4,5-二溴苯基萤光酮-溴化十六烷基三甲基铵——荧光光度法测定微量铌

本文研究了二溴苯基萤光酮-表面活性剂-铌三元体系的荧光特性,提出了以二溴苯基萤光酮-溴化十六烷基三甲基铵荧光光度法测定铌的新方法,该方法选择性和灵敏度以及重现性均很好,在λ_(ex)=420nm,λ_(em)=470 nm处铌含量在0～6μg/25ml范围内,线性关系良好、采用适当的掩蔽剂测定钢样中的微量铌,获得了满意的结果。     

2,4-二氯苯基萤光酮-溴化十六烷基三甲基铵分光光度测定钽

2,3,7-三羟基-9取代基萤光酮是胶束增敏分光光度法中一类高灵敏的显色剂,已有用水杨基萤光酮,二溴苯基萤光酮测定钽的报导,但直接测定均只是铌钽合量。我们用自行合成的九种不同9取代三羟基萤光酮,对铌和钽的测定性能作了系统的比较,从中筛选出灵敏度高、选择性好的2,4-二氯萤光酮,推荐作为测钽的优良试剂。因在2～3.6N高酸度下     

4,5-二溴邻硝基苯基萤光酮光度法测定有大量铌存在下微量钽的研究

本文研究了在柠檬酸-TritonX-100存在下,用4,5-二溴邻硝基苯基萤光酮在0.5—5M硫酸介质中光度法直接测定微量钽的高灵敏、高选择性方法。探讨了用过氧化氢-草酸掩蔽铌的最佳体系,铌的允许量可达150倍以上。用本法测定了氧化铌、铌铁,高温镍基合金和含铌钽矿样中的钽含量,结果令人满意。     

邻硝基苯基萤光酮-溴化十六烷基三甲基铵分光光度法测定微量钽

2,3,7-三羟基-9-取代萤光酮是一类金属离子的灵敏显色剂。用于测定钽的有水杨基萤光酮,二溴苯基萤光酮。邻硝基苯基萤光酮(O-NPF)只见用于铌的测定,未见用于测定钽。我们研究了在溴化十六烷基三甲铵存在下,有酒石酸(tar)作辅助配合剂,钽与O-NPF的显色反应。发现在0.1～0.3NHCl介质中,可获得稳定的橙红色配合物,其最大吸收波长为505nm。测得配合物的组成为Ta:tar:O-NPF=1:2:2,表现摩尔吸光系数ε_(505)=1.73×     

二溴苯基萤光酮──TritonX－100高灵敏分光光度法测定水中微量锰

二溴苯基萤光酮──ＴｒｉｔｏｎＸ－１００高灵敏分光光度法测定水中微量锰胡家元，何小蓓，杨素清（四川大学化学系，成都，６１００６４）关键词分光光度法，二溴苯基萤光酮，锰取代苯基萤光酮是一类应用十分广泛的高灵敏显色剂，近年已被用于许多金属离子的光度分析￣...     

用二溴苯基萤光酮和溴化十六烷基吡啶测定金属材料中的微量钛

钛(Ⅳ)比色方法较多,但高灵敏度的却少。文献报导了二溴苯基萤光酮(4,5-二溴2,3,7三羟基-9-苯基-6萤光酮)的酸碱性和光度特性。在羰基和三羟基邻位上引入溴原子,可以改善它的分析性质。溴三羟基萤光酮与三羟基萤光酮相比较,前者与金属离子的显色反应更为灵敏。实验部分主要仪器和试剂: 1.72型分光光度计。 2.HSD-2型酸度计。 3.钛(Ⅳ)标准溶液:称取纯二氧化钛0.1667g于瓷坩埚中,加3—4g焦硫酸钾熔融,稍冷用(5+95)硫酸浸取并移入量瓶中,用(5+95)硫酸稀至1升。使用时再稀释10倍,即10μgTi/ml。     

钛-2,3,7-三羟基萤光酮-阳离子表面活性剂胶束增敏显色反应的研究

本文研究了八种2,3,7-三羟基萤光酮-9-取代物(甲基、苯基、对-溴苯基-、对-二甲氨基-、间硝基苯基、对硝基苯基、水杨基以及β-羟基萘基)在阳离子表面活性剂存在下与钛的胶束增敏显色反应,结果发现,邻硝基苯基萤光酮与溴化十六烷基三甲基铵在0.1—0.35N的硫酸介质中,可以与钛形成灵敏度极高的红紫色络合物,其最大吸收峰位于542nm。络合物的表观摩尔吸光系数ε_(542)为2.10×10~5,为目前钛的显色反应中灵敏度最高的络合物,方法选择性良好,除铌与钽以外,其它金属阳离子均不影响钛的测定。利用上述显色反应,拟定了各种合金钢及纯铝中微量钛的分光光度测定法,并取得了令人满意的结果。     

阳离子表面活性剂存在下锗与2,3,7-三羟基-9-取代萤光酮显色反应的研究

本文研究了八种2,3,7-三羟基-9-取代荧光酮在阳离子表面活性剂存在下与锗的胶束增敏显色反应.发现水杨基萤光酮及邻硝基苯基萤光酮在强酸性介质中可以和溴化十六烷基三甲基铵形成高灵敏的胶束三元配合物.较详细地研究了用邻硝基苯基萤光酮与溴化十六烷基三甲基铵分光光度法测定微量锗的实验条件.并探讨了有关配合物的组成以及胶束增敏反应的机理.此法可不经分离,直接快速测定铅锌矿中的微量锗,结果比较满意.     

读者园地

问:见到有两种分子结构不同的苯基荧光酮试剂,但它们的简称都是二溴苯基荧光酮,为什么?湖南读者———马辉　　　　答:将苯基荧光酮(Phenylfluorone)的分子结构式和问题中的两种化合物的可能分子结构式图示如下:图1　苯基荧光酮及两种衍生物的结构式Fig .1　StructuralformulaofPFanditstwoderivatives化合物(a)的化学命名应为2 ,3,7 三羟基 9 苯基 6 荧光酮,简称苯基荧光酮(简写作PF)。化合物(b)应命名为2 ,3,7 三羟基 4 ,5 二溴 9 苯基 6 荧光酮,可简称为二溴苯基荧光酮(简写作DBPF)。化合物(c)应命名为2 ,3,7 三羟基 9 (3′,5′…     

新显色剂二甲氧基羟基苯基荧光酮光度法测定钼的研究

在表面活性剂存在下,利用2,3,7-三羟基荧光酮类试剂与钼形成配合物的显色反应灵敏度较高,选择性较好,因此该类试剂是光度法测定钼的一类重要显色剂。目前已报道有水杨基荧光酮、苯基荧光酮、二溴苯基荧光酮、二溴羟基苯基荧光酮、邻羟基萘基荧光酮等。为进一步研究这类试剂并提高其分析性能,本文合成了荧光酮试剂——二甲氧基羟基苯基荧光酮(DMH-PF),学名是2,3,7-三羟基-9-(3,5-二甲氧基-4-羟基)苯基荧光酮,其结构式为     

Microdetermination of some xylenols via investigation of their catalyzed reactions with iodine

The oxidation of some xylenols with iodine in aqueous ethanolic solutions in the presence of silver ions as a catalyst was investigated and used for microdetermination of these reductants. The study of these redox reactions and the microdetermination of these phenols were performed by volumetric and spectrophotometric methods. These methods were compared. The spectrophotometric method was more accurate at very low concentrations (60–488 μg). The volumetric methods used silver ions as catalyst. The potentiometric method is more accurate than the visual method. Possible schemes for the course of these redox reactions were suggested. One electron processes for oxidation of xylenols have been indicated.     

The catalyzed iodine-azide reaction in micro-analysis. II

Microchimica Acta - A method for the microdetermination of thiocyanate based on the measure of the nitrogen evolved in the catalyzed iodine-azide reaction is presented.     

The microdetermination of primary and secondary saturated nitrocompounds

Summary We have proposed a method for microdetermination of nitrogroups in primary and secondary saturated nitrocompounds based on reduction by hydriodic acid of the aci-form of the nitrocompound to the oxime.     

Remarques sur le microdosage du bore et du germanium dans les composes organiques et mineraux

A wet destruction in a Kjeldahl flask followed by spectrophotometric measurement with azomethine H as reagent, combustion in oxygen in a Parr bomb, and destruction by heating with sodium peroxide followed by acidimetric titration of the mannitol—boric acid complex have been tested for the microdetermination of boron in organic and inorganic compounds and compared with the Schöniger-flask method, which fails to give good results in the case of inorganic compounds; the wet-combustion method is the most useful. Similar techniques, combined with the acidimetric titration of the mannitol—germanic acid complex, or spectrophotometric measurement using phenylfluorone as a complexing reagent, or gravimetric determination as GeO₂, have been tested for the microdetermination of germanium, but none of them is entirely satisfactory, for reasons of lack of either universality or precision.     

Emploi du,cadion en chimie analytique : Un microdosage spectrophotométrique du mercure

A new method is described for spectrophotometric microdetermination of the mercury ion by means of a triazine dye, the “Cadion”. If the well-defined experimental conditions are maintained, the method is very sensitive and accurate. The influence of foreign ions is described.     

Microdetermination of the keto group by the oxime method

Summary A method was developed for microdetermination of the carbonyl group in ketones, esters of keto acids and also in diketones, capable of giving dioximes, by oximation of them with hydroxylamine hydrochloride in the presence of triethanolamine.     

Automatic coulometric method for the determination of carbon and hydrogen in organic substances

Conclusions A coulometric method is proposed for the microdetermination of carbon and hydrogen in organic substances.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 700–701, March, 1972.     

Microdetermination of copper using dithiooxamide crayons and the ring-oven technique

A method for the microdetermination of copper in air pollution investigations, using a dithiooxamide crayon and the ring-oven technique is presented. The limit of detection for the method is 0.04 μg, and the quantitative determination is applicable in the range of 0.05 to 0.5 μg of copper. The method is free from interferences that might be of significance in the study of air samples.     

Determination of 1,3-bis(4-hydroxyiminomethylpyridinium)-propane dichloride (TMB-4) with Pd(II)

The colour reaction of TMB-4 and palladium(II) chloride has been investigated. The optimum reaction conditions, spectral characteristics, stability constant and composition of the yellow water-soluble complex have been established. A new spectrophotometric method is proposed for microdetermination of TMB-4.     

Development and comparative evaluation of methods for the microdetermination of iodine in drugs of natural origin

Investigations have been made with the aim of drawing up a new and all-sided comparative evaluation of various known methods for the microdetermination of iodine in order to select the optimum procedures for the quantitative analysis of this element in materials of animal and plant origin. The efficacy of the use of the method of combustion in a flask with oxygen in the analysis of thyroidin and laminaria has been shown, and a new procedure for the microdetermination of iodine based on the combustion of a sample in oxygen and the determination of the iodine formed photometrically and by the starch-iodide reaction has been proposed.M. I. Sechenov First Moscow Medical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 278–286, March–April, 1987.