技术的改进

试验了各种条件对Ag、Au、Cu、Pb和Zn灵敏度影响.结果表明,分别用不同火焰条件进行原子捕集与释放可获得最佳灵敏度。捕集1min,测得Ag、Au、Cu、Pb和Zn的特征浓度分别为8.1×10、1.7×10~(-3)、1.8×10~(-3)、2.4×10~(-3)和1.3×10~(-4)μg/ml,比常规火焰原子吸收光谱法的灵敏度分别提高62、106、28、83和77倍。Ag、Au、Cu、Pb和Zn的相对标准偏差依次为2.8％、3.1％、2.6％、2.7％、5.4％。本法测定了牡蛎中Ag和Cu。     

缝管原子捕集初探

本文针对九种元素初步探索了缝管捕集原子吸收的各种参数影响,给出缝管捕集法与常规火焰法的灵敏度、精密度对比结果。并进行了单缝管、双缝管及微量进样的比较实验。该法用于测定自来水和啤酒样品中的Cd、Cu、Pb、Zn,取得结果较为满意。     

微乳相萃取分离富集-原子吸收光谱法分析铬形态

建立了一种微乳相萃取分离-石英双缝管原子捕集火焰原子吸收光谱法(STAT-FAAS)分析环境水样中铬形态的新方法。该方法中,Cr(Ⅲ)与8-羟基喹啉反应形成的疏水性配合物,经萃取进入微乳相,Cr(Ⅵ)留在水溶液中,从而实现Cr(Ⅲ)与Cr(Ⅵ)的相互分离。Cr(Ⅵ)含量的测定通过过氧化氢溶液将Cr(Ⅵ)还原为Cr(Ⅲ),按同样方法分析。实验对微乳相萃取的主要影响因素进行了优化。结果表明,经优化后实验条件为:平衡温度80℃,平衡时间10min,溶液酸度pH=9.0,NH3-NH4Cl缓冲溶液用量2.0mL,8-HQ用量0.05mmol;TritonX-100微乳液组成:m(TritonX-100):m(正戊醇):m(正己烷):m(水)=3.0:15:1.5:4.0。在此条件下,萃取的富集倍数达到25倍(50mL起初样品溶液/2mL最终测定液),线性范围为2.5～500μg/L,检出限为0.62μg/L,相对标准偏差(RSD)为3.8%(n=10,c=10μg/L)。本方法已成功地应用于电镀废水中铬形态分析。     

原子吸收光谱和原子发射光谱法测定工业废水中的总铬

为了探讨原子吸收光谱法和原子发射光谱法测定工业废水中的总铬分析方法的异同,分别采用两种方法对工业废水中的总铬进行了对比分析,对样品前处理方法,方法的标准曲线、检出限、准确度、精密度、干扰及消除等进行了比较,并对两种方法的测定结果进行t检验。结果表明,两种方法具有良好的一致性。相对来说,原子发射光谱法各方面指标要优于原子吸收光谱法。     

甘薯中微量钙铁的原子吸收分光光度法测定

研究了用原子吸收分光光度法测定甘薯中的微量钙、铁的含量；采用高温灰化法对样品进行处理，并对40多种不同品种和不同种植地区的甘薯进行了实样测定和含量差异比较；对9个样品进行钙和铁的加标回收试验，测定的回收率在91％－107％之间，相对标准偏差RSD（n=9)分别为4．6％、5．4％，结果令人满意。     

原子吸收,原子荧光和火焰光谱分析

本文根据1988～1990年国内主要分析刊物所发表的文章,以及第三届北京分析测试学术报告会及展览会(BCEIA)、中国化学会第三届原子光谱会的主要论文,对我国原子吸收、原子荧光和火焰光谱分析的进展进行了评述,对于国外有关的重要文章也简单地加以介绍。     

Electrothermal Atomization Atomic Absorption Spectrometry with Platinum Tube Atomizer in Air

Abstract

An electrothermal atomization method of atomic absorption spectrometry using a platinum tube atomizer in air is described. The atomizer consists of 0.025 mm-walled platinum tube and two supports. The remarkable merit of the platinum atomizer is the stability in air, when heated. This paper describes the improved performance for volatile elements like alkalimetals. Detection limits and characteristic mass are calculated for 7 elements and compared with literature values. The platinum atomizer can be used with a simple, effective and relatively low-cost atomic absorption spectrometer for routine in situ analysis.     

