铋及氧化铋中微量碲的极谱催化波测定

金属铋中碲的含量在ppm级或在其以下,一般采用萃取-比色法测定,或用砷为载体还原沉淀法富集,这些方法对于处理不足微克量的碲并不理想。本文采用巯基棉在较大的酸度范围内把低至0.01μg的碲从铋中分离出来。对于微量碲的测定,极谱催化波具有较高的灵敏度,已报道的催化波体系有很多种,我们选择了0.6mol/L NH_4OH-0.01mol/L EDTA-0.3mol/L 酒石酸钠-5.7×10~(-5)mol/L Pb~(2+)-0.54mol/L Na_2SO_3体系,碲的峰电位为-1.16伏(SCE),该体系可允许一定量的铋存在,必要时还可同时测定试样中痕量硒,应用此法可     

P204萃取分离光度法测定纯铜中微量铋

纯铜中微量铋的测定,至今为止,大都采用以铁或锰作载体共沉淀与主体分离,然后采用KI或DDTC比色法完成测定。沉淀分离须进行多次,费时,并消耗大量试剂,这给分析工作者带来很大不便。本法于0.3mol/L硝酸溶液中,用二-2-乙基己基磷酸(简称P204)-正庚烷萃取铋使与主体铜分离,再用碘化钾-硫脲混合液反萃取铋,利用铋与碘离子的黄色络合物进行光度测定。经实践证明,该法简单快速,准确度高,选择性较好,适用于纯铜中微量铋的测定。     

巯基棉分离富集、石英缝管FAAS法测定河水中痕量铋

研究了巯基棉分离富集、单缝石英管FAAS法测定铋的最佳条件。以盐酸作介质,巯基棉富集铋的最佳吸附酸度为0．1－0．2mol/L(盐酸）,定量洗脱酸度为2mol/L(盐酸）。该法用于测定水中痕量的铋,回收率为96％－102％,相对标准偏差为4．8％。     

铋(Ⅲ)-芦丁体系的微分吸附计时电位法研究

提出一种测定痕量铋的微分吸附计时电位法.利用悬汞电极作工作电极,置富集电位于0.10 V,在0.015 mol/L HAc-0.005 mol/L NaAc-7.5×10-7 mol/L芦丁的底液中,测定铋(Ⅲ)的线性范围为1.0×10-10～7.5×10-8 mol/L,检出限为5×10-11 mol/L.探讨了影响方法灵敏度的主要因素,研究了电极过程.利用此法测定了中草药样品中的铋含量,结果满意.     

铋B-芦丁体系的微分吸附计时电位法研究

提出一种测定痕量铋的微分吸附计时电位法。利用悬汞电极作工作电极 ,置富集电位于 0 .10V ,在0 .0 15mol/LHAc 0 0 0 5mol/LNaAc 7.5× 10 -7mol/L芦丁的底液中 ,测定铋 的线性范围为 1.0× 10 -10 ～7 5× 10 -8mol/L ,检出限为 5× 10 -11mol/L。探讨了影响方法灵敏度的主要因素 ,研究了电极过程。利用此法测定了中草药样品中的铋含量 ,结果满意。     

硒碳糊电极微分电位溶出法测定铜和铋

建立了掺杂硒碳糊电极同时测定铜和铋的微分电位溶出法。在HCl(0.05mol/L)中,在-0.3V(vs.Ag/AgCl)下,Cu2+和Bi3+电沉积在电极表面,再在溶液中溶解氧的作用下,铜和铋从电极表面溶出,分别于0.30V和0.02V获得灵敏的电位溶出峰。微分电位溶出峰高(dt/dE)与铜和铋的浓度成线性关系,线性范围为5.0×10-9～1.55×10-7mol/L,检出限分别为4.0×10-9和2.5×10-9mol/L(S/N=3)。方法用于实际样品中铜和铋的测定,结果令人满意。     

DBF-偶氮氯膦分光光度法测定锡合金中的微量铋

在0.36mol/L硫酸-0.60mol/L磷酸介质中,铋与DBF偶氮氯膦形成配位比为1∶3的蓝色配合物,最大吸收波长为638nm,表观摩尔吸光系数为9.4×104L/(mol·cm),铋含量在0～1.2μg/mL内符合比耳定律,显色反应具有良好的选择性。用该方法测定锡标准样品中铋的含量,测定值与标准值基本一致,测定结果的相对标准偏差为2.3%～5.5%。     

反相萃取层析与光度法联用分离/测定中草药中微量铁的研究

研究了硅藻土-TBP反相萃取层析-分光光度法分离和测定微量铁的新方法.以0.30mol/L盐酸做流动相,以负载有磷酸三丁酯(TBP)的硅烷化白色担体为固定相,反相萃取层析法分离微量Fe(Ⅲ)与Co(Ⅲ)、Ge(Ⅳ)、Al(Ⅲ)、Cr(Ⅲ)、Mn(Ⅱ)、Ni(Ⅱ)等.在4.0mol/L盐酸介质中,铁与多种金属离子都被萃取在TBP柱上.用2mol/L盐酸洗脱部分离子,用0.30mol/L盐酸可定量地洗脱铁,然后用0.010mol/L盐酸可将柱上的其它离子洗脱.洗脱液中的铁用分光光度法测定.此方法可将铁与绝大部分干扰离子分离,并用于中草药中微量铁的分离和测定.     

铜膜差分脉冲阳极溶出伏安法测定药物中铋的含量

研究了铜膜电极代替汞膜电极测定重金属铋的差分脉冲溶出伏安法。实验了同位镀膜法测定铋的条件。在最佳实验条件下,Bi3+浓度在5×10-8~2×10-5mol/L范围内,其溶出峰峰高与浓度呈线性关系,检出限达到1×10-8mol/L。测定了一些药物中铋的含量,结果准确。     

铜-铋试剂配合物吸附波的研究

本文提出极谱测定微量铜的铜-铋试剂新体系。在0.064mol/L KOH,0.16mol/L NH_3·H_2O,1.28×10~(-4)mol/L铋试剂溶液中,铜(Ⅱ)-铋试剂配合物在单扫示波极谱上有一灵敏的配合物吸附波。铜浓度在8×10~(-9)～8×10~(-7)g/ml范围内与导数波高成良好的线性关系。将该休系应用于铝合金中痕量铜的测定,结果满意。     

Optimization of a single-drop microextraction method for multielemental determination by electrothermal vaporization inductively coupled plasma mass spectrometry following in situ vapor generation

A headspace single-drop microextraction (HS-SDME) method has been developed in combination with electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICP-MS) for the simultaneous determination of As, Sb, Bi, Pb, Sn and Hg in aqueous solutions. Vapor generation is carried out in a 40 mL volume closed-vial containing a solution with the target analytes in hydrochloric acid and potassium ferricyanide medium. Hydrides (As, Sb, Bi, Pb, Sn) and Hg vapor are trapped onto an aqueous single drop (3 µL volume) containing Pd(II), followed by the subsequent injection in the ETV. Experimental variables such as medium composition, sodium tetrahydroborate (III) volume and concentration, stirring rate, extraction time, sample volume, ascorbic acid concentration and palladium amount in the drop were fully optimized. The limits of detection (LOD) (3σ criterion) of the proposed method for As, Sb, Bi, Pb, Sn and Hg were 0.2, 0.04, 0.01, 0.07, 0.09 and 0.8 µg/L, respectively. Enrichment factors of 9, 85, 138, 130, 37 and 72 for As, Sb, Bi, Pb, Sn and Hg, respectively, were achieved in 210 s. The relative standard deviations (N = 5) ranged from 4 to 8%. The proposed HS-SDME-ETV-ICP-MS method has been applied for the determination of As, Sb, Bi, Pb, Sn and Hg in NWRI TM-28.3 certified reference material.     

A novel approach for an automated liquid/liquid extraction system—principle and application for the determination of several trace contaminants in highly alloyed steels and base alloys

A novel automated liquid/liquid extraction system was developed for the determination of trace contaminants in unalloyed, alloyed and highly alloyed steels and super alloys. In the presented batch extraction system the aqueous phase and the non-water miscible organic phase were brought into close phase contact by high-speed stirring with a magnetic stir bar. Iodide complexes of Ag, Bi, Cd, Pb, Sb, Sn, Tl, and Zn were extracted from aqueous steel digests into 4-methylpentan-2-one (MIBK) containing 20 g L⁻¹ trioctylphosphine oxide. Ag, Bi, Cd, Pb, and Tl were extracted quantitatively whereas the extraction yields of Sb, Sn, and Zn were 83%, 61% and 75% respectively. Using high resolution continuum source flame AAS (HR-CS-FAAS) for analyte quantification the method was validated using 21 certified steel reference materials (CRMs).     

化学蒸气发生-四通道原子荧光光谱法同时测定高纯金中的痕量As,Sb,Bi,Te

采用化学蒸气发生-四通道原子荧光光谱法测定了高纯金中的痕量砷、锑、铋和碲。用乙酸乙脂萃取分离金,水相还原后采用化学蒸气发生-四通道原子荧光光谱法测定高纯金中的痕量砷、锑、铋和碲。在最佳条件下,方法对As,Sb,Bi,Te的检出限分别为0.04,0.05,0.04,0.03 ng/mL(3σ);测定精密度分别为0.98,0.89,0.94,0.99%(对10 ng/mL As,Sb,Bi和Te混合标准,n=7)。方法对实际样品中的As,Sb,Bi,Te进行了同时测定,测定结果与标准方法无明显差异,各元素的加标回收率为95%～105%。     

Behaviour of the dithiocarbamate complexes of arsenic, antimony, bismuth, mercury, lead, tin and selenium in methanol with a hydride generator

A study was carried out with a continuous hydride generator coupled to an atomic emission spectrometer with inductively-coupled plasma to determine whether hydrides of As, Bi, Pb, Sb, Sn and Se and mercury vapor could be generated in methanol solutions of their dithiocarbamate complexes. It was found that (with the exception of Pb) hydride generation with sufficient efficiency for simultaneous multi-element determination is achieved using 0.25% NaBH(4)-0.6 mol 1(-1) HCl as reaction medium. The detection limit was found to be 0.2 ng ml(-1) for As, 30 ng ml(-1) for Bi, 0.03 ng ml(-1) for Se, Sb and Sn.     

Simultaneous determination of arsenic, antimony, bismuth and mercury in geological materials by vapor generation-four-channel non-dispersive atomic fluorescence spectrometry

Chemical vapor generation (CVG) coupled with non-dispersive atomic fluorescence spectrometry (NDAFS) has been widely used for determination of vapor-forming elements, but most of such works have been focused on single element analysis, and reports dealing with more than three elements simultaneous determination by CVG-NDAFS are rare. In this work, a sensitive and robust analytical procedure for the simultaneous determination of arsenic, antimony, bismuth and mercury in geological materials using vapor generation-four-channel non-dispersive atomic fluorescence spectrometry has been developed. The conditions of instrumentation and vapor generation of arsenic, antimony, bismuth and mercury were optimized. The optimized concentrations of KBH(4) and HCl required for analytes generation were 1.3% (m/v) and 20% (v/v), respectively. The interferences of coexisting ions and mutual hydride interferences were investigated carefully. One thousand milligrams per litre of Fe(3+); 500mgl(-1) of Pb(2+), Zn(2+), Mn(2+); 50mgl(-1) Cu(2+), Ni(2+), Cr(6+), Co(2+); 10mgl(-1) Ag(+) and 5mgl(-1) Au(3+) does not interfere with the determination of As, Sb, Bi and Hg. Associating a dilution of 1:250 (m/v) in the procedure of sample pretreatment, the tolerant concentrations of As, Sb, Bi and Hg in real geological materials are 2500, 1000, 250 and 5000ppm, respectively. Under optimal conditions, the detection limits for As, Sb, Bi and Hg were determined to be 0.068, 0.047, 0.037 and 0.008ngml(-1), respectively. The precisions for seven replicate determinations at the 5ngml(-1) of As, Sb, Bi and 1ngml(-1) of Hg were 0.47, 0.60, 0.97 and 0.93% (R.S.D.), respectively. Sample digestion was carried out on 500mg sample with 3ml HNO(3) and 10ml HCl, followed by addition of thiourea solution for the quantitative reduction of As(V), Sb(V) to As(III), Sb(III). The proposed method was successfully applied to the simultaneous determination of As, Sb, Bi and Hg in a series of certified geological reference materials using simple aqueous standard calibration technique. The results obtained are in good agreement with the certified values.     

氢化物发生(HG)-ICP-AES测定中药漏芦中微量砷、锑、铋的研究

提出氢化物发生等离子体原子发射光谱（ＨＥ－ＩＣＰ－ＡＥＳ）值接测定中药漏芦中微量Ａｓ、Ｓｂ、Ｂｉ的方法。对影响分析信号的主要工作条件进行了选择和优化,对干扰元素及消除方法进行了考察。方法的检出限Ａｓ、Ｓｂ、Ｂｉ分别为２．７、３．４、２．８ｎｇ／ｇ,精密度（ＲＳＤ）为２．１％～５．０％,试样加入平均回收率为９２．５％～１０６．５％,本法用于中药漏芦的分析,结果满意。     

Determination of tin, bismuth, antimony, indium, gallium and arsenic by solvent extraction cum atomic absorption spectrophotometry

A rapid atomic absorption spectrometric method for the determination of tin, antimony, bismuth, indium, gallium and arsenic in geological materials, steels and alloys is described. The samples are fused with sodium peroxide (for geological samples such as cassiterite and sulphides) or decomposed with sulphuric/hydrochloric acid mixture or by alkaline fusion (for silicates or bauxites) or by acid treatment (for steels, alloys and certain geological samples). The elements of interest are extracted as their iodides into methyl isobutyl ketone, stripped into aqueous solution by treatment with benzene, concentrated nitric acid and water, and determined by flame atomic-absorption spectrometry. Detailed study is made on stripping of the metals from organic phase as there no simple and rapid stripping procedures available. The method allows the determination of Sn, Sb, Bi and In down to 2 ppm and Ga down to 5 ppm. The relative standard deviations range up to 10% with an average of 2.5%. Apparent recoveries of these metals range from 90 to 110 with an average of 95% for Sb and 99% for others.     

Development of gas-phase sample-introduction techniques for analytical atomic spectrometry.

For the last 30 years, several types of gas-phase sample-introduction methods in analytical atomic spectrometry, i.e., atomic absorption spectrometry (AAS), atomic emission spectrometry (AES) and atomic fluorescence spectrometry (AFS), have been investigated and developed in the author's laboratory. Their fundamental results are summarized in this review article. The gas-phase sample-introduction techniques developed in the author's laboratory can be roughly divided into four groups: i) hydride generation, ii) cold-vapor generation of mercury, iii) analyte volatilization reactions and iv) miscellaneous. The analytical figures of merit of the gas-phase sample-introduction methods have been described in detail. Hydride generation has been coupled with the AAS of As, Bi, Ge, Pb, Sb, Se, Sn and Te, with the inductively coupled plasma (ICP) AES of As, Bi, Sn, Se and Sb, with the high-power nitrogen microwave-induced plasma (N2-MIP) AES of As, Bi, Pb, Sb, Se, Sn and Te by their single- and multi-element determinations, with the AFS of As, Bi, Pb, Sb, Se, Sn and Te, and with the ICP mass spectrometry (MS) of As and Se. The cold-vapor generation method for Hg has been combined with atmospheric-pressure helium microwave-induced plasma (He- or Ar-MIP)-AES and AFS. Furthermore, analyte volatilization reactions have been employed in the ICP-AES of iodine, in the He-MIP-AES of iodine bromine, chlorine, sulfur and carbon, and in the ICP-MS of sulfur. As a result, when compared with conventional solution nebulization, a great improvement in the sensitivity has been attained in each instance. In addition, the developed techniques coupled with analytical atomic spectrometry have been successfully applied to the determination of trace elements in a variety of practical samples.     

ICP-MS – A powerful analytical technique for the analysis of traces of Sb, Bi, Pb, Sn and P in steel

The determination of Sb, Bi, Sn, Pb and P in steel using quadrupole- and double-focusing-sector-field-ICP-MS is described. Simple and fast methods for sample preparation were developed with regard to requirements of ICP-MS. Several certified steel reference materials were analyzed in order to verify the accuracy and precision of the applied methods. Received: 22 April 1997 / Revised: 19 June 1997 / Accepted: 23 June 1997