摘要:

A liquid membrane ion-selective module based on a solvent polymeric membrane is combined with an external reference electrode into one assembly. This combination electrode has an extremely small drift of about 30 μV per 9 hours and < 10 mV per year when uncharged carriers are used as ion selective components. The design makes an easy replacement of the ion-selective modules possible.

ISSN:0003-2719    

DOI:10.1080/00032717908082522

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

A stationary-solution voltammetry cell using a unique geometry for electrode placement is described. Semimicro working and auxiliary electrodes are contained in a small sample compartment, which is isolated from a larger reference compartment by a porous glass junction. The very simple design permits cyclic voltammetry to be conveniently performed with 25–50 μL volumes containing small amounts (typ. 5 μg) of rare synthetic or isolated metabolites.

ISSN:0003-2719    

DOI:10.1080/00032717908082523

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

A method is described for the determination of traces of arsenic in industrial ZnSO4solutions for electrolysis by cathodic stripping voltammetry. The limit of detection is of the order of 1 ppb.

ISSN:0003-2719    

DOI:10.1080/00032717908082524

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

We have determined the electrocapillary curves of the mercury electrode with a mixture of hydrogen fluoride and water contaning 40% (by weight) of HF, using the mercury electrode drop time formation technique. The addition of KCl at concentrations from 0.01 to 0.5 M provokes a displacement of the electrocapillary curves showing a possible specific adsorption of HCl at the electrode.

ISSN:0003-2719    

DOI:10.1080/00032717908082525

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

A mixture of 1 percent aqueous solution of K2S2O8and 0.01 M aq. AgNO3in the ratio of (5:1) has been found to be a very sensitive spray reagent for the detection of sulphonamides in ng range on silica gel plates impregnated with pyridinium tungstoarsenate ion exchanger. The suitable developing solvent systems for these separations found are benzene-methyl alcohol-ethyl acetate- acetic acid-water (40:10:10:5:2) and benzene-ethyl acetate (20:30).

ISSN:0003-2719    

DOI:10.1080/00032717908082526

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Zirconium forms stable, insoluble, chelate compounds with many organic alpha-hydroxyacids (substituted glycolic acids) and a number of them have been investigated for the gravimetric determination of zirconium. Four new reagents were studied: hexahydromandelic acid, atrolactic acid, p-phenylene diglycolic acid and 2-hydroxy-4-phenyl-3-buteonic acid. Quantitative precipitation of zirconium was achived with all the above acids but most precipitates are of indefinite composition and must be ignited to the oxide for weighing. These studies lead to a better understanding of the nature of alpha-hydroxyacid complexes of zirconium.

ISSN:0003-2719    

DOI:10.1080/00032717908082527

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

A capillary solid-state spot test technique has been developed for the assay of p-dimethylaminocinnamaldehyde. This technique has several distinct advantages over normal methods.

ISSN:0003-2719    

DOI:10.1080/00032717908082528

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The sample is prepared by grinding, blending, and ashing. Dissolution of the ash is accomplished by a multistep acid digestion. The sample solution is analyzed by atomic absorption for eleven elements. A spectrophotometric analysis is used to determine titanium. The relative standard deviation (RSD) for all twelve elements ranged from 2.44 to 122%. Aluminum, copper, and lead analysis produced the high RSD values.

ISSN:0003-2719    

DOI:10.1080/00032717908082529

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

An ion chromatographic procedure is described for the analysis of arsenic as the oxo anion. The procedure involves oxidations of the arsenic to arsenate in an aqueous solution and injection onto an anion separator column, Comparison is made with a standard wet chemical procedure, and data is presented on reproducibility. In addition, there is a brief discussion of the applicability of this method to the determination of other oxo anions.

ISSN:0003-2719    

DOI:10.1080/00032717908082530

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Adequately separated signals in the nuclear megnetic resonance spectra of mixtures of cyclocitrals were assigned to the individual components. This assignment allowed direct integration of the signals of interst and calculation of the percentages of α-cyclocitral, β-cyclocitral,para-cymene, and 1-acetyl-4, 4-dimethyl-1-cyclohexene. The rapidity and nondestructive nature of the nuclear magnetic resonance analysis are superior to the fractional crystallization of the semi-carbazones and gas chromatography techniques previously utilized.

ISSN:0003-2719    

DOI:10.1080/00032717908082531

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor