电沉积-钨丝电热原子吸收光谱法测定水样中的铅

研制了一种便携式钨丝电热原子吸收光谱分析装置,其主要包括:钨丝电热原子化器、多道微型CCD光谱仪、仪器电源系统以及控制系统。并将电沉积分离富集技术与该钨丝电热原子吸收光谱分析仪器结合,完成环境水样中铅的现场分析。并对铅的电沉积条件作了研究,最佳电沉积电位为负650 mV(vs.SCE),方法检出限:0.20μg/L,线性范围:1~15μg/L,对4μg/L Pb标准溶液10次重复测试,RSD为4.4%。     

基于国产仪器研究钨丝原子吸收光谱

用标准的150 W幻灯灯泡的钨丝作原子化加热材料,设计制作了一种新颖的、结构简单的钨丝电热原子化器,同时还设计了该原子化器的电源电路和信号的数据采集电路.该原子化器能的最高原子化温度可达3100 K左右;编写了硬件的控制软件和信号处理的应用软件.用该原子化器将实验室一台火焰原子吸收光谱仪改装成钨丝原子吸收光谱仪,并以铜元素标准溶液和PerkinElmer公司多元素标准溶液对仪器性能作了研究.仪器对铜的检出限为0.0133 μg/mL,线性范围为0.10～4.0 μg/mL;对1.0 μg/mL的铜标准溶液测试的相对标准偏差为RSD=4.1%(测试次数n=10),每次分析所需样品量20 μL.     

固体进样-石墨炉原子吸收光谱法测定土壤中重金属

采用直接固体进样-石墨炉原子吸收分析技术,研究了基体改性剂、灰化温度和原子化温度对土壤中As,Cd,Zn,Sn,Hg,Pb,Cr,Cu和Mn 9种重金属含量分析的影响。当As,Cd,Zn,Sn和Hg等元素使用Pd(NO3)2+M g(NO3)2作为基体改进剂时有利于吸光度的增加,而NH4H2PO4作为基体改进剂有利于Pb,Cr,Cu和M n吸光度的增加。方法应用于国家标准物质,结果与推荐值相吻合,方法 RSD优于7.0%,各种重金属方法检出限均低于0.1223 ng。     

电沉积-钨丝电热原子吸收光谱法测定地质样品中痕量金

以市售幻灯投仪卤钨灯泡钨丝为原子化器的钨丝电热原子吸收光谱分析仪(TC-AAS),功率小、仪器成本低[1,2],如用微型CCD光谱仪作检测系统,可以实现原子吸收光谱仪的小型化,甚至可用于野外现场分析[3,4].     

钨丝电热蒸发-氩氢火焰原子荧光光谱分析法研究

以钨丝原子化器替换传统氢化物原子荧光分析仪石英炉原子化器及其氢化物发生气体进样系统,构建了一种新颖的集电热蒸发进样-氩氢火焰原子化为一体的原子荧光光谱分析系统;并用标准溶液研究了该系统的分析性能.在优化的仪器条件下,直接在钨丝表面进样,Pb、Ni和Au的检出限分别为:1.5、2.0和2.0μL.再结合电沉积预富集技术,...     

石墨炉原子吸收法测定香根草中痕量Pb、Cd、Cu

采用石墨炉原子吸收法直接测定了香根草中重金属的含量,通过一系列实验,确定了石墨炉法测定Pb、Cd、Cu的最佳灰化温度和原子化温度,考察了精密度和回收率。结果表明,该法操作简单快捷,样品用量少,灵敏度高,稳定性好。     

石墨炉原子吸收光谱法直接测定电子级二乙二醇甲醚中铅

采用石墨炉原子吸收光谱法,直接测定了电子级二乙二醇甲醚(DGME)中的Pb含量。对吸收谱线、基体改进剂、仪器分析条件如灰化温度、原子化温度等进行了研究。分析线选择283.3 nm,以25 g/L草酸加10 g/L NH4H2PO4溶液作复合基体改进剂,灰化温度800℃,原子化温度1400℃,线性方程为y=0.0066ρ(μg/L)+0.0715,相关系数R=0.9961。方法相对标准偏差3.7%,检出限为0.144 ng/m L。     

螯合树脂富集——原子吸收法测定水中Cu~(2+),Zn~(2+)、Pb~(2+)、Cd~(2+)、Fe~(2+)、Mn~(2+)、Ni~(2+)的研究

本文以定量分析水中微量Cu、Zn、Pb、Cd、Mn、Fe、Ni为目的,对401型树脂与原子吸收分光光度法并用的基本条件进行了研究。本方法适用于清洁地面水水质的分析,其定量条件为:氢型树脂2.5克(干重),pH5.5～6,水样交换流速及洗脱液流速分别为2.5～5.0ml/min、3ml/min,以25ml容量瓶定容,试液置于原子吸收分光光度计上测定。用于浑河源头水质背景调查中,水样加标回收率为Cu:101～105％、Pb:110～116％、Zn:98～114％、Cd:94～96％、Mn:95～101％、Fe:97～100％、Ni:96～7％范围内。方法的检测下限为Cu:0.5ng/ml、Pb:1.1ng/ml、Cd:0.1ng/ml、Zn:0.25nmg/ml、Mn:0.7ng/ml、Fe:0.7ng/ml、Ni:0.7ng/ml。     

正交试验法优选石墨炉测定大米中镉的实验条件

利用L16(45)正交试验设计,考察了石墨炉原子吸收法测定大米中镉的灰化温度、灰化时间、原子化温度、原子化时间.确定了最佳灰化温度为450℃、灰化时间为15s、原子化温度为1750℃、原子化时间为4s等仪器的最佳参数.     

分散液液微萃取-石墨炉原子吸收光谱法测定环境水样中的Cd,Pb,Cr

以四氯化碳为萃取溶剂、甲醇为分散剂、三聚硫氰酸三钠盐为螯合剂,建立了分散液液微萃取-石墨炉原子吸收光谱法对环境水样中Cd,Pb,Cr测定的新方法。分别考察了体系p H、萃取溶剂种类及体积、分散剂种类及体积、螯合剂浓度、萃取时间等对方法的影响。在最佳条件下,Cd,Pb,Cr的检出限分别为0.00040,0.021和0.017 ng/m L,富集因子分别为95,68和100,相对标准偏差(n=7)分别为3.7%,3.0%和2.7%。方法可用于环境水样中Cd,Pb,Cr的测定。     

Evaluation of tungsten coil electrothermal vaporization-Ar/H2 flame atomic fluorescence spectrometry for determination of eight traditional hydride-forming elements and cadmium without chemical vapor generation

A tungsten coil electrothermal vaporizer (W-coil ETV) was coupled to an Ar/H(2) flame atomic fluorescence spectrometer for the determination of eight traditional hydride-forming elements (i.e., As, Bi, Ge, Pb, Sb, Se, Sn, and Te) as well as cadmium without chemical vapor generation. A small sample volume, typically 20muL, was manually pipetted onto the W-coil and followed by a fixed electric heating program. During the vaporization step, analyte was vaporized off the coil surface and swept into the quartz tube atomizer of AFS for further atomization and excitation of atomic fluorescence by a flow of Ar/H(2) gas, which was ignited to produce the Ar/H(2) flame. The tungsten coil electrothermal vaporizer and Ar/H(2) flame formed a tandem atomizer to produce reliable atomic fluorescence signals. Under the optimal instrumental conditions, limits of detection (LODs) were found to be better than those by flame atomic absorption spectrometry (FAAS) or inductively coupled plasma optical emission spectrometry (ICP-OES) for all the nine elements investigated. The absolute LODs are better or equivalent to those by hydride generation atomic fluorescence spectrometry (HG-AFS). Possible scattering interferences were studied and preliminary application of the proposed method was also reported.     

直接进样电热蒸发-原子荧光光谱法快速测定蒸馏酒中镉

为了快速低成本测定蒸馏酒中痕量重金属镉,利用钨丝电热蒸发器作为直接进样装置,与原子荧光光谱仪原子化器直接连接,构建了用于蒸馏酒中镉测定的直接进样原子荧光光谱检测系统(W-coil ETV-AFS),并对工作气体的气氛和流速、灰化和蒸发电压、样品承载量等参数进行了优化,建立了蒸馏酒中镉的直接进样快速检测方法。在最优条件下,Cd的检出限(LOD)为0.06μg/L(进样量为50μL),在0.5~100μg/L线性范围内回归系数(R²)为0.997;在5μg/L水平下,9个典型蒸馏酒样品的加标回收率在86.0%~116%,相对标准偏差RSD≤8.0%(n=3)。可以直接导入样品,无需复杂的前处理过程,具有良好的灵敏度、准确度和精密度,非常适合蒸馏酒中痕量镉的快速测定。     

Application of Microflame Atomizer to Gas Chromatography-Atomic Absorption Spectrometry

One of the successful methods for the determination of organometallic compounds is the combination of Gas Chromatography-Atomic Absorption Spectrometry (GC-AAS). The atomizer of AAS was connected with the column of GC by a transfer tube. Three types of the atomizer were reported as flame burner,electrothermal quartz tube and graphite furnace. A large amount of gas or electric energy was required to produce a high temperature for the atomization of analytes, A microflame atomizer of GC-AAS was developed in this paper to circumvent above problems. The volume of the atomizer is one-fifth of the normal flame burner, and a hydrogen gas was used as the carrier gas (35ml/min) and the fuel gas for the atomization of analytes.     

氢化物发生-冷原子荧光光谱法测定铜精矿中汞

用氢化物发生-冷原子荧光光谱法测定铜精矿中汞的含量。考察了仪器的工作条件原子化温度、原子化器高度、灯电流、负高压、载气和屏蔽气流量对测定的影响。采用主量元素匹配法消除基体干扰,优化了反应体系的介质与酸度、还原剂的浓度等条件。荧光强度与汞的质量浓度在2.0μg.L-1以内呈线性关系,检出限(3s/k)为0.0108μg.L-1,相对标准偏差(n=11)小于2%。此法用于铜精矿样品中汞含量的测定,加标回收率为92.0%～111.7%。     

Study on the Atomization Process of Lithium in Electrothermal Atomic Absorption Spectrometry

A new method for determining the kinetic order and activation energy for atom formation in electrothermal atomic absorption spec-trometry is proposed. The assumption of first order kinetics for atom formation and the steady-state approximation which appeared in the previous models is avoided in the proposed method. The kinetic parameters for atom formation of Li have been obtained, and the effect of the amount of analysed sample, ashing temperature, atomization temperature, heating rate, gas flow and tube surface on the atomization of Li has also been investigated.     

Hollow fiber supported liquid membrane extraction for ultrasensitive determination of trace lead by portable tungsten coil electrothermal atomic absorption spectrometry

Hollow fiber supported liquid membrane extraction (HF-SLME) was used to separate and enrich trace lead from a large volume of 250 mL water sample to a final tiny volume of 30 μL of 1-octanol, 5 μL of which was inject into a tungsten coil electrothermal atomic absorption spectrometer (W-coil ET-AAS) for determination of lead. Some important parameters that influenced the extraction and determination were investigated in detail, such as the concentration of ammonium pyrrolidine dithiocarbamate (APDC), pH of sample solution, stirring rate, extraction time, pyrolysis current, atomization current, carrier gas flow rate, as well as interferences. Under the optimized conditions, a practical enrichment factor of 499 and a limit of detection (3σ) of 0.2 ng mL^{− 1} were obtained. The calibration curve was linear in the range of 0.5–10 ng mL^{− 1}. The relative standard deviation (RSD) was 5.6% for five measurements of a 4 ng mL^{− 1} lead standard solution. The accuracy of this method was examined by the analysis of certified reference water samples (GBW(E)080398 and GSBZ(E) 50009-88) for lead. Finally, the proposed method was applied to the determination of lead in local tap water, pond water and river water, with recoveries in the range of 96–109% for spiked samples.     

D. Purves,trace-element contamination of the environment : Elsevier,Amsterdam, 1977, xi + 260 pp., price Dfl. 85, U.S. $34.75

A study of the dissolution rate of magnetite electrodes required a reasonably precise method for the determination of iron in aqueous solutions containing 1 mol kg^-1 sodium perchlorate. Atomic absorption spectrometry with electrothermal atomization in the wavelength range 248–392 nm with ashing at 1600°C proved to be the most satisfactory method. Iron concentrations in the range 0.1–100 μg ml^-1 were determined with 1-μl samples. The addition of low flow rates of acetylene to the nitrogen purge gas improved the reproducibility and increased the carbon rod lifetime.     

Application of atmospheric pressure dielectric barrier discharge plasma for the determination of Se,Sb and Sn with atomic absorption spectrometry

The atomization of hydride-forming elements, Se, Sb and Sn, has been studied with an atmospheric pressure dielectric barrier discharge atomizer. The elements were first converted to hydride through the reaction with NaBH₄. Then the hydride were atomized in the atomizer and detected by atomic absorption spectrometry. The effects of operational parameters such as power, gas flow rate and concentrations of HCl and NaBH₄ were investigated. Compared with other hydride atomization methods, the proposed atomizer shows the following features: (1) small size, which is preferable for the miniaturization of the total analytical system; (2) low temperature, which would be helpful for further improvement in the compactness of the total analytical system; (3) low power consumption, which is also necessary for the development of analytical instrumentation for in situ detection of environmentally important elements. The analytical performance of the atomizer has also been investigated. The detection limits of Sb, Se and Sn obtained with the present method were 13.0, 0.6 and 10.6 μg l^− 1. This detector is a very promising technique for hydride detection.     

Electrothermal atomic absorption spectrometry of silicon vaporized from different surfaces

The dependence of silicon absorbance on inert gas flow rate, ashing temperature and the amount injected was studied for uncoated, pyrolytically coated and tantalum carbide-coated graphite tubes. The reasons for the anomalous curvature of the calibration graphs and other unusual phenomena are discussed. Most sensitive results for silicon were obtained by isothermal atomization from a tantalum-treated tube and platform.