摘要:

A simple and an inexpensive procedure for the construction of the reference electrodes and of the conversion of ion-selective electrodes to the “combination” types is described. It allows the manipulation of the reference electrode filling solution according to the needs of a particular measurement. The electrodes have good reproducibility and stable inter-comparison potentials of ± 0.2 mV. The performance characteristics of these electrodes are satisfactory for potentiometric measurements.

ISSN:0003-2719    

DOI:10.1080/00032717508059049

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Copper, cadmium, and zinc in vegetables growing near an industrial complex in Engis (Meuse Valley), Belgium, were determined by oscillopolarography over a three-year period. The influence of large concentrations of these metals on plants and food toxicology are discussed.

ISSN:0003-2719    

DOI:10.1080/00032717508059050

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

In order to compare the polarographic behaviour ofcisandtransaliphatic azoxy compounds, synthesis and polarographic study ofcisandtransazoxycyclohexanes are performed. Thecisform is a new compound obtained by photoisomerisation of thetranscompound. In acid medium the polarographic reduction process is the same for both forms: hydrazocyclohexane is the final reduction product. In alkaline medium thetransazoxy compound is electroinactive and thecisazoxy compound is reducible and leads to a mixture oftransazocyclohexane and hydrazocyclohexane.

ISSN:0003-2719    

DOI:10.1080/00032717508059051

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Reverse phase partition chromatography on a 10 micron silica-bonded octadecyl hydrocarbon substrate is applied to the separation of neutral tetradentate chelates of copper (II), nickel (II) and palladium (II) with a range of non-fluorinated and fluorinated beta-ketoamine and salicylaldimine ligands. Variation of retention and resolution with respect to changes in ligand structure and metal chelated is investigated using acetonitrile, methanol and water solvent systems. Detection limits (254 nm) and linearity ranges of response are indicated.

ISSN:0003-2719    

DOI:10.1080/00032717508059052

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

The propellant gases (Freons) used in aerosol spray cans can diffuse into the earth's upper atmosphere where they can react with the unfiltered ultraviolet radiation from the sun to reduce the earth's protective ozone layer. These Freons have been identified commonly by gas chromatography. Mass spectrometer data confirm other reports on the widespread concentrations of the Freons in the troposphere and demonstrate the presence of Freon 113 which has not been previously identified.

ISSN:0003-2719    

DOI:10.1080/00032717508059053

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Satisfactory recovery studies of thirteen trace elements, Na, K, Ca, Mg, Zn, Cu, Fe, Mn, Co, Pb, Li, Cd and Cr in human scalpal hair was obtained. There is little or no interference in the analysis of these elements in hair matrix by atomic absorption spectrophotometry using the wet nitric and perchloric acid digestion method. Methods to remove surface contamination in hair were also discussed.

ISSN:0003-2719    

DOI:10.1080/00032717508059054

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

By the combined use of a decomposition vessel, chelating resin, and atomic absorption spectrometry, a simple method for the determination of copper in silicate rocks was devised. A sample was digested overnight at room temperature with small amounts of hydrofluoric acid and aqua regia in the Teflon vessel having a sealing stopper. In the presence of citrate, only the supernatant of the digested sample solution was passed through a small column of the chelating resin, Dowex A-1, at pH 4. After elution with nitric acid, copper was determined by ordinary atomic absorption spectrometry. The recovery, reproducibility, and accuracy of the method were quite satisfactory. The analytical results obtained for the standard rocks agreed well with reported results.

ISSN:0003-2719    

DOI:10.1080/00032717508059055

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

The surfaces of both normal and fluoride treated human dental enamel were examined with x-ray photoelectron spectroscopy (ESCA). Using argon-ion etching to remove thin layers of enamel, subsurface layers were also analyzed. The resulting composition-depth profile showed that stannous fluoride produced a subsurface layer containing both tin and fluoride whereas fluorine was absent from the surface layer. Acid fluoride treatments, however, converted the surface to calcium fluoride which steadily decreased in concentration with depth.

ISSN:0003-2719    

DOI:10.1080/00032717508059056

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Since air quality in industrial atmospheres is important for personal comfort and safety, tracer experiments using sulfur hexa-fluoride (SF6) are commonly used to monitor air distributions and flow patterns.

ISSN:0003-2719    

DOI:10.1080/00032717508059057

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Atomic absorption spectroscopy has been used to determine the concentration of lead in gasoline. The method employs the use of iodine to “level” the variation in response of different lead alkyls. It has been reported that this method is useless when applied to real gasolines, possibly because of the interference of iodine with olefins in the gasoline. The work performed here shows that olefins do not interfere with the lead analysis even when the concentration of olefins is 254 times that of iodine in the test gasoline.

ISSN:0003-2719    

DOI:10.1080/00032717508059058

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor