摘要:

AbstractThe theory of gradient elution under hydrostatic equilibrium is developed for the case where only one reservoir and one mixing chamber are used and where both solvents have equal densities. Given the shapes of the two vessels, effluent concentration curve equations are deduced for different mixing chamber‐reservoir combinations. On the other hand, given the equation for the effluent concentration curve, the reservoir cross‐sectional area, as a function of height, can be deduced when the mixing chamber has a constant cross‐section. The varying cross‐section of the reservoir is accomplished by inserting thin discs of different areas on top of one another inside a regular vessel of constant cross‐section.Except for complicated gradients, a given gradient can be accomplished using a reservoir with a cross‐sectional area which varies linearly with height. In the case of complex gradients, a reservoir having two or more linear segments becomes necessary. A numerical method is given for the calculation of the continuously varying reservoir cross‐section for the exact duplication of a g

ISSN:0935-6304    

DOI:10.1002/jhrc.1240020402

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractThe expression for the resolution function, R, in terms of operating parameters for open tubular columns has been extended to include inlet contributions to the peak variance. Subsequent optimization has revealed the existence of optima in the column radius, the stationary phase thickness and the diffusion coefficient ratio in the stationary and mobile phases‐in addition to the well‐known optimum in the flow velocity. This implies that R at optimum becomes R=f(K)L0.6Vi−0.2, i.e. a function only of the column length, L, the inlet volume, Vi, and the concentration distribution coefficient, K. For given K, L and Viall other parameters such as retention time and pressure drop can thus be directly computed. The information is finally consolidated in the form of contour diagrams. The text itself is cast in the form of a science fa

ISSN:0935-6304    

DOI:10.1002/jhrc.1240020403

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractA capsule‐insertion system tailored to the needs of capillary gas chromatography is described. It provides the basis for a truly quantitative and improved qualitative approach to open tubular capillary GLC. The advantages of the system lie in its simplicity of handling and in the possibility of using relatively low injection temperatures, thus reducing the risks to thermally unstable samples.The observed high efficiencies characterizing this capillary GLC capsule technique allow full advantage to be taken of the operating capacity of the superior capillary columns to give a performance competitive with the best known split‐injection syst

ISSN:0935-6304    

DOI:10.1002/jhrc.1240020404

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

ISSN:0935-6304    

DOI:10.1002/jhrc.1240020405

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

ISSN:0935-6304    

DOI:10.1002/jhrc.1240020406

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

ISSN:0935-6304    

DOI:10.1002/jhrc.1240020407

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractA new method for the determination of triphenyltin hydroxide using capillary column gas chromatography with a tin‐selective flame photometric detector has been developed. Triphenyltin hydroxide and its potential metabolites are converted to methyl derivatives and separated on glass capillary columns coated with OV‐101. Derivatization of triphenyltin hydroxide, triphenyltin chloride, diphenyltin dichloride, phenyltin trichloride, and bis‐triphenyltin oxide is nearly quantitative with a minimum of redistribution products. The selectivity of the flame photometric detector is cearly demonstrated by the comparison of chromatographic profiles obtained from using both the flame photometric and flame ionization detectors.The use of this chromatographic system in the analysis of triphenyltin hydroxide in a fortified water sample demonstrates the potential use of this system in organotin residue chem

ISSN:0935-6304    

DOI:10.1002/jhrc.1240020408

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

ISSN:0935-6304    

DOI:10.1002/jhrc.1240020409

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

ISSN:0935-6304    

DOI:10.1002/jhrc.1240020410

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractA method is described for the qualitative and quantitative determination of configurational isomers of astaxanthin. It is based on the esterification of astaxanthin with (—)‐camphanic acid chloride and analysis of the corresponding diesters by H

ISSN:0935-6304    

DOI:10.1002/jhrc.1240020411

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY