DBF-偶氮氯膦分光光度法富集测定水中痕量铋

铋是环境中的稀有分散元素，在地壳中的丰度约为0．2mg／L，海水和天然水中也有铋存在。铋对人体是有毒元素，主要积累在哺乳动物的肾脏，造成病变。白鼠试验表明，1．5mg／d有中毒症状，160mg／d中毒致死，用含铋27mg／L的废水浇灌农作物，会使农作物中毒枯死，因此有必要探索水样中铋含量的测定方法。水样中铋含量测定可采用三波长吸光光度法，但该方法对仪器精度要求较高。近几年，一些新的不对称变色酸双偶氮衍生物试剂成为光度法测定铋的重要显色剂，该类方法具有分析速度快、灵敏度和选择性较高的特点。笔者利用DBF-偶氮氯膦分光光度法测定水样中的铋含量，该法未见文献报道。     

铜电解液中锑铋的测定

电解液中锑、铋通常以沉淀法富集分离后,用碘化钾光度法测定铋;用结晶紫萃取光度法测定锑,方法不甚简便。锑、铋与碘化钾和硫脲均能生成黄色络合物,可用作各自的光度法测定,但两元素相互干扰严重。我们考察了酸度对锑、铋与碘化钾和硫脲络合物显色的影响。试验结果如图所示,铋络合物显色不受酸度影响,而锑络合物显色则明显受酸度影响。在     

EDTA络合滴定法测定易熔合金中高含量铋

易熔合金化学成分主要由锡、铅、铋三元素组成 ,熔点低 ,是一种新型优质焊料。EBiPb30 2 0易熔合金中含铋为 5 0 % ,铅为 30 % ,锡为 2 0 %。国家标准方法中 ,硫脲光度法、碘化钾光度法只能测定低含量的铋 (<1.0 0 % ) ,高含量铋 (>1.0 0 % )的测定未见报道。本法根据络合滴定原理 ,测定了易熔合金中的铋 ,样品分析结果及加标回收率结果均很好。1　试验部分1.1　主要试剂铋标准溶液 :0 .0 2g·ml- 1,称取金属铋(99.99% ) 2 .0 0 0 0g置于 2 5 0ml烧杯中 ,加硝酸 (1+1) 6 0ml,加热溶解 ,煮沸驱除氮的氧化物后 ,冷却 ,移入 10 0ml容量瓶中 …     

催化动力学光度法对食品中痕量元素分析的研究进展

随着人们生活水平的不断提高,食品中痕量元素的含量越来越引起人们的关注.综述了近十年来催化动力学光度法在食品分析中对痕量元素进行测定的研究情况,并对催化动力学光度法在食品分析中的应用前景和研究方向进行了展望.     

溴邻苯三酚红光度法测定矿石中铋

近期亦有新试剂光度法测定铋的报导,但目前在实际工作中仍以碘化物法与硫脲法为主。因而开展光度法测定铋的研究很有必要。为此曾提出过在溴化十六烷基吡啶存在下,以溴邻苯三酚红(BPR)     

离子交换树脂相分光光度法测定水中痕量铋

利用离子交换树脂相通过光度法测定痕量铋。铋离子在碱性介质中与邻苯二酚紫形成紫色络合物将其富集在苯乙烯阴离子交换树脂上,通过制作成薄层直接光度法测定。本法操作简便,装皿容易,选择性好,精密度高(测定5μgBi3 5次,RSD=3.8%),铋浓度在0~10μg(50ml)时与吸光度呈线性关系,线性回归方程为A=0.010 0.075C(μg/50ml),相关系数r=0.9997,铋的回收率为98%~99%,检出限为3.2μg/L,用于水中痕量铋的测定,结果满意。     

新显色剂偶氮氯膦-DBM与铋显色反应的研究

本文系统地报道了偶氮氯膦-DBM(简称DBMPA)的合成及其与铋在纯高氯酸水溶液,水与乙醇混合溶液及正丁醇等介质中的显色反应。在纯高氯酸水溶液中配合物的表观摩尔吸光系数为8.2×10~4L.mol~(-1).cm~(-1)。加入乙醇后增至1.2×10~5L.mol~(-1).cm~(-1)。与水不相混溶的醇类可将DBMPA及其与铋的配合物萃取入有机相而进一步提高灵敏度。用拟定的直接光度法及萃取光度法测定了铜合金、锌基合金及纯铝中的微量铋,结果令人满意。     

吸光光度法连续测定铜电解液中微量锑和铋

在多数情况下 ,锑和铋以有害痕量元素存在于电解液和金属材料中。在铜电解液中 ,锑和铋的含量决定电解铜的质量 ,当它们的含量达到一定值时 ,电解池中阳极 (粗铜 )的残极率上升 ,同时阴极 (精铜 )表面起瘤 ,从而造成精铜纯度下降 ,故需严格控制锑和铋的含量[1 ] 。吸光光度法测定锑和铋的方法虽有不少报道 ,但大多数是单独测定锑或铋 ,连续测定锑和铋[2 ] 的方法也有报道。为了提高分析速度 ,本文在文献 [3]的基础上 ,研究了在聚乙烯醇存在下 ,硫脲和硫氰酸钾掩蔽 Cu( )等干扰离子 ,碘化钾吸光光度法连续测定锑和铋的含量 ,操作简便 ,线性…     

BiI~-_4选择电极测定金属中铋

铋(Ⅲ)与碘化钾形成的深黄色络合物BiI_4~-已用于络合滴定法和光度法中测定铋。金属中痕量铋一般用DDTCC或烷基磷酸萃取后进行光度测定。我们以自制的PVC膜、BiI_4~-选择电极作指示电极电位滴定了合金中的铋,并以二-(2-乙基己基)磷酸(P204)萃取分离后用标准加入法测试有色金属中痕量铋,结果均较为满意。     

阻抑动力学光度法测定水样中的痕量铋

基于弱酸介质中, 在十二烷基磺酸钠(SDS)存在下, 痕量Bi3 对H2O2氧化结晶紫(CV)的褪色反应有明显的阻抑作用, 建立了测定痕量Bi3 的阻抑动力学光度法, 研究了该反应的最佳实验条件和动力学参数. 结果表明, 该方法检出限为2.77×10-8 g/L, 线性范围为0～0.008 μg/mL. 可用于环境水样中铋的测定.     

Identification, isolation, and characterization of cysteinate and thiolactate complexes of bismuth

Although bismuth compounds have been used in medicine for over 200 years, chemical characterization of complexes involving biological molecules is minimal and mechanisms of bioactivity are ill-defined. The thiophilic nature of bismuth implicates sulfur centers as likely sites for interaction, and we have exploited this feature to identify, isolate, and characterize complexes of bismuth with thiolate-carboxylate bifunctional ligands including the amino acid l-cysteine. The solid-state structures of potassium dichloro(thiopropionato)bismuth (K[1d]), dimethylaminoethanethiolato(thiopropionato)bismuth (4), and dinitrato(cysteinato)bismuthphenanthroline [5(phen)] are compared with data from electrospray ionization mass spectrometry (ESI-MS). ESI-MS is applied to reactions of BiCl(3) or Bi(NO(3))(3) with mercaptosuccinic, malic, and succinic acids to illustrate the general observation of 1:1 and 1:2 complexes.     

Synthesis,structure and reactivity of complexes containing a transition metal–bismuth bond

The transition metal chemistry of bismuth has attracted significant interest since the 1970s. The low cost and high abundance of bismuth(III) reagents, such as the trihalides, makes them ideal starting materials and the size of the bismuth centre allows three- and higher-coordinate complexes to be synthesised, in which the bismuth atom is linked to one or more transition metal fragments. The ability to vary these metal fragments gives access to a plethora of available structures, with cyclopentadienylcarbonyl, metal carbonyl and sandwich compounds of bismuth in existence. Significant recent study has focused on applications in catalysis, where bismuth species can act as cross-coupling agents in carbon–carbon, carbon–nitrogen and carbon–oxygen bond forming reactions. Another striking feature is the variation in bonding situations that can be observed when studying the organometallic chemistry of bismuth. For example, dative and covalent interactions have been reported, in addition to cases of dibismuth acting as a two-, four- or six-electron donating ligand. This review aims to demonstrate the multi-faceted nature of the transition metal chemistry of bismuth and provide a detailed coverage of this topic.     

Reactions between alkaloids and bismuth iodide,the compounds formed and their analytical application : A heterometric study

The reactions between nitron, quinine, cinchonine, strychnine, sparteine, papaverine, rivanol, acriflavine, phenanthroline, antipyrine and atropine with bismuth nitrate in potassium iodide solution were studied heterometrically. The individual structure of the N-compounds was discussed on the basis of the reactions and the large salt-compounds obtained 0.5 to 1 mg of N-compound was necessary for a determination which lasted 10–15 min. The errors in almost all cases were negligible 0.3–0.5 mg bismuth could also be determined by the titration of bismuth with N-compounds and the error was negligible.     

