Analysis of volatile organic compounds by thermal desorption chromatography mass spectrometry (TD-GC-MS): Breakthrough phenomenon, a parameter to take into account.

Plants emit diverse volatile organic compounds (VOCs) that are involved in defense, communication, and pollinator attraction. As part of a broader study on VOCs emitted by lavandin fields, VOCs were sampled using a dynamic method involving sorbent tubes containing Tenax TA, followed by thermal desorption and gas chromatography-mass spectrometry analysis. Different parameters were optimized to ensure efficient results. Breakthrough, which causes a loss of molecules in the sampling tubes, was investigated for some molecules of interest, with the aim of quantifying and limiting it. Breakthrough was observed in the field and reached 65% for some compounds, and results showed it was reduced by cooling the tubes during sampling. A new, transportable device was developed to control the temperature around the tubes. The device was validated in laboratory conditions using lavandin essential oil. To complete this study, the cooling device was validated in the field in hot summer conditions reducing breakthrough to below 5% for all target compounds, an acceptable level for reliable quantification.