Suitability of different plastic materials for head or nose spaces short term storage

Three types of plastic material (Saran, Tedlar and Teflon) were examined for their influence on the profile of a model headspace containing 13 volatile compounds of different volatility and polarity. As far as the emission of contaminants from the bags to the headspace is considered, the most appropriate material is obviously Teflon. However, the drawback of this material is a rapid sorption and then a slow adsorption of most volatile compounds tested, in particular polar ones. The authors suggest that acceptable time for headspace storage is between 4 and 12 hours, but with possible loss of the most polar compounds pre- sent in trace quantities.