石墨炉原子吸收光谱法测定茶叶中的铅

采用石墨炉原子吸收光谱法测定茶叶中铅,以NH4H2PO4作为基体改进剂,提高了测定的灰化温度,消除了基体干扰.方法简便,快速,准确度高.通过对标准物质的多次测定,结果均在其保证值范围内,相对标准偏差为2.8%.对样品进行加标回收试验,回收率为96%～105%,方法检出限为0.12μg/L.     

Determination of traces of silver in copper by direct Zeeman graphite furnace atomic absorption spectrometry

Summary A method was developed to determine traces of silver in copper by direct Zeeman graphite furnace atomic absorption spectrometry (ZAAS) on solid samples. The system is calibrated using quantitatively doped copper, whose blank silver content is determined using an iterative process. The method has been applied to the analysis of several candidate reference materials. Relative standard deviations of 2 to 5% are obtained in the range 1 to 12 g·g^–1. Furthermore, it was also applied to assess the homogeneity of a neutron dosimetry candidate reference material.     

Determination of lead in geological and biological materials by graphite furnace atomic absorption spectrometry

Summary Serious systematic errors inherent in the determination of lead in geological and biological samples by flameless atomic-absorption spectrometry are demonstrated. The reduced absorption of lead is due to partial interaction with alkaline, alkaline-earth and iron chlorides during the atomization stage. Incomplete dissociation of the volatile monochloride of lead in the gaseous phase reduces the absorption signal. An addition of 20% hydrogen to nitrogen (purge gas) diminishes signal suppression by removing the chlorine in form of volatile HCl. The detection limit is about 0.6 ppm in rocks and about 0.3 ppm in plant materials. Depending on the content in the samples the relative standard deviation is between 1 and 12%. The accuracy of the method was tested on 39 international standard reference samples.

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Bestimmung von Blei in geologischen und biologischen Materialien durch AAS mit der Graphitrohrküvette

Zusammenfassung Schwerwiegende systematische Fehler bei der Bestimmung von Blei in geologischen und biologischen Materialien mit der Graphitrohrküvette werden aufgezeigt. Die Reaktion von Blei mit Alkali-, Erdalkali- und Eisenchloriden während der Atomisierungsphase führt zur Bildung von Bleimonochlorid, das nur unvollständig dissoziiert und eine Signalunterdrückung zur Folge hat. Ein Zusatz von 20% Wasserstoff zu Stickstoff als Spülgas vermindert die Signalunterdrückung, indem überschüssiges Chlor als Chlorwasserstoff entfernt wird. Die Nachweisgrenze liegt bei ca. 0,6 ppm für Gesteine und bei ca. 0,3 ppm für Pflanzenmaterialien. Je nach der Konzentration beträgt die relative Standardabweichung 1–12%. Die Genauigkeit der Methode wurde an 39 internationalen Standardreferenzproben überprüft.

     

Determination of tin and lead in sediment slurries by graphite furnace atomic absorption spectrometry

Methods were determined for lead and tin determinations in river, marine and lake sediments by slurry sampling and graphite furnace atomic absorption spectrometry. The optimizations were carried out using River Sediment BCR 320 and Marine Sediment PACS-2 for Pb and Sn, respectively. For Pb determination, the parameters studied included inorganic acid mixture, stabilizing agent, sample mass and sonication time. The influence of diluents and the extraction to the liquid phase for two different matrices was evaluated for Sn. The Pb content in the slurry liquid phase was ca. 56%, and ranged from 75% to 100% for Sn. Representative masses of 34 and 45 mg, and effective masses of 12 and 48 μg for Pb and Sn, respectively, were obtained under optimized conditions. Detection and quantification limits of 0.2 and 0.7 μg g⁻¹ for Pb, and 1.5–2.6 and 4.5–7.6 μg g⁻¹ for Sn were obtained.

     

石墨炉原子吸收光谱法测定中药漏芦中微量铅

中药漏芦具有抑制动脉粥样硬化、抗脂质过氧化、减弱血小板聚集和提高免疫力等作用[1]。测定中药中微量元素的含量,对于探讨中药药理、提高药效和降低毒副作用有重要的意义[2,3]。铅是一种毒性元素,它在人体中具有累积性,通过肠胃道吸收,严重损害神经系统、造血系统和消化系统,从而导致肌体免疫力降低。本文选用磷酸氢二铵为基体改进剂,采用石墨炉原子吸收光谱法,对漏芦中Pb的含量进行了测定,考察了影响测定结果的主要因素。样品分析结果表明,本法简便、快速、灵敏、准确。1　实验部分1 1　仪器及工作条件180 80型原子吸收分光光度计、…     

Determination of traces of molybdenum in sea water by combined anion-exchange — graphite furnace atomic absorption spectrometry

Summary Traces of molybdenum in sea water have been preconcentrated by anion-exchange from acidified samples in the presence of sodium azide. Molybdenum adsorbs strongly on a column of Bio-Rad AG 1 (Cl^–) and can be stripped easily by elution with 2 mol/l NH₄Cl — 2 mol/l NH₄OH solution. Molybdenum in the effluent is determined by graphite furnace atomic absorption spectrometry. The combined method allows to determine traces of molybdenum in sea water as well as non-saline water on a 100 ml sample basis. The method gives a relative standard deviation of better than 8% at a molybdenum level of 10 g 1^–1 of sea water.

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Bestimmung von Molybdänspuren in Meereswasser mit Hilfe einer Kombination von Anionenaustausch und elektrothermischer Atomabsorptionsspektrometrie

     

Determination of organotin compounds in marine sediments using graphite furnace atomic absorption spectrometry

Organotin compounds, especially tributyltin, began to cause concern 10 years ago due to a high toxicity towards marine organisms. Several methods of analysing organotin compounds in various matrices have already been developed to determine organotin species simultaneously, but these are quite expensive as special equipment and specialized staff are needed. A simple screening method, which determines the organic tin compounds in the sediment, has therefore been developed and validated. The method can easily be implemented in laboratories accustomed to tracelement analyses; the sediment is extracted by a two-phase extraction and the organic extract is analysed using graphite furnace atomic absorption spectrometry (GF AA.) The screening method has been validated using high-pressure liquid chromatography-inductively coupled plasma mass spectrometry (HPLC–ICP MS).     

石墨炉原子吸收测定模拟体液中的镍

人工关节置换手术的出现是外科手术治疗软骨病损的一次巨大的进步。但人工关节假体的后期松动是长期困扰其发展的难题。镍钛合金人工关节假体材料在体液中的腐蚀与磨损,以及磨损颗粒引起周围组织的异物反应,是造成晚期关节假体松动的主要原因。另一方面,镍钛合金植人体在体液腐蚀下释放的镍离子对人体有害,而且还可能致癌。因此,对镍钛合金进行表面改性,以提高其耐磨与耐腐蚀性能很有必要。     

石墨炉原子吸收光谱法测定中药口服液中的铬铅镉

利用石墨炉原子吸收光谱法测定,采用常温消解和密闭微波消解等方式处理口服液样品,并进行比较。结果表明,采用HNO3 HClO4 H2O2作为消解试剂用常温消解方式进行消解后,可不加基体改进剂直接进行测定,在此基础上研究了石墨炉原子吸收测定的最佳条件。应用这种方法测定了双黄连、清开灵、生脉饮和抗病毒口服液中痕量镉、铬和铅,RSD小于5．0％,回收率在83．4％～113％。     

Determination of lead in water samples by graphite furnace atomic absorption spectrometry after cloud point extraction

Cloud point extraction (CPE) has been used for the pre-concentration of lead, after the formation of a complex with 2-(5-bromo-2-pyridylazo)-5-(diethylamino)-phenol (5-Br-PADAP), and later analysis by graphite furnace atomic absorption spectrometry (GFAAS) using octylphenoxypolyethoxyethanol (TritonX-114) as surfactant. The chemical variables affecting the separation phase were optimized. Separation of the two phases was accomplished by centrifugation for 15 min at 4000 rpm. Under the optimum conditions i.e., pH 8.0, cloud point temperature 40 °C, [5-Br-PADAP] = 2.5 × 10⁻⁵ mol l⁻¹, [Triton X-114] = 0.05%, added methanol volume = 0.15 ml, pre-concentration of only 10 ml sample permitted an enhancement factor of 50-fold. The lower limit of detection (LOD) obtained under the optimal conditions was 0.08 μg l⁻¹. The precision for 10 replicate determinations at 5 μg l⁻¹ Pb was 2.8% relative standard deviation (R.S.D.). The calibration graph using the pre-concentration system for lead was linear with a correlation coefficient of 0.9984 at levels near the detection limits up to at least 30 μg l⁻¹. The method was successfully applied to the determination of lead in water samples.     

石墨炉原子吸收光谱法测定食盐中钡

建立了石墨炉原子吸收光谱法测定食盐中钡的方法,不需要对石墨管做任何处理,也无需对样品进行除盐处理,通过优化石墨炉升温程序,极大改善了食盐样品中钡测定的灵敏度和峰型。钡在0.00~50.0 μg/L浓度范围呈现良好的线性关系,相关系数优于0.999,检出限为0.650 mg/kg(以称样量0.200 g,定容至50 mL计算)。食盐样品钡加标回收率范围为81.3%~105.1%,相对标准偏差在8.9%以内。方法稳定可靠,准确度较高,适用于食盐中钡的测定。     

石墨炉原子吸收法测定石脑油中微量砷

试样用四氢呋喃（THF）有机溶剂稀释,以硝酸镍为基体改进剂,研究采用石墨炉原子吸收法直接进样测定石脑油中的砷量。研究表明,砷量在0～50μg／L范围内线性关系良好,回收率93％～104％。     

Determination of cadmium in orthophosphoric acid by graphite furnace atomic absorption spectrometry

Summary Cadmium has been determined in analytical-reagent grade orthophosphoric acids by direct graphite furnace atomic absorption spectrometry with Zeeman background correction. The detection limit was 3.0 pg cadmium, corresponding to 1.0 g/l of cadmium in the concentrated acid. Most of the acids analyzed contained 2–5 g/l of cadmium. The method was checked using electrochemical preconcentration of cadmium, followed by flame atomic absorption spectrometry.     

石墨炉原子吸收法测定3-苯基丙烯酸酯类化合物中微量钯

利用高灵敏的石墨炉原子吸收法,在V(HCl):V(HNO3):V(H2O)＝5:1:94混合酸介质中测定苯基丙烯酸酯类化合物中的钯量.已纯化样品钯量的平均值是6.76 μg/g,标准相对偏差是4.8%,平均回收率为99.3%;未纯化样品钯量的平均值是121.2 μg/g,平均相对偏差是5.4%.还讨论酸介质对测定钯吸光度的影响,通过比较找到了合适的酸介质组成.     

Determination of cadmium and lead in plastic material from waste electronic equipment using solid sampling graphite furnace atomic absorption spectrometry

The European initiatives to minimize waste electric and electronic equipment (WEEE) and the restriction of hazardous substances (RoHS) had a major impact on the routine control of hazardous substances, including toxic trace metals, such as cadmium and lead, in all kinds of materials that are used in electric and electronic equipment. Instead of analyzing a whole computer, cell phone or television set, individual parts are normally investigated in order to simplify the analytical task. Plastic components are important constituents of electronic equipment, and a potential source of toxic trace metals that are added as catalysts, stabilizers or colorants. As high-tech plastic materials are designed to be resistant against chemical attack, they are usually difficult to bring into solution. A procedure is proposed in the present work that uses direct solid sampling graphite furnace atomic absorption spectrometry and calibration against aqueous standards. The method is sensitive, fast, and it does not require any sample preparation. The limits of detection of 0.1 mg kg^− 1 for Cd and 0.6 mg kg^− 1 for Pb are more than adequate for the purpose. Additional means are presented for reducing the sensitivity in order to cope with high analyte concentration. The method has been tested analyzing two certified reference materials, and good agreement with certified values has been obtained.     

Preconcentration of lead in biological matrices for graphite furnace atomic absorption spectrometry

Lead was transferred by a two-step extraction procedure from complicated biological matrices into an aqueous solution. Thereafter, lead could be accurately determined in the aqueous solution without interference by graphite furnace atomic absorption spectrometry (GFAAS). Biological samples were digested sequentially by a mixture of sulphuric acid and nitric acids and a strong oxidant, potassium peroxodisulphate. Lead was extracted by dithiocarbamate in chloroform from the digest solution and subsequently back-extracted into a mercury(II) solution. Matrix materials such as chloride, phosphate and sulphate, which were known to cause serious interference in the determination of lead by GFAAS, could be eliminated in the preconcentration procedure. Close to 90% recovery of lead was achieved. The proposed procedure was applied for the analysis of several NBS biological standard reference materials containing lead in the mg kg^?1 range and satisfactory results were obtained.     

石墨炉原子吸收法快速测定血液中铅和镉

建立了快速测定血液中铅和镉的石墨炉原子吸收光谱法。使用5%硝酸溶液对样品进行脱蛋白处理,然后在旋涡混合器上振摇,离心后取上清液上石墨炉原子吸收进行测定。 结果表明,Pb、Cd工作曲线线性关系良好,相关系数均大于0.9994;方法检出限分别为4.32μg/L和0.27μg/L;Pb的回收率为91.60%～97.31%,镉的回收率为97.04%～98.86%;Pb测定的RSD（n=7）为2.35%,Cd测定的RSD（n=7）为1.53%。冻干牛血铅、镉标准物质GBW09139k和GBW09140k的测定值与参考值吻合。该方法快速准确,精密度、准确度、检出限等测定结果令人满意。可以作为日常血铅、血镉的检测的方法。     

石墨炉原子吸收法测定钢中铅的干扰抑制

研究了石墨炉原子化法测定钢铁中痕量铅的干扰情况，并进行了干扰抑制实验。提出了抑制干扰的方法。     

微波消解-石墨炉原子吸收光谱法测定纸质包装材料中铅含量

建立了微波消解-石墨炉原子吸收光谱法测定纸质包装材料中铅含量的方法.该方法具有良好线性关系,线性相关系数R~2为0.999 5,检出限为0.028μg/L,回收率为97%~102%,其相对标准偏差在3.14%~5.76%之间,优点为检出限低、精密度好、准确度高,能精确测定纸质包装材料中的铅含量.