摘要:

Reference electrodes limiting interfering effects of conventional reference electrodes on the measurement involving ion-selective electrodes have been developed. They are constructed of a plastic body with porous plug or sleeve junction. Solid state, low impedance, ion-selective electrodes (cupric, cadmium, fluoride) in the equilibrium of corresponding ion solution are used as the half-cells. The absence of interfering ions in the electrolyte allows the determination of the ion of interest at extremely low levels without interference. The electrodes have good reproducibility and stable intercomparison potentials of ± 0.2 mV. The performance of the electrodes has been tested for the measurement of sub-ppm halide levels. Data on stability, reproducibility, effects of temperature, ionic strengthand pH is presented and compared to that of conventional reference electrodes.

ISSN:0003-2719    

DOI:10.1080/00032717908067914

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Eleven trace impurities are determined in high purity cadmium by employing d. c. arc emission spectrographic technique. Cadmium ie converted t o its oxide and ground with high purity conducting graphite powder which acts as a buffer. Forty milligrammes of the above mixture is excited in a d. c. arc set at 12 amperes. The spectra of the sample and synthetic standards are photographed on a Jarrell-Ash 3.4 meter Ebert plane grating spectrograph in the region 2175 - 3425 A using a 1200 lines per mm grating in the first order. The detection limits obtained range from 1 to 10 ppm for different elements. The average coefficient of variation ranges from 8.0 to 15.7% for the impurities.

ISSN:0003-2719    

DOI:10.1080/00032717908067915

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

A new spectrophotometry determination of Os(IV) has been developed, based on the formation of the [OsCl6]2−- 1-carb-ethoxypentadecyltrimethylammonium cation ion-associate extract-able into chloroform. The measurement is carried out at 340 or 376 nm. It is possible to determine 1.5 to 18.6 μg Os in 1 ml of the chloroform phase.

ISSN:0003-2719    

DOI:10.1080/00032717908067916

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The cesium salt of R, R-(-)-trans-l, 2-cyclohexane-diaminetetraacetatocobaltate(III), Δ-(+)546-Cs[Co(R, R(-)-CDTA)], Δ-Cs[Co(R, R(-)CDTA)]), provides a compound which can be used for calibration of circular dichrometers in the visible region. Δ-Cs[Co(R, R(-)CDTA)] has three major circular dichroism (CD) maxima at 593 nm, 527 nm, and 240 nm. The molecular ellipticities, [], at 593 nm, 527 nm, and 240 nm are -4490 ± 40, 5720 ± 40, and -47, 900 ± 300 deg cm2dmol−1, respectively. The CD maxima in terms of Δε at 593, 527, and 240 nm are -1.36 ± 0.01, 1.73 ± 0.01, and -14.5 ± 0.1 l cm−1mol−1, respectively. Optical rotatory dispersion (ORD) and ultraviolet-visible absorption data has also been obtained for this compound.

ISSN:0003-2719    

DOI:10.1080/00032717908067917

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Cyclohexane is the solvent of choice for the extraction of n-alkanes from environmental matrices. This solvent contains traces of bicyclohexyl. This impurity does not interfere with analyses at the ppm level, but is a potential problem at the ppb* level. Erroneous concentrations of n-tridecane could be obtained using conventional packed gas chromatographic columns. However, this problem is obviated by using capillary columns or combined gas chromatography - mass spectrometry.

ISSN:0003-2719    

DOI:10.1080/00032717908067918

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The polynuclear aromatic compounds (PNA): anthracene, napthalene, phenanthrene, pyrene, pyrenecarboxaldehyde, benzo (a) pyrene, benzo (e) pyrene, perylene and fluorene can be chromatographed on polyamide TLC sheets using an aqueous micellar solution cf sodium dodecylsulfate (SDS) as the mobile phase. Reversed micellar solutions (of sodium dioctylsulfosuccinate) were used in a reverse phase chromatographic separation of amino acids. Some amino acids tended to streak slightly rather than move as discrete spots. Conditions could be adjusted, however, so that most of the amino acids and all PNA's would move as spots.

ISSN:0003-2719    

DOI:10.1080/00032717908067919

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

We have extended our earlier work on alkylation of secondary amino compounds with dimethylformamide diethyl acetal to other alkyl acetals, such as dimethyl and dipropyl acetal. All the alkylating DMT-dialkyl acetal reagents tested gave only N-ethyl derivatives of the secondary amines. The reagent purity was tested by preparing the esters of carboxylic acids, where the appropriate alkyl (methyl or propyl) ester is obtained. It is concluded that all dimethylformamide dialkyl acetals yield a single N-ethyl derivative of secondary amine. The reaction mechanism is not understood.

ISSN:0003-2719    

DOI:10.1080/00032717908067920

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The solid monoxime of 2, 3-butanedione is a more convenient material than liquid dione for the homogenous generation of DMG. 2, 3-butanedione dioxime. Determinations of Ni in steels and in pure Ni(II) solutions have shown the optimum pH and order of adding reagents. Gravimetric and/or an EDTA titrimetric finish are possible for a method of reliability within ± 0.2 mg of Ni in 50–150 mg Ni. The solid has the same character and filterability as that from the 1960 dione method of Salesin and Gordon1.

ISSN:0003-2719    

DOI:10.1080/00032717908067921

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:0003-2719    

DOI:10.1080/00032717908067913

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor