摘要:

Various solvents and operating conditions were investigated for paperchromatographic separation of the various esters in the mixture obtained by the reaction P4O10+ 4ROH. Optimum separation was obtained with a propanol-isobutanol-water-ammonia solvent at 10° during 16 hr and perchloric acid-ammonium molybdate developer. These conditions were found to produce complete separation in all investigated mixtures, independently of the nature of the organic chain in the esters. Preparative separation of the various products was obtained by column chromatography, using the same solvent as in paper chromatography on a cellulose-packed column.

ISSN:0037-2366    

DOI:10.1080/01496396808052203

出版商:Taylor & Francis Group    

年代:1968

数据来源: Taylor

摘要:

Ferric nitrate solutions with different degrees of hydrolysis were investigated on polydextran gels having various exclusion limits. Typically chromatograms exhibited two well-resolved peaks, one at the void volume and the other at the total liquid volume of the gel. The respective peaks corresponded to higher and lower molecular weight fractions of the iron in the injected sample. Similar behavior was observed in “negative-peak” investigations where the positions of sample and eluent were reversed. Frontal analysis of the iron solution showed two breakthroughs corresponding to excluded iron moving in the void volume and admitted iron moving near the total liquid volume of the gel. The molecular size distribution of the ferric nitrate samples was studied as a function of OH-Fe ratio by noting changes in the percentage of iron in the respective fractions for gels having known exclusion limits.

ISSN:0037-2366    

DOI:10.1080/01496396808052204

出版商:Taylor & Francis Group    

年代:1968

数据来源: Taylor

摘要:

The decrease in the plate height with increasing Reynolds number, predicted by theory, has been verified for gas chromatography in open tubular columns. It has been shown that this decrease is most pronounced when the mass distribution coefficientk= 0 and considerably lessened fork> 0. The Golay equation has been found to break down at relatively low flow velocities, viz., Re ∼ 200.

ISSN:0037-2366    

DOI:10.1080/01496396808052205

出版商:Taylor & Francis Group    

年代:1968

数据来源: Taylor

摘要:

The plate-height behavior of open tubular columns, for both gases and liquids, has been studied fundamentally in the turbulent flow region. Appriate analytical expressions have been established on the basis of a purely phenomenological description of turbulent flow dynamics. It has been shown that under these flow conditions, the plate height decreases with increasing Reynolds number and that, most significantly, this decrease is strongly dependent on the mass distribution coefficient.

ISSN:0037-2366    

DOI:10.1080/01496396808052206

出版商:Taylor & Francis Group    

年代:1968

数据来源: Taylor

摘要:

The NO2-, MeO-, Cl-, and Me-phenyl- N-substituted maleimides, N-phenyl-and N-benzylmaleimides, and the chlorosuccinanils were chromatographed on two grades of Silica Gel-G in thin-layer systems using developers of benzene and of mixtures of cyclohexane/ethyl acetate, 2:1 and 3:2. Isomers within any family were not separated, which, contradicts previous results with alumina, while families were resolved. The nonconjugated chlorosuccinanils behaved identically with the hindered and unhindered N-(chloro-phenyl)maleimides. There is no evidence of charge-transfer interaction of delocalized π electrons of planar conjugated maleimides with the silica surface.

ISSN:0037-2366    

DOI:10.1080/01496396808052207

出版商:Taylor & Francis Group    

年代:1968

数据来源: Taylor

摘要:

The results from a study of the removal of gaseous hydrogen chloride by the solid, metal organic complex, chromium oxinate, in a fixed-bed adsorption column is presented in the form of adsorption curves or exit gas concentration histories. These experimental curves are subsequently compared to the solutions of a theoretical mathematical model representing the adsorption process. The model incorporates axial diffusion, as described by G. I. Taylor. A gas phase mass-transfer resistance and a solid-phase adsorption-desorption rate were considered as the mechanisms for the adsorption model. The solutions to the mathematical model were generated by an analog computer.

ISSN:0037-2366    

DOI:10.1080/01496396808052208

出版商:Taylor & Francis Group    

年代:1968

数据来源: Taylor

摘要:

Xanthates, in general, react with metals to give extractable chelates of the type

ISSN:0037-2366    

DOI:10.1080/01496396808052209

出版商:Taylor & Francis Group    

年代:1968

数据来源: Taylor

摘要:

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

ISSN:0037-2366    

DOI:10.1080/01496396808052202

出版商:Taylor & Francis Group    

年代:1968

数据来源: Taylor