Influence of functional groups on the gas chromatographic retention behaviour of QM-siloxanes

Abstract

The retention time sequences of QM-siloxane derivatives (derivatives of trimethylsilyl esters of silicic acids) of the formula QmM2m+2-nXn (X = H, Cl, C2H5O; m, n = 1,2,3) and of siloxane derivatives containing M, D and T groups were investigated by capillary gas chromatography. The investigation showed that in compounds of the same structural type the retention times increase in the order of the substituents H < Cl < C2H5O. A linear correlation between retention time and molecular weight was observed only within groups of QM derivatives of the same structural type. The retention sequence rule obtained from QM-siloxanes was modified so that it became valid for the investigated compounds, and so that it should be possible to identify unknown siloxane derivatives by the use of gas chromatography.