Comparison of oligo(ethylene oxide)-substituted polysiloxanes with poly(ethylene glycol) as stationary phases for capillary chromatography

Abstract. In situ stationary phase immobilization in principle can be attempted in two different ways: using thermal methods or radical-initiated reactions. Thermal immobilization, in general, is applied for the preparation of columns to be used at ultrahigh temperatures, and radical-initiated immobilization can be applied in most other cases. For polar, narrow-bore. and thick-film columns. low immobilization temperatures are preferred. The reactions involved in the different immobilization methods are described in this review, and the advantages and disadvantages of current immobilization methods are discussed.

Section: Radical-initiated Immobilizationmentioning

confidence: 99%

Current aspects of stationary phase immobilization in open tubular column chromatography

Blomberg

1990

“…The maximum temperature limit of cross-linked and bonded Carbowax-20M is only improved to 270-275°C [3]. Lee et al [4,5] reported ten years ago the synthesis and chromatographic properties of glyme polysiloxane stationary phases. The operation temperature range of these phases was 20-280°C.…”

Section: Introductionmentioning

confidence: 99%

Open crown ether polysiloxane stationary phases for capillary gas chromatography

Cai

Han

1995

Abstract. In this paper, two new open crown ether polysiloxane stationary phases were prepared for capillary gas chromatography. Chromatographic characteristics, including column efficiency, operational temperature range, thermal stability, and polarity were studied. The open crown ether polysiloxane was found to have unique selectivity for alcohols, aromatic hydrocarbons, and nitrogen-containing compounds. The separation mechanism and various thermodynamic parameters are discussed.

“…Rouse et al (6) and Wu et al 0 recently prepared crown ether substituted polysiloxanes with spacers of three or eleven methylene groups between the polysiloxane backbone and crown ether groups, which showed high efficiency, high thermostability, and a unique selectivity for some compounds. In our previous work (S), a 3-propylbenzo-15-crown-5 was substituted onto a polysiloxane backbone to yield a stationary phase, which was coated on fused silica capillary columns, producing excellent separations of isomers of cresol, dimethoxybenzene, mono-and dinitrotoluene, etc.…”

Section: Introductionmentioning

confidence: 99%

Crown ether substituted polysiloxanes as stationary phases for open tubular column gas chromatography

Zhang

et al. 1991

Abstract. Two new crown ether substituted polysiloxanes, 4-propylbenzo-15-crown-5 polysiloxane (PSO-B-15C5) and propyloxydibenzo-14-crown-4polysiloxane (PSO-DB-14C4), were prepared and used as stationary phases coated on fused-silica open tubular columns. The chromatographic characteristics, including column efficiency, polarity, phase transition temperature, allowable operating temperature range and selectivity, were studied. A unique selectivity of these columns was found for the separation of all six dimethylphenol isomers. The separation mechanism is discussed.