TITLE:
Trials for Gathering Information on an Unknown Peak in the GC-MS Spectra of Horse and Pony Hair Extracts
AUTHORS:
Maia Tsikolia, Till Opatz, Ulrich Kauhl, Nurhayat Tabanca, Betul Demirci, Saundra H. TenBroeck, Kenneth J. Linthicum, Ulrich R. Bernier
KEYWORDS:
Nonanal, Skin Emanation, Insect Pests, Equus caballus, Equus ferus caballus, Mass Spectroscopy, Structure Elucidation
JOURNAL NAME:
Advances in Entomology,
Vol.9 No.2,
April
28,
2021
ABSTRACT: The volatile compounds from horse and pony hairs and skin were analyzed to determine bioactive molecules that are kairomones used for host location by blood-feeding diptera. In this study, horse and pony hair samples were extracted with organic solvents (pentane or hexane) and analyzed by gas chromatography-mass spectrometry analysis (GC-MS) with closed electron ionization (CEI). Using the GC-MS analysis, we observed a compound peak, which could not be identified by comparison to mass spectra in the mass spectral library. This unknown compound was often the largest peak in the chromatogram and had a retention index and mass spectral fragmentation similar to nonanal. However, there were several differences in the fragmentation pattern. When compared to a nonanal reference standard, it was evident that this was a different compound. Hydrodistillation of pony hair was another extraction method to obtain the unknown component in higher concentrations. Analysis of this extract with GC-flame ionization detector (FID) with GC-MS confirmed the same unknown peak. Further experiments and analysis with the various mass spectroscopy tools gave the possible molecular ion with mass-to-charge ratio (m/z) 142, corresponding to the unknown component.