Fig 5. The isotope label of topically applied D₃-stearic acid is incorporated into the pheromone component.

(A) Total ion chromatogram (TIC) of a hexane extract of a pheromone gland treated with D₃-stearic acid. Z7,Z10-16:Ald = (7Z,10Z)-7,10-hexadecadienal, Z7-16:Ald = (Z)-7-hexadecenal, Z9-16:Ald = (Z)-9-hexadecenal. (B) Mass chromatograms show the elution of the isotope-labeled pheromone compound (m/z 239, 196, and 182) slightly earlier than the non-labeled compound (m/z 236, 193, and 179).