Abstract. The aroma compound ethyl butyrate (EB) and its methylated derivatives ethyl 2-methylbutyrate (EM), ethyl isovalerate (EI), and isopropyl butyrate (IB) are present in many consumer products. ...

Organosulfates (OSs) form a significant component of secondary organic aerosol (SOA) in the atmosphere. Previously, their measurement using reversed-phase liquid chromatography–high-resolution mass spectrometry (RPLC–HRMS) has led to poor retention and significant matrix effects. Hydrophilic interaction liquid chromatography (HILIC) provides improved retention of polar OSs, such as those formed from isoprene oxidation, and reduced matrix effects. Studies employing HILIC predominantly use gradient elution to separate OSs with varying polarities. HILIC, however, is very sensitive to changes in the water layer within the column, which facilitates separation, meaning the column needs to be thoroughly equilibrated before each injection, significantly increasing analysis time, cost, and solvent waste. The work presented here describes the development of an isocratic HILIC method to analyze OSs in complex ambient PM2.5 samples. This new method significantly reduces solvent usage and analysis time, which is vital for the analysis of large quantities of samples. The method was first validated with synthesized isoprene-derived OS tracers (iOS) and commercially available standards, then applied in the iOS analysis of filter samples collected during the summertime in Manchester, England. Eight filter samples were taken each day, allowing the temporal evolution of iOS tracers to be elucidated. For 336 ambient samples analyzed in this work, the adoption of the isocratic method resulted in a total time saving of 61 h and reduced organic solvent usage by 1.68 L. The targeted analysis of iOS was quantified using authentic standards. Five 2-methyltetrol OS isomers were quantified (C5H12O7S; MTOS_1–4, 6) averaging 0.36, 0.11, 1.25, 2.12, and 0.17 ng m–3, respectively. The average concentration of total 2-methyltetrol OS was 3.99 ng m–3, and 2-methylglyceric acid OS (C4H8O7S: MGOS) was 1.07 ng m–3.

Guaiacol (2-methoxyphenol) is an oxygenated aromatic volatile organic compound (VOC) emitted from biomass burning during lignin pyrolysis with significant potential to impact air quality through tropo...

The National Centre for Atmospheric Science can confirm that the FAAM Airborne Laboratory will cease operations at the end of this financial year, following the withdrawal of funding by UKRI-NERC.

NERC is transitioning its funding of atmospheric science infrastructure to exploit more flexible, scalable and sustainable technologies.

Scientists at University of York were delighted to be recognised with an “outstanding research paper” award from the Royal Society of Chemistry.

Researchers using aircraft to sample exhaust plumes say infringements persist – even in stricter zones

npj Climate and Atmospheric Science - Largely underestimated production of isoprene epoxydiols (IEPOX) through high-NO oxidation pathways in urban areas

In isoprene oxidation, epoxides are crucial for forming isoprene-derived secondary organic aerosol (iSOA), significantly impacting the global atmospheric aerosol burden and composition. Isoprene dihydroxyepoxydiols (IEPOX) and hydroxymethyl–methyl-α-lactone (HMML) are key reactive gas-phase intermediates under low- and high-NO conditions, respectively. IEPOX and/or HMML can undergo nucleophilic reactions with both sulfate and water, producing isoprene-derived organosulfates (iOSs) and oxygen-containing tracers (iOTs). In this study, high temporal observations of iSOA species indicate that although OS formation in the urban and forest areas exhibited similar diurnal variations, the average concentrations of biogenic OSs decreased significantly from the urban site to the forest site. Additionally, at the urban site, the nucleophilic addition reaction is more likely to occur with sulfate (iOSs/iOTs = 1.51), while at the forest site, water serves as the dominant reactant (iOSs/iOTs = 0.81). We have also estimated the branching ratios of nucleophilic reaction pathways with sulfate and water at the different sites. At the Guangzhou urban site, the branching ratio of IEPOX with sulfate:water has a mean of 42.4%:57.6%, whereas for HMML, it is 64.3%:35.7%. At the forest site, the branching ratio of IEPOX with sulfate:water is roughly equal at 48.3%:51.7%, while for HMML, the preference is for reaction with water with a ratio of 33.7%:66.3%. Furthermore, the concentrations of iOSs were significantly correlated with the product of [O3]·[SO42–]. This correlation was stronger than the individual correlations of major iOSs with [O3] and [SO42–]. Thus, higher levels of OS were attributed to enhanced photochemical processing and increased levels of sulfate. This research offers valuable insights into the impacts of biogenic–anthropogenic interactions and the factors controlling the formation of iSOA in polluted areas via nucleophilic addition reactions.

Royal College of Physicians also says poor air quality costs country more than £500m a week

A new study has revealed a significant shift in the sources of nitrogen oxides (NOx) pollution in central London, with gas boilers used for heating now identified as the primary contributor.

YouTube video by WACL

PhD Project - Understanding air pollution in a warming world at University of York, listed on FindAPhD.com

Abstract. Chemical mechanisms form the core of atmospheric models to describe degradation pathways of pollutants and ultimately inform air quality and climate policymakers and other stakeholders. The ...

The University of York is collaborating with institutions across the UK to help train and support the next generation of doctoral researchers.

The aim of this project is to determine what impact higher average temperatures and extreme temperature events will have on concentrations of volatile organic compounds in cities and how these might l...