Sensenet can help you support your product claim by understanding the release of volatiles after application on skin or hair!
The challenge
- A well known brand of cosmetics needed an odour comparison test by means of GC-Sniffing-ToFMS analytical technique of a silicone emulsion used in personal hygiene products.
- Two types of samples, a reference emulsion and an adulterated one, were analysed and compared in terms of odour perception and VOC composition.
Our strategy
- A volume of 30 ml of each sample (reference and adulterated silicone emulsions) was used for the analysis (Fig 1a).
- Samples emulsions were previously stirred and then introduced and confined in a microchamber/thermal extractor each at the temperature of 35ºC (Fig 1b).
After 5 minutes under these conditions, an adsorbent tube (Tenax) was inserted on the top of the microchamber to promote the transport of the volatile organic compounds from the headspace to the tube, by means of a flow of nitrogen carrier gas (99.999% purity N2). The acquisition time of the sample in the tube was 5 minutes with a N2 flow of 50 ml/min, being the total collected volume of 250 ml. The sample tube was kept closed with two plugs at its ends until the time of analysis.
Results
More than 80 individual odours were detected by sensory evaluation GC-Sniffing in both samples. We selected those odours that had a different sensory assessment or were detected in only one of the samples. Figure 1 represents the odour profile based on sensory differences.
Notable differences in plastic and floral notes are depicted in Figure 1, which can be attributed as unpleasant and pleasant respectively.
In this sense, it can be seen that the reference sample is favoured by a greater amount of pleasant floral notes and less in unpleasant characters (plastic).
Table 1 show some of the descriptors found in the analysis of both samples by GC-Sniffing versus time analysis (rt), plus their corresponding chemical identifications.
Of the compounds shown in Table 1, except m,p-xylene and isoamyl acetate, the remainder was identified both sensory and chemically but only in the adulterated sample. This shows that it is possible to reduce the volume of search for potential chemical responsible candidates for the smell of the defective sample.
