摘要:

A pontentiometric flow system based on a sparingly soluble mixture of lead laurate and lauric acid as the responsive element and a glass electrode as the primary sensor is reported. The response of the system to copper, cadmium, zinc and aluminium is also presented.Although the system is relatively unselective, it has the advantage over commercial (Ag2S/PbS-based) lead ion-selective electrodes of reversibility of response to copper and cadmium.

ISSN:0003-2719    

DOI:10.1080/00032718508066188

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

The polarographic reduction of methylmercury in aqueous medium takes place in two steps, each of which involves the transfer of a single electron. The first reduction step proceeds reversibly both in direct current and in sinusoidal alternating current. Since the polarograms corresponding to this step are well defined, they can be successfully used to determine methylmercuric compounds by phase-sensitive sinusoidal a.c. polarography, in the concentration range 1 × 10−7−1 × 10−4mole.dm.−3

ISSN:0003-2719    

DOI:10.1080/00032718508066189

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

Experimental data are given on the influence of the number and the position of the amino groups on the electrochemical reduction potentials of aminoanthraquinones.

ISSN:0003-2719    

DOI:10.1080/00032718508066190

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

The electrooxidation of adsorbed glycerol species on platinized platinum electrodes in 1 N H2SO4was studied by cyclic voltammetry and the potential step method. The main conclusions are: the electrooxidation of glycerol at potentials lower than 1.2 V (vs, RHE) is a complex reaction in which more than one adsorbed intermediates are probably involved. The adsorbed intermediates exhibit ageing effects, at higher potentials a chemical interaction between glycerol and adsorbed oxygen occurs and the overall process is controlled by mass transfer.

ISSN:0003-2719    

DOI:10.1080/00032718508066191

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

Ion-selective electrode determinations of potassium and calcium have been carried out on skim milk powder and the results compared with data obtained by flame emission spectroscopy for potassium and by atomic absorption spectroscopy for calcium. The data indicate that ion-selective electrodes can be used as an alternative to spectroscopic methods for determining these metals by using a dry-ashing pretreatment procedure. Acid digestion pretreatment is not recommended because of the ensuing high ionic strength and possible interferences. Sodium and magnesium contents obtained by spectroscopy are also quoted for interest. The various percentage metal contents are: potassium: 1.96 ± 0.155 (ISE direct) 1.81 ± 0.144 (ISE Gran) and 1.82 ± 0.076 (flame emission), sodium: 0.511 ± 0.017 (flame emission), calcium: 1.37 ± 0.095 (ISE direct), 1.36 + 0.079 (ISE Gran) and 1.41 ± 0.082 (flame aas), and magnesium 0.119 ± 0.003 (flame aas).

ISSN:0003-2719    

DOI:10.1080/00032718508066192

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

In the proposed method, chloride is oxidized to chlorine gas and the transient absorbance signal of the latter is measured using atomic absorption instrumentation. Instead of the flame, a flow-through absorption cell is used. The method is rapid and direct. The detection limit is 14 μg/mL Cl.

ISSN:0003-2719    

DOI:10.1080/00032718508066193

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

A simple near-IR transmission spectroscopy method for the determination of percent carbon coverage in trimethylsilylated silicas has been developed. The alkylated silica is slurried in carbon tetrachloride, a solvent with a similar refractive index to silica, to reduce light scattering. Percent carbon is then determined by measuring either the peak height or peak area ratio of the peak at 1180 nm (due to the second overtone of the C-H stretch) to the peak at 1385 nm (due to the overtone of the SiO-H stretch). Comparison with results from elemental analysis permits construction of a correlation curve that can then be used to determine % carbon in unknown samples.

ISSN:0003-2719    

DOI:10.1080/00032718508066194

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

A method is developed for the spectrofluorimetric determination of 1–80 ng.ml−1of gallium with pyrocatechol-1-aldehyde 2-benzothiazolylhydrazone, in a 50% (v/v) DMSO-Water medium at apparent pH 4.0 (monochloracetic/monochloracetate buffer). Λex= 400nm, Λem= 504 nm (corrected). Interferences have been evaluated and the method applied to the determination of gallium in human urine and blood serum samples.

ISSN:0003-2719    

DOI:10.1080/00032718508066195

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

Radicals induced by gamma irradiation of alpha-D-glucose, 1-0-methyl-alpha-D-glucose and maltose, in the solid state, have been studied by the spin-trapping method. High performance liquid chromatography of sugar-nitroxide solutions, combined with electron spin resonance analysis, revealed nine, eight and twelve discernible radical species, the majority of them being indiscernible by the direct spin-trapping method. Tentative correlations and assignments of chemical structures are discussed.

ISSN:0003-2719    

DOI:10.1080/00032718508066196

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

This paper describes the method for the concentration of Cu2+by liquid-liquid extraction using Lix 64N solutions in kerosene, followed by back extraction chromatography.

ISSN:0003-2719    

DOI:10.1080/00032718508066197

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor