Bismuth analysis

Recently, W. K. Fischer gave a review of The evolution of surfactant concentrations in German natural waters 1960-1980 [83], following earlier investigations [84] carried out over many years. In addition to the concentration of anionic surfactants obtained by the methylene blue analysis (MBAS), it has also been possible (from 1972) to monitor the values for nonionic surfactants present in natural waters, with the bismuth analysis (BiAS). Fischer found that in the Rhine and in its tributaries, an overall steep decrease of concentrations took place, down to very small residual values (about 0.02-0.1 mg of MBAS/1) as a yearly average, which were only rarely exceeded. He found a significant correlation to the extension of biological treatment plants, which had been carried out in this period. 

Bismuth Tribromide. Bismuth(III) bromide is a hygroscopic, golden-yeUow, crystalline soHd made up of pyramidal molecules. X-ray analysis has shown that the three bromines are 0.263 0.002 nm from the bismuth and the Br—Bi—Br angles are 100 4°. More recent nqr experiments indicate that the bromines are not equivalent (20). The soHd has a density of 5.72 g/mL and that of the Hquid is 4.572 g/mL at 271.5°C. 

At present time the use of oxide single erystals sueh as bismuth germanate (Bi Ge O, ) and pai atellurite (TeO,) as deteetors in opto-eleetronies stimulate produetion of high purity Bi, Te, Ge and their oxides Bi O, GeO, TeO,. This requires development of analytieal teehniques for purity eontrol of these materials. For survey traee analysis atomie emission speetrometry (AES) and mass speetrometry (MS) with induetively eoupled plasma (ICP) is widely used. However, the deteetion limits of impurities aehievable by these methods for the analysis of high purity solids are limited by neeessity of sample dissolution in pure aeids and dilution up to 5 10 times for ICP-MS and 50-100 for ICP-AES. One of the most effeetive ways to improve the analytieal performanees of these methods is pre-eoneentration of miero-elements. 

Copper (II), Bismuth (III) and lead (II), ai e important elements in the environment and they have essential roles in different biologieal systems. Lead is widely distributed in nature and exhibits severe deleterious effeets on human [1]. Copper is an essential element for the normal metabolism of many living organisms. Bismuth has been used in medieines for the treatment of helieobaeter pylorie-indueed gastritis [2, 3]. Therefore traee analysis of these elements is important for monitoring their eoneentration in the environment. 

This approach is an alternative to quantitative metallography and in the hands of a master gives even more accurate results than the rival method. A more recent development (Chen and Spaepen 1991) is the analysis of the isothermal curve when a material which may be properly amorphous or else nanocrystalline (e.g., a bismuth film vapour-deposited at low temperature) is annealed. The form of the isotherm allows one to distinguish nucleation and growth of a crystalline phase, from the growth of a preexisting nanocrystalline structure. 

Aqueous ceric solutions are widely used as oxidants in quantitative analysis they can be prepared by the oxidation of Ce ( cerous ) solutions with strong oxidizing agents such as peroxodisulfate, S20g ", or bismuthate, BiOg". Complexation and hydrolysis combine to render (Ce" +/Ce +) markedly dependent on anion and acid concentration. In relatively strong perchloric acid the aquo ion is present but in other acids coordination of the anion is likely. Also, if the pH is increased, hydrolysis to... 

WEB The active ingredient in Pepto-Bismol (an over-the-counter remedy for upset stomach) is bismuth subsalicylate, C7H5Bi04. Analysis of a 1.500-g sample of Pepto-Bismol yields 346 mg of bismuth. What percent by mass is bismuth subsalicylate (Assume that there is no other bismuth-containing compound in Pepto-Bismol.)... 

DETERMINATION OF BISMUTH, CADMIUM AND LEAD IN A MIXTURE ANALYSIS OF A LOW-MELTING ALLOY... 

Analytical electron microscopy permits structural and chemical analyses of catalyst areas nearly 1000 times smaller than those studied by conventional bulk analysis techniques. Quantitative x-ray analyses of bismuth molybdates are shown from lOnm diameter regions to better than 5% relative accuracy for the elements 61 and Mo. Digital x-ray images show qualitative 2-dimensional distributions of elements with a lateral spatial resolution of lOnm in supported Pd catalysts and ZSM-5 zeolites. Fine structure in CuLj 2 edges from electron energy loss spectroscopy indicate d>ether the copper is in the form of Cu metal or Cu oxide. These techniques should prove to be of great utility for the analysis of active phases, promoters, and poisons. 

Several previous studies have demonstrated the power of AEH in various catalyst systems (1-11). Often AEM can provide reasons for variations in activity and selectivity during catalyst aging by providing information about the location of the elements involved in the active catalyst, promoter, or poison. In some cases, direct quantitative correlations of AEM analysis and catalyst performance can be made. This paper first reviews some of the techniques for AEM analysis of catalysts and then provides some descriptions of applications to bismuth molybdates, Pd on carbon, zeolites, and Cu/ZnO catalysts. 

After adjusting to 2 mol 1 1 in hydrochloric acid, 500 ml of the sample is adsorbed on a column of Dowex 1-XS resin (Cl form) and elution is then effected with 2 M nitric acid. The solution is evaporated to dryness after adding 1M hydrochloric acid, and the tin is again adsorbed on the same column. Tin is eluted with 2 M nitric acid, and determined in the eluate by the spectrophotometric catechol violet method. There is no interference from 0.1 mg of aluminium, manganese, nickel, copper, zinc, arsenic, cadmium, bismuth, or uranium any titanium, zirconium, or antimony are removed by ion exchange. Filtration of the sample through a Millipore filter does not affect the results, which are in agreement with those obtained by neutron activation analysis. 

Tseng et al. [69] determined 60cobalt in seawater by successive extractions with tris(pyrrolidine dithiocarbamate) bismuth (III) and ammonium pyrrolidine dithiocarbamate and back-extraction with bismuth (III). Filtered seawater adjusted to pH 1.0-1.5 was extracted with chloroform and 0.01 M tris(pyrrolidine dithiocarbamate) bismuth (III) to remove certain metallic contaminants. The aqueous residue was adjusted to pH 4.5 and re-extracted with chloroform and 2% ammonium pyrrolidine thiocarbamate, to remove cobalt. Back-extraction with bismuth (III) solution removed further trace elements. The organic phase was dried under infrared and counted in a ger-manium/lithium detector coupled to a 4096 channel pulse height analyser. Indicated recovery was 96%, and the analysis time excluding counting was 50-min per sample. 

All of the organohalogen compounds studied were commercial products obtained from various manufacturers and used as received. Only the DBDPO was purified further by recrystallization for some of the chromatography and thermal analysis experiments. Samples of antimony trioxide and antimony pentoxide were also obtained from commercial sources. The ultrapure antimony trioxide, bismuth trioxide, bismuth metal, antimony metal, dibenzofuran and diphenyl ether were all obtained from Aldrich Chemicals. The poly(propylene) (PP) resin was 0.7 mfi, food grade from Novamont and the poly(ethylene) was unstabilized, high molecular weight, HDPE from American Hoechst. 

Previous thermal analysis studies had indicated that while Sb203 did not react directly with DBDPO, there was some evidence that the reaction of a polymer substrate with the Sb203 generated a species which was very reactive (23), and that this product was antimony metal (Sb°). Therefore, simple mixtures of DBDPO with powdered antimony, bismuth and zinc metals (mole ratio of bromine to metal of 3 1) were pyrolyzed and the extent of reaction determined by CGC. 

The aryl-substituted derivatives of [Bi(SeC6H2R3-2,4,6)3] (R = Me, Pr, Bu) are the only isolated examples of selenolate complexes. They have been characterized by mp, elemental analysis, NMR spectroscopy, and thermal gravimetric analysis, and the solid-state structure of the isopropyl-substituted derivative reveals a tricoordinate environment for bismuth [Bi-Se 2.630(8)-2.711(8) A Se-Bi-Se 92.3(2)-103.3(2)°], imposed by the steric bulk of the ligands (38). 

