Characterization of Modified Silica Gel as a Source of Ethene for Standard Gaseous Mixtures

The application of chemically modified silica gel as a source of gaseous standard mixture containing ethene as a measured component is described. The surface of silica gel was chemically modified, which resulted in the formation of N-oxide of diethylaminopropylsilylated silica gel. This compound undergoes thermal decomposition at 245°C, yielding known amounts of ethene. The process of thermal decomposition of chemically modified silica gel took place in a desorber furnace connected on-line via a four-port valve to the device being calibrated. Such a solution provides convenient calibration of a GC/FID system after direct introduction of a stream of the generated mixture onto the front of a GC. It was found that 480 ± 15 mg of ethene can be generated per 1 g of the modified gel.