GC DETERMINATION OF VOLATILE COMPONENTS IN HUMAN EXHALATION AND IN AMBIENT ATMOSPHERE, AFTER PRECONCENTRATION ON SOLID SORBENTS

A modified GC sampling system and its analytical use are described for the determination of volatile components of human breath or in ambien t atmosphere with flame-ionization detection (FID). The difficulties o f collection for low concentration samples were alleviated by using a very small trapping column packed with activated charcoal. The collect ed samples can be measured directly after thermal desorption onto the chromatographic column (packed with Porapak Q). The preconcentration r ecoveries for pentane, methanol, ethanol and acetone have been studied .