摘要:

An investigation of an Ag/Ag+reference electrode in dimethylformamide solution is reported. Simple preparation, fast response and high exchange current density characterize this reference electrode. The stability of the electrode with time and its temperature coefficient were also studied.

ISSN:0003-2719    

DOI:10.1080/00032718308065250

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

1,4,7,10-Tetraoxacyclododecane (12-crown-4) (I) and its lithium complex (II) are used as neutral carriers for lithium ion in polyvinylchloride membrane ion selective electrodes. The lithium response varies with concentration, being near Mernstian at low (10−5-10−4M) concentrations and sub-Nernstian (24-28 aV) at higher concentrations (10−3M). The selectivity coefficients KLiPotMfor II are: Na+(0.12), K+(0.66), Cs+(0.15), Mg2+(1.6 × 10−4), Ca2+(3.1 × 10−4), Ba2+(9.5 × 10−7), NH+4(9.0 × 10−2), H+(2.2).

ISSN:0003-2719    

DOI:10.1080/00032718308065251

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

A highly sensitive and specific detection method has been developed for iron with a limit of detection ∼ 0.0001 mg per 0.02 ml on the beads of siroomium(IV) arsemophosphate cation exchanger, utilizing its adserptie-iem-exchange properties and the complex forming ability of 1, 10-phenanthroline. A mechanism has also been proposed tentatively on the basis of some experimental observations and theoretical considerations.

ISSN:0003-2719    

DOI:10.1080/00032718308065252

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

An open-tubular micro capillary column was prepared by coating the inner wall of a pyrex tube (50 μm i.d.) with polyamide. Chromatographic behaviors of trace amounts of various phenolic compounds, benzoic acid derivatives and aromatic amino and nitro compounds, were examined on this column.

ISSN:0003-2719    

DOI:10.1080/00032718308065253

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

A suitable chromophore- and fluorophore- forming reagent for the detection of alkyl halide water contaminants is β-naphtol. The ether derivatives are separated from each other and excess β-naphthol reagent by reverse, phase HPLC and are detected by ultraviolet absorption or fluorescence. A method for the determination of alkyl halides is presented. The method is applicable to concentration levels in the ppm range for UV detection and in the ppb concentration range using fluorescence detection.

ISSN:0003-2719    

DOI:10.1080/00032718308065254

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

A spark source mass spectrometric system has been developed for trace levels of oxygen and carbon in gallium arsenide using liquid helium cryopumping of the source chamber. Following bake-out, a collector positioned inside the source chamber is cooled using a controlled flow of liquid helium. Residual back-ground gases are more effectively removed than with liquid nitrogen and detectabilities of 0.02 ppma for oxygen and 0.05 ppma for carbon have been obtained. Routine analyses are carried out with a moderate consumption of liquid helium.

ISSN:0003-2719    

DOI:10.1080/00032718308065255

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

The new method, proposed in a preceeding paper for the determination of elements in plant material by flame atomic absorption spectroscopy (FAAS) with liquid sampling of carbonaceous slurry, was tested on other kinds of organic material such as vegetable foods and feeds. Results are reported for the determination of calcium, magnesium, potassium, iron, manganese, zinc and copper in these materials. Also, the analytical results relative to the determination of cadmium by graphite-tube furnace atomic absorption spectroscopy (GTFAAS) for two matrices are given. In all cases accuracy and precision of the analytical procedure were ascertained.

ISSN:0003-2719    

DOI:10.1080/00032718308065256

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

In this paper a spectrophotometric method for the Mn(II) determination is proposed. This method is based on the extraction in toluenic Adogen 464 solution of the complex origined between Mn(II) and isophtaldihydroxamic acid. The method permits determination of 50-100 γ of Mn (II). The error and the molar absorptivity are values of 2.0% and 8.500 1. mol.−1.cm−1respectively. The interference levels caused by foreign ions are established. Also the standard line by extraction with ethylacetate Adogen 464 solution was studied.

ISSN:0003-2719    

DOI:10.1080/00032718308065257

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

The quantitative determination of formaldehyde in air using the fluorimetric acetylacetone method is described. Known concentrations of formaldehyde were generated and collected in water using abosorbers. The sampling rate was 0.5 1/min, and the sampling volumes varied from 2 to 20 1, depending on the concentration level. Under these conditions the entire sampling and the analytical method were evaluated over a range of 0.2–1.7 mg formaldehyde per m3of air.

ISSN:0003-2719    

DOI:10.1080/00032718308065258

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

Substoichiometric radioisotope dilution analysis has been applied to the determination of sulfur in coal. The experimental procedure involved the combustion of coal samples labelled with35S as sodium sulfate in a flowing oxýgen stream, collection of the combustion gases in hydrogen peroxide and substoíchiometric precipitation of barium sulfate. Samples of 0.2–10.0% sulfur were accurately determined with ±2% RSD by measuring the activity of the precipitates thus obtained and with comparison to standard samples carried through the same procedure. Analysis times of 15 minutes per sample were typical.

ISSN:0003-2719    

DOI:10.1080/00032718308065259

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor