Fast screening of terpenes in cosmetics by fluorescence quenching of the bovine serum albumin-fluorescein system confined in a single drop

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The presence of fragrances in cosmetics could be a problem of health concern, since some of the employed chemicals may induce asthma, migraines headaches and other adverse effects. In fact, the European Union has established a list of 26 potential allergens used as fragrances, 23 of them being volatiles terpenes. These substances may act also at low concentrations and therefore their analytical monitoring is desirable, even in theoretically fragrance-free products. Researchers from the University of Vigo (Spain) have recently presented in a research article, published in Analytica Chimica Acta, a rapid screening method for terpenes in cosmetics. This approach is based on the potential fluorescence quenching that these hydrophobic compounds induce in the bovine serum albumin (BSA)- fluorescein (F) system.

The potential quenching effect of terpenes in BSA-fluorescent indicator systems is well reported in the literature. However, this general approach does not allow the determination of terpenes at low concentrations. This shortcoming has been overcome confining the BSA-F system in an aqueous drop which is exposed to the headspace of the sample (see Figure 1), after a simple preparation process. The headspace single drop microextraction step provides a preconcentration of the targets improving the sensitivity of the determination, providing a limit of quantification as low as 0.57 µg/g.

Single drop microextraction using bovine serum albumine-fluorescein sytem as probe

This screening method provides a general index of terpenes in the cosmetic sample thanks to the similar quenching effect observed for the tested analytes. It is simple (it only requires a dissolution of the sample in a ethanolic mixture) and rapid (it spends only 10 min) and it can be used in routine analysis with excellent precision.

For further details, readers are referred to the original article. They will find there the complete procedure, the optimization process as well as the analytical characterization of the final approach.

Link to the article: Fast screening of terpenes in fragrance-free cosmetics by fluorescence quenching on a fluorescein–bovine serum albumin probe confined in a drop

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