Biomass burning releases many lower molecular weight organic species which are difficult to analyse, but important to the formation of organic aerosol. This study examined a new high-resolution technique to a better characterise these difficult to analyse organic components. Some burning sources analysed in this study, such as cow dung cake and municipal solid waste, released extremely complex mixtures containing many thousands of different lower-volatility organic compounds.
Biomass burning releases many lower molecular weight organic species which are difficult to...
Review status: a revised version of this preprint was accepted for the journal ACP and is expected to appear here in due course.
Emissions of intermediate-volatility and semi-volatile organic compounds from domestic fuels used in Delhi, India
Gareth J. Stewart1,Beth S. Nelson1,W. Joe F. Acton2,a,Adam R. Vaughan1,Naomi J. Farren1,James R. Hopkins1,3,Martyn W. Ward1,Stefan J. Swift1,Rahul Arya4,Arnab Mondal4,Ritu Jangirh4,Sakshi Ahlawat4,Lokesh Yadav4,Sudhir K. Sharma4,Siti S. M. Yunus5,C. Nicholas Hewitt2,Eiko Nemitz6,Neil Mullinger6,Ranu Gadi7,Lokesh K. Sahu8,Nidhi Tripathi8,Andrew R. Rickard1,3,James D. Lee1,3,Tuhin K. Mandal4,and Jacqueline F. Hamilton1Gareth J. Stewart et al.Gareth J. Stewart1,Beth S. Nelson1,W. Joe F. Acton2,a,Adam R. Vaughan1,Naomi J. Farren1,James R. Hopkins1,3,Martyn W. Ward1,Stefan J. Swift1,Rahul Arya4,Arnab Mondal4,Ritu Jangirh4,Sakshi Ahlawat4,Lokesh Yadav4,Sudhir K. Sharma4,Siti S. M. Yunus5,C. Nicholas Hewitt2,Eiko Nemitz6,Neil Mullinger6,Ranu Gadi7,Lokesh K. Sahu8,Nidhi Tripathi8,Andrew R. Rickard1,3,James D. Lee1,3,Tuhin K. Mandal4,and Jacqueline F. Hamilton1
Received: 17 Aug 2020 – Accepted for review: 20 Aug 2020 – Discussion started: 25 Aug 2020
Abstract. Biomass burning emits significant quantities of intermediate-volatility and semi-volatile volatile organic compounds (I/SVOCs) in a complex mixture, probably containing many thousands of chemical species. These components are significantly more toxic and have poorly understood chemistry compared to volatile organic compounds routinely analysed in ambient air, however quantification of I/SVOCs presents a difficult analytical challenge.
The gases and particles emitted during the test combustion of a range of domestic solid fuels collected from across New Delhi were sampled and analysed. Organic aerosol was collected onto Teflon (PTFE) filters and residual low-volatility gases were adsorbed to the surface of solid-phase extraction (SPE) disks. A new method relying on accelerated solvent extraction (ASE) coupled to comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GC×GC-ToF-MS) was developed. This highly sensitive and powerful analytical technique enabled over 3000 peaks from I/SVOC species with unique mass spectra to be detected. 15–100 % of gas-phase emissions and 7–100 % of particle-phase emissions were characterised. The method was analysed for suitability to make quantitative measurements of I/SVOCs using SPE disks. Analysis of SPE disks indicated phenolic and furanic compounds were important to gas-phase I/SVOC emissions and levoglucosan to the aerosol phase. Gas- and particle-phase emission factors for 21 polycyclic aromatic hydrocarbons (PAHs) were derived, including 16 compounds listed by the US EPA as priority pollutants. Gas-phase emissions were dominated by smaller PAHs. New emission factors were measured (mg kg−1) for PAHs from combustion of cow dung cake (615), municipal solid waste (1022), crop residue (747), sawdust (1236), fuel wood (247), charcoal (151) and liquified petroleum gas (56).
The results of this study indicate that cow dung cake and municipal solid waste burning are likely to be significant PAH sources and further study is required to quantify their impact, alongside emissions from fuel wood burning.
Biomass burning releases many lower molecular weight organic species which are difficult to analyse, but important to the formation of organic aerosol. This study examined a new high-resolution technique to a better characterise these difficult to analyse organic components. Some burning sources analysed in this study, such as cow dung cake and municipal solid waste, released extremely complex mixtures containing many thousands of different lower-volatility organic compounds.
Biomass burning releases many lower molecular weight organic species which are difficult to...