Ultrafast sampling and analysis of plant volatiles by a hand-held miniaturised GC with pre-concentration unit: Kinetic and quantitative aspects of plant volatile production

Abstract

A method has been developed for continuous monitoring of the emission of volatiles from biological sources with high time resolution. High time resolution (up to 3 min) is achieved by an automatically operated, miniaturised gas chromatographic system equipped with a pre-concentration unit (zNose™). After calibration, the zNose™ provides reliable quantitative data for individual compounds and allows their emission kinetics to be followed over longer periods of time without supervision. While the results of the zNose™ provide information about actual composition of aromas during sampling, the analysis of simultaneously trapped volatiles supplies information about the total amount of emitted compounds and permits further spectroscopic analyses (Isotope-Ratio-MS, GC-MS, etc.). Both methods, analysis by the zNose™ and sampling on charcoal traps, lead to comparable results. The new analytical system has been successfully used to study the kinetics of volatile emission from elicitor-treated Lima bean leaves (Phaseolus lunatus), aphid-damaged paprika plants (Capsicum annuum), and to follow the volatile emission from blossoms of the cactus Rebutia fabrisii over several days. The instrument is portable and can be used in the field.