摘要:

Extensive high resolution NMR measurements, both in the solid-state and in solution, of starch are reported. Starch samples were in the form of wheat starch and soluble starch from potato. Both wheat starch and whole wheat grain samples were run in the CPMAS experiments. Apart from the normal13C spectra, 50.29 MHz for the CPMAS and 67.89 MHz for the solution, we also measured proton T1and T1pand13C T1in the CPMAS experiments.

ISSN:0038-7010    

DOI:10.1080/00387018708081594

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Procedures have been developed for the flame atomic absorption spectrometric determination of rhodium in a polymer used in the rubber industry. Rhodium can be determined directly using a solid sample or in chlorobenzene solution. A modified graphite furnace is used to volatilize the sample, after ashing, into the flame atomizer. Thus a large reduction in background signal is obtained compared to conventional furnace atomic absorption spectrometry. Larger sample weights(up to 10 mg) can be employed, cutting down on problem of sample inhomogeneity. The carrier gas used is an argon/air mixture. This combined with the use of a magnesism chloride matrix modifier, maximized the obtainable signal. Direct solid sample results showed precision in the 10 to 20% range. This relatively poor precision could he traced mainly to our lack of a microbalance.

ISSN:0038-7010    

DOI:10.1080/00387018708081595

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The Keating force field of pyramidal XY3molecules is defined in analogy with valence and central force fields. Its usefulness in comparison with valence and central force fields is discussed. Different “exact” force fields are also investigated and expressed in terms of valence, central and Keating coordinates. This approach indicates the superiority of the coordinate system which gives the smallest magnitude of the interaction force constant. The conclusions are not unequivocal, but they go in favour of the Keating coordinates when the most reliable calculations are considered.

ISSN:0038-7010    

DOI:10.1080/00387018708081596

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The 60 MHz1H NMR spectra of racemic meparfynol,1, have been studied in CDCl3solution at 28° with the achiral shift reagentt tris(6,6,7,7,8,8,8-hepta-fluoro-2,2-dimethyl-3,5-octanedionato) europium (III),2, and the chiral reagent, tris[3-(heptafluoropropyl-hydroxymethylene)-d-camphorat01 europium(III),3. With3, observable enantiomeric shift differences for the 3-methyl should make possible direct optical purity determinations. Additions of increments of (6,6,7,7,8,8,8-heptafluoro-2,2-dimenthyl-3,5-octane-dionato)silver(I)4, to a CDCl3solution of1and3resulted in changes in Δδ magnitudes and in some line intensities that are discussed in terms of interactions with the ethynyl and hydroxyl groups.

ISSN:0038-7010    

DOI:10.1080/00387018708081597

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Dibutyltin and tributyltin compounds in artificial sea water were determined at sub-ppb levels. These compounds are separated from matrix elements in aqueous solutions by a simultaneous hydride generation dichloromethane extraction. After dichloromethane is vaporized, the residue is dissolved in hexane and is directly injected into the treated graphite tube and the signal is measured by a Zeeman atomic absorption spectrometer.

ISSN:0038-7010    

DOI:10.1080/00387018708081598

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

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

ISSN:0038-7010    

DOI:10.1080/00387018708081593

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor