2024-05-07 カナダ・ブリティッシュコロンビア大学(UBC)
＜関連情報＞
- https://news.ubc.ca/2024/05/pancakes-brussels-sprouts-and-stir-fry-oxidant-detected-indoors/
- https://pubs.rsc.org/en/Content/ArticleLanding/2024/EA/D3EA00167A
一重項酸素は室内照明下で褐色炭素含有調理用有機エアロゾル（BrCOA）から生成される Singlet oxygen is produced from brown carbon-containing cooking organic aerosols (BrCOA) under indoor lighting
Nadine Borduas-Dedekind, Keighan J. Gemmell, Madushika Madri Jayakody, Rickey J. M. Lee, Claudia Sardena and Sebastian Zala
Environmental Science:Atmospheres Published:18 Apr 2024
DOI:https://doi.org/10.1039/D3EA00167A
Abstract
Light absorbing organic molecules known as brown carbon (BrC) can be emitted during processes such as cooking and combustion in indoor environments. We hypothesized that indoor BrC-containing cooking organic aerosols, or BrCOA, can act as sensitizers to generate the first excited state of molecular oxygen, singlet oxygen (1O2*), under indoor lighting conditions. Here, we used an impinger to collect aerosols from a range of cooking dishes, including pancakes, pan-fried Brussels sprouts and vegetable stir-fries, and irradiated these samples in a photoreactor with UVA and fluorescent lights and on a sunlit windowsill. Using furfuryl alcohol as a probe for 1O2*, we determined steady-state concentrations of 1O2* using liquid chromatography and calculated apparent quantum yields for each BrCOA sample. Our results show that under all indoor lighting conditions tested, BrCOA can indeed sensitize 1O2*. Specifically, in solutions of BrCOA from pancakes, pan-fried Brussels sprouts, and vegetable stir-fries under UVA light, the 1O2* concentrations were 2.56 ± 1.24 × 10−13 M, 2.24 ± 1.51 × 10−13 M, and 3.12 ± 0.86 × 10−13 M, respectively. These results suggest that 1O2* production is not dish-dependent, but rather produced across a range of BrCOA samples. We then normalized the 1O2* concentrations to the rate of absorbance to obtain apparent quantum yields up to 6.1%. Both the quality and the quantity of the chromophoric BrCOA were important for predicting the apparent quantum yield. Moreover, the indoor sunlit experiments led to the highest 1O2* concentrations observed, with important implications on the formation of oxidants in sunlit kitchens. These results demonstrate the ability of BrCOA to produce 1O2* in indoor environments, and thus for 1O2* to be a competitive indoor oxidant.
