氢化物发生辅助雾化火焰原子吸收法测定水中铅

研究了一种提高火焰原子吸收测定铅灵敏度的新方法——氢化物发生辅助雾化的火焰原子吸收法；方法采用硼氢化钠与铅(Ⅳ)在原火焰原子吸收雾化器喷口处反应生成氢化物，以提高火焰原子吸收法的雾化效率；采用重铬酸钾一酒石酸预处理体系，重铬酸钾氧化样品中铅(Ⅱ)为铅(Ⅳ)，酒石酸稳定铅(Ⅳ)的亚稳态化合物；对各种实验参数和干扰情况也进行了研究；方法操作简单、快速，灵敏度比通常的火焰原子吸收法提高了6．8倍；检出限(K=3，n=11)为6．64μg/L，线性范围为0．021～3．2mg／L；测定水样的回收率达94％～99％。     

原子捕集-导数火焰原子吸收光谱法测定中草药中的微量锌

提出了原子捕集－导数火焰原子吸收光谱法，考察了捕集管位置，火焰状态、冷却水流量、捕集时间、导数测量系统灵敏度档等实验条件对灵敏度的影响。在测量系统20mV/min灵敏度档下，捕集5min，特征浓度为0．037ng/mL，较常规火焰原子吸收光谱法提高了1243倍。     

流动注射-导数火焰原子吸收光谱测定植物油中的镍、锰、铬和铅

提出了流动注射－导数火焰原子吸收光谱测定植物油中微量镍、锰、铬和铅的新方法，流动注射进样技术克服了常规火焰原子吸收法耗样量大和基体干扰严重的缺点，导数技术应用于火焰原子吸收可提高方法的灵敏度和信号的选择性，流动注射与导数技术相结合应用于火焰原子吸收成功地测定了常规火焰原子吸收法和流动注射－火焰原子吸收法难以测定的植物油中微量镍、锰、铬和铅。镍、锰、铬和铅的特征浓度（μg/mL)，分别为0.0054、0.0034、0.0067、0.025，相对标准偏差在0.3%-2.8%的范围内。     

原子捕集-火焰原子吸收光谱法测定水中PPb级的银

水冷石英管作原子捕集器用于火焰原子吸收分析早于1976年已有报导。这种原子捕集法可以提高某些元素的灵敏度。Lau等仅报导出这种方法测定银的灵敏度(0.0009ppm),但未给出任何有关实验情况。笔者设计制作了一种简易的不锈钢原子捕集装置。在最佳实验条件下,这种原子捕集-火焰原子吸收法的灵敏度较常规火焰原子吸收法高二个数量级(特征浓度为0.0004ppm),可以测定水中ppb级的银。     

火焰原子吸收光谱分析中的原子捕集方法

原子捕集方法是一种在火焰中浓缩待测原子以提高火焰原子吸收光谱分析灵敏度的新方法。它包括开槽管原子捕集和水冷管原子捕集两种方法,具有装置简单、灵敏度高等特点,已开始应用于环境、临床医学等方面的分析。本文就两种原子捕集方法的原理、影响灵敏度的因素、干扰及机理诸方面作一比较性综述,并介绍了已有的应用。     

氢化物原子吸收法测定镍基合金中痕量铅

原子吸收法测定铅的灵敏度较低,常常应用有机试剂萃取富集,氢化物测定铅的条件非常苛刻,存在着一定的干扰。本文用氮-氢火焰考察了酒石酸-重铬酸钾-亚铁氰化钾体系中氢化法测铅的条件及共存离子的干扰,在酒石酸-重铬酸钾、硝酸-过氧化氢及硝酸-过硫酸铵三个体系中,加入亚铁氰化钾,使灵敏度提高了12倍。为克服镍、铜、铁等共存元素对测定的影响,采用硫酸锶共沉淀法进行分离,成功地测定了高温合金中的铅。方法适于镍基合金中0.0001—0.002%铅的测定,检出限为0.014微克/毫升;测定0.0005%的铅,变异系数为12.6%。一、仪器与试剂WFX-1A型原子吸收分光光度计;本所自制AHG-1型半自动氢化物装置。     

镉的原子捕集原子吸收光谱分析

原子捕集是一种在火焰中浓缩待测原子的预富集技术,它能提供极高的原子浓度供原子吸收测量,因而显著提高火焰法的灵敏度。原子捕集技术首先由Stephens提出,West等人作了较多工作。本文系统研究了各种条件对镉的捕集和释放的影响;对共存元素的干扰和试样分析进行了探讨。     

APDC-MIBK萃取火焰原子吸收法测定水中铜、镉、铅

重金属及其化合物毒性较大,进入人体后会引起各种生理变化,尤其对神经和心血系统有严重的危害性。因此对水中重金属进行分析具有重要的意义。直接火焰原子吸收法测定重金属的灵敏度不高,一般大于0.1mg/L[1],直接测定水样中微量铅较困难;石墨炉原子吸收法测定铅的灵敏度比直接火     

提高火焰原子吸收灵敏度的途径

火焰原子吸收法具有选择性好、测定精度高、应用范围广、快速简单等优点,但灵敏度比石墨炉原子吸收法低。因此,提高火焰原子吸收法的灵敏度具有重要意义。本文通过应用某些简单技术、分离富集待测元素、应用增感效应,论述了提高火焰原子吸收灵敏度的途径。     

用170-70型塞曼无火焰原子吸收法测定矿山排放水中微量铅

微量铅的定量测定通常采用双硫腙光度法和火焰原子吸收法。近来,有人用碘化物-甲基异丁酮萃取后用石墨炉原子吸收法测定。但有机试剂有毒,易挥发,造成环境污染。我们对矿山排放水中微量铅,采用塞曼无火焰原子吸收法测定,得到满意的结果。本法的灵敏度为0.0015微克/毫升/1%吸收,测定浓度范围0～0.080微克/毫升。实验部分     

热喷雾进样火焰原子吸收光谱法测定河水中的铅

铅被广泛应用于蓄电池、建筑材料、电缆外套等工业生产中，是造成河水污染的主要原因。铅为生物体有害元素，当其被人体组织吸收后，分布予肝、肾、肺、脑中，损害骨髓造血系统和神经系统。在环境检测中铅是必须检测的元素之一。火焰原子吸收光谱法具有仪器简单、操作方便、抗干扰能力强、稳定性好等特点，但由于雾化效率低和灵敏度低，不能直接用于测定样品中的低含量铅。     

Derivative flame atomic absorption spectrometry and its application in trace analysis

Flame atomic absorption spectrometry (FAAS) is an accepted and widely used method for the determination of trace elements in a great variety of samples. But its sensitivity doesn’t meet the demands of trace and ultra-trace analysis for some samples. The derivative signal processing technique, with a very high capability for enhancing sensitivity, was developed for FAAS. The signal models of conventional FAAS are described. The equations of derivative signals are established for FAAS, flow injection atomic absorption spectrometry (FI-FAAS) and atom trapping flame atomic absorption spectrometry (AT-FAAS). The principle and performance of the derivative atomic absorption spectrometry are evaluated. The derivative technique based on determination of variation rate of signal intensity with time (dI/dt) is different from the derivative spectrophotometry (DS) based on determination of variation rate of signal intensity with wavelength (dI/dλ). Derivative flame atomic absorption spectrometry (DFAAS) has higher sensitivity, lower detection limits and better accuracy. It has been applied to the direct determination of trace elements without preconcentration. If the derivative technique was combined with several preconcentration techniques, the sensitivity would be enhanced further for ultra-trace analysis with good linearity. The applications of DFAAS are reviewed for trace element analysis in biological, pharmaceutical, environmental and food samples.     

Direct determination of cadmium at parts-per-billion level in waters by derivative atomic absorption spectrometry using atom trapping technique

A method has been described for the direct determinations of trace cadmium using derivative atom trapping flame atomic absorption spectrometry with an improved water-cooled stainless steel trapping equipment. The characteristic concentration (gave a derivative absorbance of 0.0044) and detection limit (3sigma) of cadmium were 0.028 and 0.02 ng ml(-1) when collecting for a 1 min, respectively, which were 992 and 145-fold better than those of the conventional flame atomic absorption spectrometry. The detection limit and sensitivity of the proposed method for a 2 min collection time were 1 and 2 orders of magnitude higher than those of conventional flame atomic absorption spectrometry. The present method was applied to the determinations of cadmium in water samples with a recovery range of 91 approximately 111% and a relative standard deviation of 4.7 approximately 5.6%.     

