Ageing of columns of homogeneous mixed stationary phases in gas chromatography

Chromatographic columns of homogeneous mixed phase prepared with squalane and polyethylene glycol 1540 have been subjected to an ageing process of about 1700 hours at 100°C followed by a similar period of time at 120°C. Little change is observed at the lower temperature, while at 120°C, a selective loss of the most volatile component of the mixture seems to occur, producing changes in the values of the retention indices obtained