Reaction of a mixture of bismuth and iron oxides with chlorine and sulfur dioxide

The processes in a heterogenous multicomponent system Bi₂O₃-Fe₂O₃-Cl₂-SO₂. are explored. In the temperature range 300–700°C is clearly developed mutual influence of chemical reactions at introducing to the system of an additional component: chloridosublimation of both bismuth and iron in the presence of SO₂ and chloridosublimation of bismuth at adding iron oxide to bismuth oxide are accelerated. In the region of the higher temperatures the possible chemical reactions in the system proceed independently: SO₂ only dilutes chlorine and mutual influence of bismuth and iron oxides is not found.     

The studies of the reaction of bismuth(III) with iodide at nanogram level by thermal lensing

By the example of the analytical system based on the reaction of bismuth with iodide, it is shown that thermal lens spectrometry can be used for studying changes in analytical reactions at the nanogram level of reactants. The stability constants of bismuth(III) iodides at the concentration level are found. The solubility constants of iodides of metals interfering with bismuth determination are estimated. It is shown that the due regard to the new conditions could enhance the sensitivity and selectivity of determination.     

Applications of bismuth(III) compounds in organic synthesis

This review article summarizes the applications of bismuth(III) compounds in organic synthesis since 2002. Although there are an increasing number of reports on applications of bismuth(III) salts in polymerization reactions, and their importance is acknowledged, they are not included in this review. This review is largely organized by the reaction type although some reactions can clearly be placed in multiple sections. While every effort has been made to include all relevant reports in this field, any omission is inadvertent and we apologize in advance for the same (358 references).     

水相金属有机化学

本文对近年来锡、锌、铋等介入下的水相金属有机化学作了综述。特别对水相Barbier 反应作了较详细的介绍, 同时也描述了一些典型的水相金属有机反应,如Immonium 阳离子的烷基化反应, α, β 不饱和化合物的共轭加成, 醇醛缩合反应及水溶性金属有机化合物的反应等。某些反应的机理也被讨论。     

Charged particle activation analysis applied to the detection of heavy elements

Trace analysis methods have been developed for determining thallium, lead and bismuth. Proton or deuteron activation is used followed by a radiochemical separation of the reaction products:²⁰³Pb from thallium,²⁰⁶Bi from lead, and²⁰⁷Po from bismuth. Activation curves are presented for different nuclear reactions occuring on the elements studied. Determinations have been carried out on high purity samples containing varying amounts of thallium, lead, and bismuth. Based on experimental data, the detection limits are estimated at 0.01 ppm for lead, and 0.001 ppm for thallium and bismuth, respectively.     

Bismuth triflate-chiral bipyridine complexes as water-compatible chiral Lewis acids

[reaction: see text] Catalytic asymmetric hydroxymethylation of silicon enolates with an aqueous formaldehyde solution has been developed using a chiral bismuth complex. This is the first example of highly enantioselective reactions using a chiral bismuth catalyst in aqueous media. In this paper, we have added Bi(OTf)(3)-1 complex as a "water-compatible Lewis acid". Bi(OTf)3 is unstable in the presence of water but is stabilized by the basic ligand.     

Ex Situ Scanning Electrochemical Microscopy (SECM) Investigation of Bismuth‐ and Bismuth/Lead Alloy Film‐Modified Gold Electrodes in Alkaline Medium

Scanning electrochemical microscopy (SECM) in feedback mode was employed to characterise the reactivity and microscopic peculiarities of bismuth and bismuth/lead alloys plated onto gold disk substrates in 0.1 mol L^?1 NaOH solutions. Methyl viologen was used as redox mediator, while a platinum microelectrode was employed as the SECM tip. The metal films were electrodeposited ex situ from NaOH solutions containing either bismuth ions only or both bismuth and lead ions. Approach curves and SECM images indicated that the metal films were conductive and locally reactive with oxygen to provide Bi³⁺ and Pb²⁺ ions. The occurrence of the latter chemical reactions was verified by local anodic stripping voltammetry (ASV) at the substrate solution interface by using a mercury‐coated platinum SECM tip. The latter types of measurements allowed also verifying that lead was not uniformly distributed onto the bismuth film electrode substrate. These findings were confirmed by scanning electron microscopy images. The surface heterogeneity produced during the metal deposition process, however, did not affect the analytical performance of the bismuth coated gold electrode in anodic stripping voltammetry for the determination of lead in alkaline media, even in aerated aqueous solutions. Under the latter conditions, stripping peak currents proportional to lead concentration with a satisfactory reproducibility (within 5 % RSD) were obtained.