增感效应火焰原子吸收光谱法测定 铁矿石中的微量铬

提出了增感效应火焰原子吸收光谱测定铁矿石中微量铬的新方法。研究了表面活性剂十二烷基硫酸钠(SDS)对铬的增感效果。增感效应可使火焰原子吸收光谱的灵敏度提高 27倍。本法已用于测定铁矿石中的微量铬,检测限为 7.0μg/L ,回收率为 91.1%～115.9%,RSD为 4.0%。     

The determination of gallium by atomic absorption spectrometry

The use of a nitrous oxide-acetylene flame for the determination of gallium by atomic absorption spectrometry was compared with the use of air-acetylene flames. The nitrous oxide method provided higher sensitivity and was much less sensitive to acid and base composition and to diverse added salts. Significant matrix and background effects, which occurred when gallium was determined in ore solutions with the air-acetylene flame, were eliminated with the nitrous oxideacetylene flame.     

Determination of lead traces in water and liqueurs by derivative atom trapping flame atomic absorption spectrometry

 A new method for the direct determination of lead traces using derivative atom trapping flame atomic absorption spectrometry (DAT-FAAS) with an improved water-cooled stainless steel trapping equipment in an air-acetylene flame was investigated. The optimum conditions concerning the sensitivity were studied. For a 1 min collection, the characteristic concentration (given as derivative absorbance of 0.0044) and the detection limit (3s) were 1.4 ng/mL and 0.27 ng/mL, respectively. This is 361 and 74-fold better than those of the conventional flame atomic absorption spectrometry (FAAS) and comparable to those of graphite furnace atomic absorption spectrometry (GFAAS). The detection limit and sensitivity of DAT-FAAS for a 3 min collection time were 2 and 3 orders of magnitude higher than those of conventional FAAS. The present method was applied to the determination of lead in water and liqueur samples with a recovery range of 94–108% and a relative standard deviation of 3.5–5.6%. Received: 10 January 1996/Revised: 9 December 1996/Accepted: 20 December 1996     

Evolved-gas zeeman flame atomic absorption spectrometry for the determination of arsenic compounds

An evolved-gas separation/flame Zeeman atomic absorption spectrometric approach is demonstrated for the speciation and determination of arsenic in oyster tissue. No digestion is needed and separation of inorganic arsenic compounds having similar boiling points is achieved. A stoichiometric or air-rich acetylene/air flame for atomic absorption spectrometry is not generally suitable for arsenic determination because of severe ultraviolet absorption interference at 193.7 nm and low sensitivity; polarized flame Zeeman atomic absorption spectrophotometry with a fuel-rich flame is suitable for the detection of traces of arsenic. The evolved-gas separation/Zeeman atomic absorption approach is simple, based on commercially available instrumentation, and useful for the selective determination of major arsenic compounds. Data are given to demonstrate optimal conditions and to show application to oyster tissue.     

增感效应导数火焰原子吸收光谱测定金属铜和铜合金中的微量铬

提出了增感效应导数火焰原子吸收光谱测定金属铜和铜合金中微量铬的新方法。研究了表面活性剂十二烷基硫酸钠对铬的增感效果。导数技术与增感效应相结合的可使火焰原子吸收光谱的灵敏度提高６８倍。本法测定金属铜和铜合金中的微量铬取得了满意效果。     

Determination of lead in plants in controlling phytoremediation processes using slurry sampling electrothermal atomic absorption spectrometry

The comparative determination of lead in plant samples by two atomic spectrometric techniques is reported. At first, slurry sampling electrothermal atomisation atomic absorption spectrometry (ETAAS) was applied. The results obtained were compared with those found after a wet digestion procedure by flame atomic absorption spectrometry (FAAS) or ETAAS. The accuracy of the studied methods was checked using a certified reference material (CL???1 CRM, Cabbage Leaves). The recovery of lead was 90% for slurry sampling ETAAS, and 86.6% for liquid sampling ETAAS. The advantages of the slurry sampling ETAAS method are the simplicity of sample preparation and very good sensitivity.     

火焰原子吸收光谱法测定土壤中钼

利用火焰原子吸收光谱法直接测定土壤中钼，以曲拉通X-100和三乙醇胺作为表面活性剂，富燃性的空气-乙炔火焰提高测定灵敏度，消除共存离子干扰。试验表明，方法可使吸光度增加55％，是测定土壤中钼的一种理想方法。