CRAC Laboratory Activities (1)

CRAC Laboratory Activities (1)

Researcher: Professor John Sodeau

Email: j.sodeau@ucc.ie
Telephone number: 353 (0)21 4902680
http://chemweb.ucc.ie

Project Description

Funding Bodies: EU; EPA, SFI; IRCSET; HEA; INTAS; Cork City Council
Programmes: Marie Curie; ERTDI; Research Frontiers; EMBARK; PRTLI
Project types: PhD students; Postdoctoral Fellows; Capital Equipment
Period: 1999/2000-Funding Bodies: EU; EPA, SFI; IRCSET; HEA; INTAS; Cork City Council
Programmes: Marie Curie; ERTDI; Research Frontiers; EMBARK; PRTLI
Project types: PhD students; Postdoctoral Fellows; Capital Equipment
Period: 1999/2000-

I set up the CRAC (Centre for Research in Atmospheric Chemistry) Laboratory soon after being appointed to the Chair of Physical Chemistry at UCC in 1999/2000. Three other members of academic staff are now involved (Dr John Wenger; Dr Andy Ruth and Dr Dean Venables) along with several PhD students and Postdoctoral Fellows.

My own research is centred on so-called “heterogeneous aspects” of the chemistry that occurs in both the stratosphere and troposphere. The projects were all laboratory based until about three years ago when we were awarded a very large grant from the EU Marie Curie (Transfer of Knowledge) Programme in order to monitor and analyse potentially toxic Particulate Matter (PM2.5), which becomes airborne in Cork. We have recently extended our activities to “catch ship plumes” within the Harbour region (in real-time) and now have a Mobile Laboratory filled with sophisticated equipment to monitor  gases (such as sulfur dioxide, ozone and NOx) along with aerosol/particulates (comprising species such as sulfate ions and elemental carbon). Collected materials are physically and chemically analysed in our laboratory using techniques such as ICP-OES, Ion Chromatography, SEM and GC-MS. We then try to correlate their composition with their effects on real cells in order to determine how toxic the PM actually is (and to determine their source of origin). We hope soon to begin to analyse for specific allergenic, biological components of PM in real-time.

The mechanism by which sulfur dioxide is transformed in aerosols to sulfate ions (i.e. acid rain) is, surprisingly, not well understood. Hence we have set up a novel flow-tube apparatus in our laboratory to monitor the kinetics of transformation along with an FTIR (InfraRed Spectrometer) to determine the actual species that are formed along route. One of the questions that we want to answer in this SFI-funded project is: what, if any, is the role of the elusive sulfonate ion in the overall mechanism?

Finally, we have extended our initial work on determining how the Antarctic ozone “hole” is formed by halogen materials which become (re-)activated by cold, water-ice surfaces in the stratosphere (about 25km altitude) to a number of phenomena much closer to terra firma.  Both the Arctic and Antarctic snow-packs produce pollutants from photolysis by the Sun!  This fact was only recently recognised by field-workers and although many ideas have been put forward to explain why species such as HONO; formaldehyde and BrCl are emitted, little has been definitely proven. Hence we have carried out a number of spectroscopically-based experiments related to this emerging field, termed “cryospheric” chemistry, using techniques such as Raman, UV-Vis, mass spectrometry and FT-RAIRS to investigate what is going on. Some of the publications below will give you an idea of our progress.

So, where to next? Wait for the next update at the CRAC laboratory 10th Anniversary celebration in 2009.

Selected Publications

1. “Potential role of the nitroacidium ion on HONO emissions from the snowpack” Hellebust S, Roddis T JR Sodeau Letter: Journal of Physical Chemistry A. 111: 1167-1171 (2007)
2. “An overview of snow photochemistry: Evidence, mechanisms and impacts”. Grannas AM, JR Sodeau, et al Atmos. Chem. Phys.. 7 4329-4373 (2007)
3. “Halogens and their role in polar boundary-layer ozone depletion”. Simpson WR, JR Sodeau, et al Atmos. Chem. Phys.. 7 4375-4418 (2007)
4. “Freezing halide ion solutions and the release of interhalogens to the atmosphere” P. O’Driscoll, K. Lang, N. Minogue and JR Sodeau. Letter: J. Phys. Chem. (A) 110, 4615-4618, (2006).

Environmental Research Institute

University College Cork, Lee Road, Cork

Top