Floral scent is often composed of hundreds of VOCs, in very variable proportions. The method used is a tradeoff between accurately detecting quantifying minor compounds and avoiding detector saturation by major compounds. For most analysis methods routinely used, the detection threshold of many VOCs is still higher than the perception threshold of insects, which reduces our capacity to understand plant-insect interactions mediated by floral scent.
Further, the chemical diversity in floral scent samples is challenging. The time of analysis is proportional to the range in molecular weight of VOCs present in the sample, hence a high diversity will increase analysis time. Floral scent may also be composed of very similar molecules, such as isomers and especially enantiomers, which tend to co-elute and then to be very hardly separated. Unambiguously detecting and quantifying them is of importance though, as enantiomers may trigger very different responses in pollinators.