Gamma radiation induced immobilization of several polydimethylsilane liquid stationary phases for use in packed-column gas chromatographic separations has been studied. Extraction tests show that moderate doses of gamma radiation (80-140 kGy) are sufficient to produce significant (90%) immobilization of most polydimethylsilanes onto Chromosorb supports, although a molecular mass effect is seen. Thermal stability also increases significantly with radiation dose, suggesting higher temperature use with smaller volatility losses. Infrared spectra confirm the continued presence of the stationary phase on the support after thermal stability tests and after exhaustive in-column washing. The column chromatographic behavior of the immobilized phases is equal to or better than that of the unirradiated phases, except for higher doses (300 kGy) of gamma-radiation. Columns prepared from gamma-immobilized polydimethylsilane have been used successfully in analyses where column contamination from high boiling materials requires frequent column recuperation.
gas chromatography; packed columns; immobilized phases; gamma radiation
