Chemical and sensory analysis of a silicone emulsion

These emulsions are designed to replace organic solvents. Due to its use as a raw material, its quality assurance can mean significant risk reduction in the final product malformations. Small changes in the composition of a raw material can have a negative impact on sensory terms, significantly affecting the quality of a product.

In the particular case of odours, they can have a direct effect on the consumer, since, among other aspects, they can alter the identity of the product. In more specific terms, odours are interpretations of our brain to stimuli caused by volatile substances that reach the sensory receptors of human nose.2 These substances are relatively small and may belong to different classes of chemical families. In order to be sensorially perceived, odour molecules must overcome a threshold concentration in the air, which varies from one molecule to another. Thus, some molecules can be detected at high concentrations and others from very low concentrations. The latter tend to be associated with unpleasant odours and thus identification can be a difficult task. 

Gas chromatography (GC) coupled to a mass spectrometer (MS), referred to as GCMS, is undoubtedly the most robust and consolidated method in the analysis of volatile organic compounds (VOCs). This technique is able to detect, identify and quantify those VOCs reaching a chemical detector once a sample is introduced into the gas chromatograph. A GC comprises a chromatographic column capable of separating the chemical components of the sample as they progress through it by a carrier gas (usually helium). At the end-oftravel, the diverse (and separated) sample’s components reach the chemical detector (MS) at different times, being subsequently detected and identified.3