缝管原子捕集法中的原子化机理

本文用Ｘ射线衍射分析法研究了１１个元素在开缝石英管中原子捕集与释放机理。Ａｇ和Ｂｉ以金属形式被捕集，而Ｃｄ、Ｃｕ、Ｉｎ、Ｎｉ、Ｓｂ、Ｚｎ、Ｐｂ、Ｃｏ、Ｇａ则以氧化物或硅酸盐形式捕集。这些元素在放时直接从熔融物蒸发原子化。５％乙醇或丙酮能提高大多数元素的灵敏度。大多数元素在Ａｌ２３涂层管上的灵敏度较高，在Ｌａ２Ｏ３涂层管上的检出限较低，精密度较高。     

原子吸收原子荧光和火焰光谱分析

原子吸收原子荧光和火焰光谱分析何华＊１９５８年中山大学物理系毕业，现任中国广州分析测试中心研究员。中国仪器仪表学会分析仪器学会理事。《分析测试学报》、《光谱学与光谱分析》、《分析仪器》以及《分析测试仪器通讯》等期刊编委。多年来主要从事原子光谱分析新...     

原子吸收、原子荧光和火焰光谱分析

本文主要根据1991～1993年第一季度国内重要分析刊物所发表的文章以及在此期间重要全国性会议的主要论文,对我国原子吸收光谱法,原子荧光光谱法以及火焰发射光谱分析法的进展作一综述。文中共收集文献692篇。     

Preconcentration,Determination and Speciation of Chromium(III) Using Solid Phase Extraction and Flame Atomic Absorption Spectrometry

A facile, reliable and reproducible method for speciation and determination of the traces amounts of chromium(III) in waste water has been developed. The method was based on complex formation on the surface of the ENVI‐18 DSK^? disks followed by stripping of the retained species by minimum amounts of appropriate organic solvents. The elution was efficient and quantitative. The effects of potential interfering ions, pH, ligand amount, stripping solvent, and sample flow rate were also investigated. Under the optimal experimental conditions, the break‐through volume was found to be about 1500 mL providing a preconcentration factor of 300. The maximum capacity of the disks was found to be 225 ± 3.9 μg for Cr³⁺. A limit of detection of 0.02 ng.mL ^?1 was obtained, and the method was applied for determination of chromium in electroplating industries waste water located in the eastern regions of Tehran.     

浊点萃取-电热原子吸收光谱法分析铬的形态

提出了测定铬形态的新方法——浊点萃取-电热原子吸收光谱法(PPE-ETAAS)。该法基于利用非离子表面活性剂Triton X-100的浊点现象，当加热至其浊点时，溶液分为两相，Cr(Ⅲ）与8-羟基喹啉形成的疏水性螯合物进入富胶束相中，从而实现与Cr(Ⅵ）的分离。在本法中，8-羟基喹啉既作为化学分离，富集剂，又作为ETAAS测定中的化学改进剂。对影响浊点萃取分离的主要因素进行了详细的研究。在最优实验条件下，方法测定Cr(Ⅲ）的检出限为0．023μg/L；相对标准偏差为1．1％(C=2．0μg/L，n=6)。本法具有简便、灵敏、富集倍数高和避免使用有机溶剂的优点。     

火焰原子吸收光谱法测定空气中铬含量的不确定度评定

用火焰原子吸收光谱法测定空气中铬含量,评定了测定过程的不确定度,把不确定度分解为标准溶液及配制引入的不确定度、标准曲线拟合引入的不确定度和样品重复测定引入的不确定度等七个因素,系统分析并计算各不确定度分量和扩展不确定度.结果表明,其中采集样品引入的不确定度是主要影响因素,空气中铬含量为3.88 μg/m3时,扩展不确定度为0.12 μg/m3.