摘要:

The paper describes the conditions of polarographic reduction of trinitrotriphenylamine. The reduction occurs in 2 steps of similar height (one for trihydroxylaminotriphenyl-amine and the other for triaminotriphenylamine). The method allows the polarographic determination of trinitrotriphenylamine between 0.1–0.5 mg/ml. In the presence of silver ions, the polarographic steps are shifted to more negative potentials, which indicates formation of a compound of silver with triaminotriphenylamine.

ISSN:0003-2719    

DOI:10.1080/00032718108059818

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Two methods for oxalate determination with a fluorideselective electrode are proposed. For oxalate amounts higher than 0.2 mmol, the joint precipitation of oxalate and standard fluoride with lanthanum(III) can be used. For smaller oxalate amounts, the precipitation of oxalate with excess of lanthanum(III) followed by back-titration with fluoride, is suitable. The end-points are located using the second derivative procedure and by means of the Gran method, respectively.

ISSN:0003-2719    

DOI:10.1080/00032718108059819

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

The electrochemical reduction of Fe(III) in aqueous ethylene glycol solutions was studied by chronopotentio-metry and cyclic voltammetry in the temperature range of 25.0–45.0 °C, in 1.0 M HCl04as supporting electrolyte. It is shown that the reduction of Fe(III) ion proceeds via a revesible charge transfer. Limiting chronopotentiometric transition times and limiting diffusion layer thickness were determined using unshielded horizontal disk and vertical wire working electrodes. Values of the formal electrode potential and of solvo-dynamic radii for Fe(IH) are given in the studied temperature range.

ISSN:0003-2719    

DOI:10.1080/00032718108059820

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Cadmium ion reacts with cadion and 1, 10-phenanthroline to form a 1:1:2 orange-red ternary complex in 0.5N sodium hydroxide medium. The complex is extracted by chloroform and has a molar absorptivity of 9.2 × 104l. mole−1. cm−1at 490 nm. A method is developed for the determination of cadmium in electroplating waste water.

ISSN:0003-2719    

DOI:10.1080/00032718108059821

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

A spectrofluorometric study of the reaction 1, 8-Didydroxv anthraquinone-Li(I) was made in ethanol and acetone media. A new method for the spectrofluorometric determination of Li(I) is proposed, with a range between 100 and 700 ppb of Li(I) in ethanolic medium and between 50 and 450 ppb in acetone medium. The methods show errors of 2.00 and 2.90 % respectively.

ISSN:0003-2719    

DOI:10.1080/00032718108059822

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Texts on fluorescence spectroscopy state that the observed intensity of fluorescence is inversely proportional to the square of the refractive index of the solvent. This statement is evaluated for various arrangements of slits-To test the effect of refractive index, a concentric cell was fashioned and the fluorescence signals recorded for emission which passed through solvents with refractive indices from 3.33 to 1.63. There was no significant effect of refractive index on the signals. From these experimental results, and also from geometrical considerations, it is concluded that the n2correction factor would be erroneous for most fluorometers.

ISSN:0003-2719    

DOI:10.1080/00032718108059823

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

A method is described for extracting representative uranium and plutonium samples from highly radioactive solutions for isotopic mass spectrometric analysis. Anion resin beads in the nitrate form are used to effect separation from fission products and other actinides. Conditions required to achieve separation are proper adjustment of the uranium and nitric acid concentrations. Once uranium and plutonium are adsorbed, each bead serves as a sample for mass spectrometric analysis, with plutonium and uranium being run sequentially from the same bead. Quantitative determination of the two elements is effected through the technique of isotopic dilution.

ISSN:0003-2719    

DOI:10.1080/00032718108059824

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

A study was performed to confirm suspected artifactual formation of acetone derivatives during the Soxhlet extraction of soil samples with acetone. The conditions employed simulated very closely those normally employed for the extraction of soils for neutral and moderately polar organic compounds such as pesticides. A series of acidic, neutral, and basic organic-free soils were extracted with hexane/acetone solvent mixture and the extracts concentrated in a Kuderna-Danish apparatus. The extracts were analyzed by capillary column gas chromatographic mass spectrometry. In nearly all cases, simple dimeric products such as diacetonecohol and mesityl oxide were formed in varying amounts. The acidified and basic soils yielded complex mixtures of dimers, trimers, tetramers and other complex homologs. Some of the more common substances found include phorone, mesitylene and isophorone. The latter substance is listed as an EPA priority pollutant.

ISSN:0003-2719    

DOI:10.1080/00032718108059825

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

After being precipitated as silver mercaptides, mercaptans were converted into their pentafluorobenzyl derivatives in high yields by reaction with sodium sulfide and then with pentafluorobenzyl bromide. The derivatives were analyzed down to sub-ppm levels by gas chromatography with a flame ionization detector. It is possible that the above method is developed for the trace analysis of mercaptans in environmental matrices.

ISSN:0003-2719    

DOI:10.1080/00032718108059826

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

The widely used aerosol collection filters composed of polytetrafluoroethylene (Teflon) present a problem in the extraction of water soluble ions from the collection surface due to the hydrophobic nature of the Teflon. A method is presented for the extraction and analysis of water soluble ions from Teflon aerosol filters which is efficient and sensitive. This method uses a direct application of ethanol to the filter surface to decrease the surface tension of the filter and allow a dilute HC10, solution to contact the collection surface and extract any water soluble ions. This study compares this extraction method with other extraction methods currently being used. The results obtained from the extraction of water soluble ions from the Teflon filters were also compared to the results obtained from quartz filters collected on a colocated high volume sampler. From these studies, it is concluded that the hydrophobic nature of the Teflon filters makes the complete dissolution of water soluble ions exceptionally difficult and that the prewetting of the Teflon filters with ethanol minimizes dissolution and extraction problems.

ISSN:0003-2719    

DOI:10.1080/00032718108059827

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor