Singlet oxygen and triplet state production from primary biomass burning organic aerosol from different fuels: Role of solvent-dependent extraction
Bibliographic record
Abstract
Biomass burning organic aerosol (BBOA) is a significant source of brown carbon (BrC), a class of light-absorbing organic compounds that influence climate and atmospheric oxidation chemistry. Certain BrC chromophores act as photosensitizers, producing reactive oxidants such as singlet oxygen (SO) and triplet excited states (TP) upon solar irradiation. However, most studies rely on water extractions, potentially overlooking water-insoluble chromophores that contribute to this photochemistry. In this work, we developed a new organic-solvent extraction method to probe water insoluble chromophores and their ability to sensitize SO and TP, and to understand the ability of multi-phase aerosols to produce these in situ oxidants. Primary organic aerosol (POA) filters from the combustion of beechwood, cow dung, straw, and plastic, collected during the BAMBE campaign, were extracted. We analyzed them using a two-probe photochemical method with furfuryl alcohol (FFA) and syringol as probes to quantify SO and TP steady-state concentrations and quantum yields, respectively, under UVA irradiation. Acetonitrile extraction captured a broader range of chromophores than water, leading to both higher absorbance and enhanced reactive oxidants production. Solvent ratios modulated SO deactivation, with higher acetonitrile content increasing steady-state concentrations through reduced quenching, showing up to 6-fold increase in SO concentrations. Fuel type significantly influenced oxidant yields; beechwood and plastic extracts showed the highest SO and TP production, up to 4.9+/-0.1% for SO and 4.2+/-0.2% for TP. These trends were not solely explained by combustion efficiency, indicating that BrC chemical composition plays a dominant role. Our findings underscore the importance of solvent selection and fuel source in assessing BrC photochemical activity and offer new insight into the oxidative potential of BBOA in atmospheric multiphase environments.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".