Widespread medicinal use of colloidal bismuth subcitrate (CBS) has prompted extensive studies of bismuth compounds involving the citrate anion. Bismuth citrate is essentially insoluble in water, but a dramatic increase in solubility with increasing pH has been exploited as a bio-ready source of soluble bismuth, a material referred to as CBS. Formulation of these solutions is complicated by the variability of the bismuth anion stoichiometry, the presence of potassium and/ or ammonium cations, the susceptibility of bismuth to oxygenation to Bi=0, and the incorporation of water in isolated solids. Consequently, a variety of formulas are classified in the literature as CBS. Solids isolated from various, often ill-defined combinations of bismuth citrate, citric acid, potassium hydroxide, or ammonium hydroxide have been assigned formulas on the basis of elemental analysis data or by determination of water and ammonia content, but are of low significance in the absence of complementary data other than thermal analysis (163), infrared spectroscopy (163), or NMR spectroscopy (164). In this context, the Merck index lists the chemical formula of CBS as KgfNHJaBieOafOHMCeHsCbh in the 11th edition (165), but in the most recent edition provides a less precise name, tripotassium dicitrato bismuthate (166). 

Bis(monofluoro)-triazine dyes, 9 473 Bismuth (Bi) 4 1-16. See also Bismuth alloys Bismuth compounds analysis, 4 10 barium alloys with, 3 344 catalyst poison, 5 257t economic aspects, 4 6-9 environmental concerns, 4 10-11 fabrication, 4 4-5 health and safety factors, 4 10-11 manufacture and processing, 4 3-6 mine and refinery production by country, 4 8t... 

Bismuth(III) bromide, 4 21 Bismuth bromide sulfide (19 3 27), 4 24 Bismuth bromosulfide, 4 24 Bismuth carboxylates, 4 25 Bismuth chloride, 4 6 Bismuth(III) chloride, 4 19-20 Bismuth chlorosulfide, 4 24 Bismuth compounds, 4 16-43 alloy-like superconducting, 4 18t analysis, 4 17... 

Analytical electron microscopy of individual catalyst particles provides much more information than just particle size and shape. The scanning transmission electron microscope (STEM) with analytical facilities allows chemical analysis and electron diffraction patterns to be obtained from areas on the order of lOnm in diameter. In this paper, examples of high spatial resolution chemical analysis by x-ray emission spectroscopy are drawn from supported Pd, bismuth and ferric molybdates, and ZSM-5 zeolite. 

Owing to the toxicity of mercury and its disposal problem, solid electrodes are now very popular. In particular, electrodes made of carbon such as glassy carbon, graphite, carbon paste, and carbon fibers have gained popularity. Mercury, gold, bismuth, and other metals can be deposited as thin metal films on carbon and serves as thin metal film electrodes (TMFE) with excellent analytical advantages in trace metal analysis. The choice of working electrode is determined by the redox... 

It is seen by examination of Table 1.11(b) that a wide variety of techniques have been employed including spectrophotometry (four determinants), combustion and wet digestion methods and inductively coupled plasma atomic emission spectrometry (three determinants each), atomic absorption spectrometry, potentiometric methods, molecular absorption spectrometry and gas chromatography (two determinants each), and flow-injection analysis and neutron activation analysis (one determinant each). Between them these techniques are capable of determining boron, halogens, total and particulate carbon, nitrogen, phosphorus, sulphur, silicon, selenium, arsenic antimony and bismuth in soils. 

The ylides and imides are present as monomers, and the bismuth center adopts a distorted tetrahedral geometry. In contrast, the structural properties of the bismuth oxides vary widely depending on the aryl ligands attached to the bismuth center the oxides exist as hydrates, dimers, or polymers in solution and in the solid state. X-ray structural analysis of an oxide dimer revealed that the bismuth center has a distorted, trigonal bipyramidal geometry with the two oxygen atoms at the apical and equatorial positions [47, 48]. 

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