A VERSATILE METHOD FOR ONLINE ANALYSIS OF VOLATILE COMPOUNDS FROM LIVING SAMPLES

A system especially designed for the on-line analysis of volatiles emi tted by living aerobic organisms is described. The instrument consists of a modified thermal desorber and utilizes the purge and cold trap ( PCT) technique coupled with gas chromatography-mass spectrometry. The system enables the use of a variety of sample vessels especially adapt ed to individual test organisms. Quantitative analyses of some volatil e semiochemicals revealed that when only nanogram amounts of these com pounds are evaporated at room temperature for a period of 10 min, they may be trapped and detected by this device. Emission of volatiles fro m two insect species and a plant species have been studied in detail b y using this system.