Chromatographic properties of tetramethyl-p-silphenylene-dimethyl, diphenylsiloxane copolymers as stationary phases for gas-liquid chromatography.
Seven tetramethyl-p-silphenylene-dimethyl, diphenylsiloxane copolymers were coated on fused-silica capillary columns to evaluate their properties as stationary phases in gas-liquid chromatography. The capillary columns were tested concerning their selectivity, separation efficiency, column bleed, inertness, elution temperatures, and working range. The following characteristic properties of the silphenylene unit were found: (i) the impact of the silphenylene group on the chromatographic selectivity is similar to that of two dimethylsiloxy groups and half of a diphenylsiloxy group; (ii) silphenylene-siloxane copolymers offer reduced column bleed and increased maximum allowable operating temperature in comparison to polysiloxanes, since the backbone stiffing phenylene group enhances thermal stability; (iii) the elution temperatures of analytes are increased by 15-30 degrees C on silphenylene-siloxane copolymers compared to polysiloxanes; (iv) the silphenylene unit increases the glass transition temperature of the polymers resulting in elevated minimum allowable operating temperatures.
Mayer
Bernhard X
BX
Department of Clinical Pharmacology, University School of Medicine, Vienna University, Währinger Gürtel 18-20, 1090 Vienna, Austria. bernhard.mayer@univie.ac.at
Kählig
Hanspeter
H
Rauter
Walfried
W
D002849:Chromatography, Gas / Q000379:methods*; D011108:Polymers / Q000737:chemistry*; D012833:Siloxanes / Q000737:chemistry*; D013696:Temperature
D011108:Polymers; D012833:Siloxanes