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A new reagent for the colorimetric and spectrophotometric determination of phosphorus, arsenic and gurmanium is described. It contains Mo(Vl) amd Mo(V) in the ratio of 3 : 2 in an acid medium, 10N with respect to H2SO4 and 3N with respect to HCl.The absorption spectra, the influence of temperature, time, quantity of reagent and selectivity of the method have been studied. Beer's law is applicable up to 160 μg for P2O5, 220 μg for GeO2 and 230 μg for arsenic, in 50 ml. 相似文献
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K. Srinivasulu D. Purushottam Bh. S. V. Raghava Rao 《Fresenius' Journal of Analytical Chemistry》1958,159(6):406-409
Summary Haematein gives violet colored complexes with thorium and uranium and an orange colored complex with zirconium of the stoichiometric ratios 16, 13, and 11 respectively of the metal and the reagent (Job's method). The reagent and the complexes of thorium, uranium and zirconium show absorption maxima at 520–540 m, 520–540 m 500–520 m respectively. In observations at 540 m in 60 percent aqueous acetone 0.05 mg of thoria (a 12 fold excess of cerite earths has no influence), 0.029 mg U3O8 and 0.025 mg of zirconia may be determined. The spectral characteristics of the complexes indicate a similarity in character in spite of differences in stoichiometric composition. 相似文献
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Acetothioacetanilide, CH(3)CO . CH(2) . CS . NH . C(6)H(5) is found to be a very suitable gravimetric reagent for Pd(II), Pt(II) and Rh(III). The complexes [composition, M(C(10)H(10)NOS)(2); for M = Pd(II) and Pt(II), and M(C(10)H(10)NOS)(3)] are stable and can be weighed after drying at 105-110 degrees . Separation from base metals has been studied, and a structural interpretation made from DTA, TG and infrared data. 相似文献
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N,N'-Diphenyldithiomalonamide, (C6H6. NH. CS)2CH2, is found to be a very suitable gravimetric reagent for nickel(II) and cobalt(II). The complexes, of composition Ni(C15H13N2S2)2 and Co(C15H13N2S2)3, are stable and can be weighed after drying at 110°. Separation from base metals has been studied, and the structural interpretation is supported by DTA, TG, infrared and NMR data. 相似文献
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Calmagite is proposed as a sensitive spectrophotometric reagent for aluminium, (570mmu) = 42000. After aqueous phase reaction at pH 8.6, the metal-reagent complex is extracted into chloroform by formation of an ion-association complex with a quaternary ammonium salt. The method is free from interference by common anions, and cationic interferences may be eliminated by the use of cyanide and EDTA as masking agents. 相似文献
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A reaction of morin with gold(III) in a hydrochloric acid medium has been studied. A redox reaction occurring in the examined
system has been identified. The oxidized form of morin (λmax at 291 nm), being the product of the reaction, has been used as the basis of the spectrophotometric method for the determination
of gold. Gold can be determined in the concentration range of 0.2–12 μg mL−1 (RSD in the range of 0.89–2.38%). The molar absorptivity at 291 nm is equal to 2.02 × 104 L mol−1. cm−1. The developed method was applied to the determination of gold (0.04%) in a cosmetic cream.
Published in Russian in Zhurnal Analiticheskoi Khimii, 2006, Vol. 61, No. 2. pp. 129–133.
