Photochemical Degradation of the UV Filter Octyl Methoxy Cinnamate Probed via Laser-Interfaced Mass Spectrometry.

Autor: Wong NGK; Department of Chemistry, University of York, Heslington YO10 5DD, UK., Sereli M; Department of Chemistry, University of York, Heslington YO10 5DD, UK., Anstöter CS; Department of Chemistry, University of York, Heslington YO10 5DD, UK., Dessent CEH; Department of Chemistry, University of York, Heslington YO10 5DD, UK.
Jazyk: angličtina
Zdroj: Molecules (Basel, Switzerland) [Molecules] 2022 Dec 12; Vol. 27 (24). Date of Electronic Publication: 2022 Dec 12.
DOI: 10.3390/molecules27248796
Abstrakt: Octyl methoxycinnamate (OMC) is a common UVA and UVB filter molecule that is widely used in commercial sunscreens. Here, we used gas-phase laser photodissociation spectroscopy to characterise the intrinsic photostability and photodegradation products of OMC by studying the system in its protonated form, i.e., [OMC·H] + . The major photofragments observed were m / z 179, 161, and 133, corresponding to fragmentation on either side of the ether oxygen of the ester group ( m / z 179 and 161) or the C-C bond adjacent to the ester carbonyl group. Additional measurements were obtained using higher-energy collisional dissociation mass spectrometry (HCD-MS) to identify fragments that resulted from the breakdown of the vibrationally hot electronic ground state. We found that the m / z 179 and 161 ions were the main fragments produced by this route. Notably, the m / z 133 ion was not observed through HCD-MS, revealing that this product ion is only produced through a photochemical route. Our results demonstrate that UV photoexcitation of OMC is able to access a dissociative excited-state surface that uniquely leads to the rupture of the C-C bond adjacent to the key ester carbonyl group.
Databáze: MEDLINE
Externí odkaz:
Nepřihlášeným uživatelům se plný text nezobrazuje