Simple Method for Simultaneous Determination of Selenium and Arsenic in Human Hair by Means of Atomic Fluorescence Spectrometry with Hydride Generation Technique

This study describes a simple, rapid and reliable method for simultaneous determination of selenium and arsenic in human hair by means of atomic fluorescence spectrometry combined with a hydride generation technique (HG-AFS). The procedure developed encompasses microwave digestion of a sample in the nitric acid environment only. The interferences caused by nitrous oxides are eliminated by removing a gas from above the digested solution with a stream of argon. The sample is then chemically treated in a flow-through hydride generation system and exposed to measurements in a double-channel atomic fluorescence spectrometer. The method permits determining both analytes in the linear range of 0.5–100µgL^–1 with a detection limit equal to 0.2µgL^–1, as well as with very good repeatability not exceeding 1% for Se and 2% for As. No mutual interferences from either of the analytes in the concentrations ranges matching the hair composition were found. The method was verified in terms of accuracy with the use of a reference material and then applied to the analysis of the natural samples of human hair.     

人发中硒的流动注射-氢化物发生原子吸收光谱法测定

在选择了头发最佳消化方法、硒氢化物生成及检测最佳条件的基础上 ,将流动注射 (FI)、氢化物发生(HG)技术与蒸汽发生原子吸收光谱法 (VGA -AAS)有机地结合起来 ,建立了人发中硒含量的测定方法 ;该法简便、快速、灵敏度高 ,测定的相对标准偏差 (n=6)为1.8 %～3.1 %,试样加标回收率为97 %～102 % ,硒的检出限为0.25μg·L-1,用于实际人发样品中硒的测定 ,结果令人满意     

流通式电化学氢化物发生法原子吸收测定硒的研究

采用自行研制的以铅作阴极、石墨作阳极无隔膜分隔的流通式电化学氢化物发生器,电解产生的气体经气液分离器后直接送入火焰原子吸收进行测定,因无外加载气减少了稀释提高了灵敏度。研究了各种影响因素,选择了最佳条件,以0．5mol／L硫酸作电解液,以1．3mL／min流速通过氢化物发生器,电解电流为2．0A。结果表明硒质量浓度在0～5μg／mL范围内呈良好的线性关系,其相关系数为0．9988,相对标准偏差为4．4％,特征质量浓度为0．0397μg／mL,检出限为0．084μg／mL。     

氢化物发生原子荧光法测定头发样品中的硒

利用氢化物发生原子荧光法测定头发样品中微量硒元素。将头发样品用高氯酸–硝酸混酸(体积比为1∶3)消化,样品中各种形态的硒元素均被转化为Se(Ⅳ)和Se(Ⅵ)。在6 mol/L盐酸中,Se(Ⅵ)被还原为Se(Ⅳ)后导入氢化物发生原子荧光仪进行测定,硒的质量浓度在0~20 ng/m L与荧光强度呈良好的线性关系,相关系数r=0.999 9,检出限为0.021 8 ng/m L,加标回收率为95%~108%,测定结果的相对标准偏差为0.8%(n=5)。该法简便、快速、准确,适于头发中微量硒元素的测定。     

连续流动氢化物发生—原子吸收光谱法测定地质样品中痕量硒

经试验研究，选定了分析地质样品中痕量硒的测定体系，建立了切实可行的分析方法，该方法不需分离，直接测定，灵敏度高，干扰少，方法测定下限可达０．０２μｇ／ｇ，进行了部分样样分析，结果令人满意。     

植物和人发样品中痕量铅的氢化物原子荧光测定

以双电极高强度空心阴极灯作激发光源，于铁氰化钾碱性体系内进行铅的氢化反应。实验表明，原子化过程中石英炉芯对铅烷存在吸附。在最佳测试条件下，溶液检出限为０．１７μｇ／Ｌ，分析了国家一级植物标样和头发标样中痕量铅，取得令人满意的结果。     

流动注射氢化物发生-原子吸收光谱法 测定镍基合金中的硒和锡

建立了流动注射氢化物发生-原子吸收光谱法测定高温镍基合金中痕量硒和锡的方法。样品用HNO3和HF经微波消解后,制成以EDTA作掩蔽剂的碱性溶液(pH12～13),用标准加入法测定。方法测定硒和锡的检出限分别为1.0μg     

Determination of Selenium and Tin in Human Brain by Graphite Furnace Atomic Absorption Spectrometry

 A method is reported for measuring Se and Sn in human brain tissue. The patients from whom the samples were taken had no diseases in their central nervous system. Microwave energy was applied to digest the brain samples. The digested samples were analyzed without dilution by transversely heated graphite atomizer for atomic absorption spectrometry with longitudinal Zeeman background correction. The dependence of integrated absorbance on various chemical modifiers has been examined. The most appropriate technique proved to be 5 μl sample injection using 20 μg prereduced palladium-nitrate for Se determination, and 20 μl sample injection applying 10 μg palladium-nitrate + 3 μg magnesium-nitrate for the measurements of Sn. The optimal temperature program was found to be 1200 °C pyrolysis and 2100 °C atomisation temperature for Se and 1500 °C pyrolysis and 2300 °C atomisation temperature for Sn. Accuracy of the applied techniques was tested by the analysis of standard reference materials. The precision was ±5% for Se and ±10% for Sn. The range of recovery values was 85–95% for Se and 95–105% for Sn. The mean Se concentrations in the investigated brain parts ranged from 200 to 700 ng/g, while the Sn concentrations were between 20 and 300 ng/g dry weight. Received October 3, 2000. Revision February 1, 2001.     

Catalytic Determination of Selenium in Human Hair by Polarography Using Glutathione

Abstract

A catalytic polarographic method has been proposed for the accurate determination of selenium in human hair. This method is based on the formation of Se(0)-GSH complex in alkaline medium which gives a catalytic reduction wave in polarography. The current observed is directly proportional to the amount of selenium present. The method has been applied for the determination of selenium in human hair and the recovery of added selenium from hair is found to be 97.5 to 102%. A suitable mechanism for the reduction process involving the catalytic reduction of oxidised glutathione is proposed.     

氢化物电热原子吸收法测定人血清中的硒

应用氢化物电热原子化装置测定了血清中的硒。采用这种技术可减少试样的基体干扰，提高分析灵敏度，而且具有良好的线性关系。方法测定灵敏度为１．２μｇ／Ｌ（１％吸收），检出限０．４μｇ／Ｌ变异系数６．３％，具有血量少、成本低、方法简便、精度好等优点。     

氢化物发生原子荧光法测定人发、玉米及辣椒中的砷

采用硝酸、高氯酸和硫酸湿法分解人发、玉米及辣椒,在盐酸介质中用硫脲-抗坏血酸将As(Ⅴ)还原为As(Ⅲ),氢化物发生原子荧光法测定,此法简便快速,相对标准偏差为2.4%。     

Determination of Inorganic and Total Arsenic in Wines by Hydride Generation Atomic Absorption Spectrometry

A method is described for the determination of inorganic arsenic species and total arsenic in wines by means of hydride generation atomic absorption spectrometry (HGAAS). Simple ethanol evaporation is the only pretreatment procedure proposed for wine samples prior to direct measurement of inorganic arsenic (AsIII) and As(V) species by HGAAS. The total arsenic content is determined after microwave digestion of the wine samples. The optimal parameters for the microwave digestion procedure and the next HGAAS measurement of arsenic are established. The detection limits achieved are 0.1µgL^–1 for inorganic and total arsenic determination. The relative standard deviation for both procedures and for ten independent determinations varied between 8 and 15% for arsenic species in the range of 1–30µgL^–1. The accuracy of the procedure for total arsenic determination was proved by comparative analysis using electrothermal atomic absorption spectrometry.     

氢化物电热原子吸收法测定人血清硒

氢化物原子吸收法是原子吸收分光光度法的一个重要分支。笔者应用氢化物电热原子化装置测定血清的硒具有用血量少，成本低，方便简便，精度佳等优点，适合一般医院开展科研和临床测定，采用这种技术可减少试样的基体干扰，提高了分析灵敏度，而且具有良好的线性关系，其测定检出限为1.2μg/L,纯度变异系数为6.3%。     

原子荧光光谱法测定区域地球化学调查样品中硒的干扰校正

氢化物发生-原子荧光光谱法(HG-AFS)是测定土壤样品中硒(Se)的理想方法,常用SePb合金材质的空心阴极灯为激发光源,无色散系统的AFS测硒时存在铅的光谱干扰,但尚未引起广泛关注。本文研究了高浓度Pb对硒测定的影响,并提出一种干扰校正的方法,可对检测结果进行有效校正。同时对还原剂浓度和消解酸的比例进行了优化,在2~40 ng/mL范围内获得Se标准曲线r2=0.9989,检出限为0.0023 ug/g,方法精密度为2.9-9.8%,准确度ΔlogC小于0.035。对南疆铁门关区域地球化学调查样品进行了测定,校正后Se的检测结果合格率为94.0%。此方法具有操作简单、准确高效,能够有效的校正样品中高浓度Pb的干扰,适合于大批量区域地球化学调查样品的检测。     

氢化物发生石墨炉原子吸收光谱法直接测定高温镍基合金中的硒

在６ｍｏｌ／Ｌ盐酸介质和０．１％ＫＢＨ４条件下，不但能有效地发生硒的氢化物，而且５ｍｇ／ｍｌＮｉ和３ｍｇ／ｍｌＦｅ都不干扰硒的测定。利用涂钯石墨；管作为氢化物的原子化器，直接测定了高温镍基合金中的硒，特征质量为４０ｐｇ，相对标准偏差在６．１％以内，回收率在９７％－１１０％之间。     

石墨探针-石墨炉原子吸收光谱法测定人发中痕量镍

石墨探针原子化技术是一种实现等温原子化和改善灵敏行之有效的方法，采用此方法对痕量镍的测定作了一系列条件试验，峰面积与镍浓度在０－２００ｎｇ／ｍＬ范围内呈线性关系，特征量为５１．８３ｐｇ，检出限为８６．８２ｐｇ，相对标准偏差为３．８６％。     

铟氢化物发生原子吸收方法研究

本文对铟氢化物发生方法进行了探讨，所采用的方法使铟氢化物的发生效率明显提高。在电加热石英管原子化器中得到的测定灵敏度为０．００７μｇ／（１％吸收），比文献报道值提高了一个数量级。并讨论了铟氢化物的发生机理与原子化机理。     

乳化剂OP存在下乙炔-空气火焰原子吸收法测定人发中锶

本文研究了八种表面活性剂对空气乙炔火焰中Ｓｒ原子吸收信号的影响，发现乳化剂ＯＰ能使Ｓｒ原子吸收信号增强５５％，同时还有降低和消除共存离子干扰的效果。采用６％（Ｖ／Ｖ）乳化剂ＯＰ为增敏剂测定了人发中痕量锶，回收率为９６～１０４％，相对标准偏差为２．５％。     

氢化物发生电热原子吸收法测定食品中微量锑铋

本文将电热氢化物原子吸收光谱技术应用于食品中微量锑铋测定,检出限可达ppb级。探讨了被测元素价态、预还原条件等因素对测定灵敏度的影响,并应用于罐头食品中微量锑铋分析。