The text was submitted by the authors in English. 相似文献
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Zinc acetate can be used for the gravimetric separation of iodide from arscnate, sclenite, phosphite, tclluratc and tclluntc, and rhenium from arsenatc, tcllurate and tcllurite 相似文献
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The merits of the nitroanilines as an alternative to p-rosaniline and fuchsine in the colorimetric determination of sulphur dioxide and sulphites have been investigated. p-Nitroaniline was found to be a stable, well-defined reagent, with which sulphur dioxide can be determined to a high level of precision, the sensitivity being of the same order of magnitude as for p-rosaniline. 相似文献
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Cobalt and nickel ions form yellow complexes with bis-cyclohexanone-oxalyldihydrazone in alkaline solutions. These complexes have maximum absorbances at 292 μg and 330 μg, respectively. The cobalt complex obeys Beer's law from 10-4 to 5.10-3 mg cobalt per ml and the molar extinction coefficient is 6500. The nickel complex obeys Beer's law from 10-4 to 7.10-3 rng nickel per ml and the molar extinction coefficient is 8750. Cobalt and copper or nickel and copper can be determined in presence of each other. 相似文献
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Summary
Chlorophosphonazo-p-Cl, A New Reagent for the Spectrophotometric Determination of Scandium
The synthesis of chlorophosphonazo-p-Cl (CPApC) and a highly sensitive method with CPApC as a new reagent for the spectrophotometric determination of scandium are described. Scandium reacts with CPApC in nitric acid medium at pH 2 to form a 11-type complex which has a maximum absorption at 762 nm. Under the experimental conditions employed, the apparent molar absorptivity is 1.54×105 l·mol–1·cm–1 and the relative standard deviation for 2.0g of scandium is 0.92%. The determination range is 0–6g of scandium in 25 ml of solution by using standard addition-deduction method. Scandium can be determined in the presence of reasonable amounts of rare earths.This work was supported by the Science Fund of the Chinese Academy of Sciences. 相似文献
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Disodium-1,2-dihydroxybenzene-3,5-disulfonate (“Tiron”) gives a bright yellow color with molybdenum(VI). Under optimum conditions (wavelength 390 mμ and pH 6.6-7.5) the sensitivity of this reaction is about 1 part of molybdenum in 10,000,000 parts of solution, when measurements are made on a Beckman Model DU Spectrophotometer using a 1-cm cell.An extensive study on the use of Tiron for the determination of molybdenum in a variety of materials is under way. 相似文献
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Summary Solochrome violet R.S. has proved to be a sensitive colorimetric reagent for the microdetermination of vanadium in the limits of 0.05 to 6 ppm with a sensitive filter photometer or a spectrophotometer, at 580 nm. A large number of cations up to 100 fold the vanadium amount do not interfere with its determination. The present work comprises a comparative study on the behaviour of solochrome violet and Fast Grey, based upon the great similarity in the molecular structure of the two dyes and the influence of the orthonitrophenolic group in the molecule of Fast Grey.Part I: See Z. analyt. Chem. 178, 184 (1960). 相似文献
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Summary The reaction between molybdenum and the sulphonic acid azo dye Solochrome Violet R.S. has proved to be a suitable one for the microdetermination of Mo amounts covering the range of 0.3 to 10 ppm in purely aqueous solutions. The variation of extinction with concentration conforms satisfactorily with Beer's law throughout the whole range. Very many cations and anions do not interfere with such a determination. Ferric iron up to 2 mg per 25 ml is completely masked with ascorbic acid.Part II: Khalifa, H., and S. W. Bishara: Z. analyt. Chem. 178, 345 (1960). 相似文献
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Summary Fast Grey R.A. dye can be used for the colorimetric microdetermination of vanadium in the limits of 0.01 to 1 ppm with a sensitive photometer and 0.05 to 8 ppm with a Beckman instrument, at 560 m. A large number of cations and anions up to 10 fold the vanadium amount do not interfere with its determination. Interference due to ferric iron up to an average of 40 fold or copper up to 2 fold the vanadium concentration is simply eliminated by reduction with ascorbic acid and heating in the case of iron or by the same treatment and the addition of ammonium thiocyanate solution in the case of copper.Part II: See Z. analyt. Chem. 158, 103 (1957). 相似文献
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A flow injection analysis (FIA) procedure for the determination of free chlorine in industrial formulations and water samples is proposed. The manifold is provided with a gas-diffusion unit which permits the removal of interfering species and also the preconcentration of chlorine. The determination of chlorine is performed on the basis of the oxidation by o-dianisidine as a chromogenic reagent to a coloured product which can be monitored at 445 nm. The method (for a preconcentration step of 60 s) is linear over the range 0.04-1.00 mg l(-1) of chlorine, the limit of detection is 0.04 mg l(-1), the reproducibility of the procedure (as RSD of the slope) is 3.7% for a series of four independent calibrations, the precision (as RSD of a series of 30 continuous FIA peaks of 0.56 mg l(-1) of chlorine) is 1.4% and the sample throughput is 40 h(-1). A detailed comparative study of the analytical characteristics of a single mono-channel reverse FIA assembly and the same system but provided with a Fluoropore membrane filter of 0.5 microm pore size was performed to check the advantages of the new approach in terms of sensitivity, selectivity and limit of detection. 相似文献