A portable gas chromatograph with simultaneous detection by mass spectrometry and electroantennography for the highly sensitive in situ measurement of volatiles

Mating disruption is a sustainable method for the control of insect pests, involving the release of synthetic sex pheromones that disrupt the olfactory localization of females by males. However, the development and refinement of this strategy is hampered because current instruments lack the sensitivity to detect volatile organic chemicals in the field, and portable electroantennograms produce non-comparable relative units and distorted results in the presence of plant volatiles. To address the demand for more sensitive instruments that are suitable for the rapid in situ detection of airborne pheromones, we have developed a portable, automated needle trap device connected to a gas chromatograph, mass spectrometer, and electroantennographic detector (NTD-GC-MS/EAD) suitable for field applications. We tested the instrument by measuring the concentration of the sex pheromone (E,Z)-7,9-dodecadienyl acetate, which is used to disrupt the mating of the European grapevine moth Lobesia botrana (Lepidoptera: Tortricidae). Our data confirm that the instrument generates highly reproducible results and is highly sensitive, with a detection threshold of 3 ng/m(3) (E,Z)-7,9-dodecadienyl acetate in outside air.