Impact of the Interactions between Fragrances and Cosmetic Bases on the Fragrance Olfactory Performance: A Tentative to Correlate SPME-GC/MS Analysis with That of an Experienced Perfumer

"Seta e Ciliegia" and "Narguile" fragrances were mixed to form a binary blend with chemically stable, non-volatile, odourless, simple bases of different lipophilicity widely used in skin care and hair care formulations, such as caprylic-capric triglyceride, glycerine, paraffin, dimethicone, isopropyl myristate and butylene glycol, with the objective to verify how the olfactory performance of fragrances can be influenced by skin or hair care ingredients. The semiquantitative approach applied in this study aims in providing a practical solution to appropriately combine a fragrance with cosmetic ingredients. Pure fragrance and binary blends were analysed by solid phase microextraction gas chromatography tandem mass spectrometry (SPME-GC/MS), based on the assumption that the solid phase microextraction is able to extract volatile compounds, mimicking the ability of the nose to capture similar volatile compounds. Fifty-seven and forty-four compounds were identified by SPME-GC/MS in pure fragrances "Seta e Ciliegia" and "Narguile", respectively. Once mixed with the bases, the analysis of the blends revealed that a qualitative modification in the chromatograms could occur according to the characteristics of the bases. In general, for both fragrances, blends with glycerin and butylene glycol, which are the most hydrophilic bases among the ones tested, were able to release most of the peaks, that were thus still present in the chromatograms. Differently, in the blends with caprylic-capric triglyceride, most of the peaks are lost. Blends with paraffine, dimethicone and isopropyl myristate showed an intermediate behaviour. These results were thus compared with the sensory evaluation made by an experienced perfumer, capable of assessing the different olfactory performances of pure fragrances and their different binary blends. The evaluation made by the perfumer fitted well with the analytical results, and in the blends where most of the peaks were revealed in the chromatogram, the perfumer found a similar olfactory profile for example with glycerin, butylene glycol, while a modification of the olfactory profile was highlighted when several peaks were not still present in the chromatogram, as it was the case with caprylic-capric triglyceride. Interestingly, when the most typical peaks of a fragrance were still observed in the blend, even if some of them were lost, the olfactory performance was not lost, as was the case of paraffin and isopropyl myristate. In the case of dimethicone, its high volatility was considered responsible for a certain decrease in the fragrance "volume". The results achieved with this investigation can be used to hypothesize that the different compounds of a fragrance, characterized for the first time by different volatility and solubility, could be differently retained by the bases: the more lipophilic are strongly retained by the lipophilic bases with a consequently reduced volatility that limits the possibility of being appreciated by the nose and that corresponds to disappearance or a percentage reduction from the chromatogram. Therefore, in a more accurate and helpful view for a formulator, we could come to the conclusion that based on the results achieved by our investigation, the inclusion of a less lipophilic base can be more appropriate to exalt more lipophilic fragrances.