An optimized protocol for large-scale in situ sampling and analysis of volatile organic compounds

Chemical ecology is an ever-expanding field with a growing interest in population- and community-level studies. Many such studies are hindered due to lack of an efficient and accelerated protocol for large-scale sampling and analysis of chemical compounds. Here, we present an optimized protocol for such large-scale study of volatiles. A large-scale in situ study to understand role of semiochemicals in variation in mating success of lekking blackbuck was conducted. Suitable methods for sampling and statistical analysis were identified by testing and comparing the efficiencies of available techniques to reduce analysis time while retaining sensitivity and comprehensiveness. Solid-phase extraction using polydimethylsiloxane, analysis using a semiautomated detection of retention time and base peak, and statistical analysis using random forest algorithm were identified as the most efficient methods for large-scale in situ sampling and analysis of volatiles. The protocol for large-scale volatile analysis can facilitate evolutionary and metaecological studies of volatiles in situ from all types of biological samples. The protocol has potential for wider application with the analysis and interpretation methods being suitable for all kinds of semiochemicals, including nonvolatile chemicals.