Sampling the Body Odor of Primates: Cotton Swabs Sample Semivolatiles Rather Than Volatiles

Abstract

We assessed the suitability of a frequently used sampling method employing cotton swabs for collecting animal body odor for gas chromatography-mass spectrometry (GC-MS) analysis of volatile organic compounds (VOCs). Our method validation showed that both sampling material and sampling protocols affect the outcome of the analyses. Thus, among the tested protocols swabs of pure viscose baked before use and extracted with hexane had the least blank interferences in GC-MS analysis. Most critical for the recovery of VOCs was the handling time: the significant recovery losses of volatiles experienced with this sampling procedure suggest that a rapid processing of such samples is required. In a second part, we used swab sampling to sample the body odor of rhesus macaques (Macaca mulatta), which lack scent glands. First results after GC-MS analysis of the samples collected from these nonhuman primates emphasize that proper analytical performance is an indispensable prerequisite for successful automated data evaluation of the complex GC-MS profiles. Moreover, the retention times and the nature of the identified chemical compounds in our samples suggest that the use of swabs is generally more appropriate for collecting semivolatile rather than VOCs.

Keywords: GC-MS profiling; body odor; rhesus macaques; semivolatile organic compounds (sVOCs); validation of swab sampling; volatile organic compounds (VOCs).