Journal article

Oxalate metal complexes in aerosol particles: Implications for the hygroscopicity of oxalate-containing particles

Furukawa T, Takahashi Y ...see all

Atmospheric Chemistry and Physics, vol. 11, issue 9 (2011) pp. 4289-4301

  • 28

    Readers

    Mendeley users who have this article in their library.
  • 36

    Citations

    Citations of this article.
  • N/A

    Views

    ScienceDirect users who have downloaded this article.
Sign in to save reference

Abstract

Atmospheric aerosols have both a direct and an indirect cooling effect
that influences the radiative balance at the Earth's surface. It
has been estimated that the degree of cooling is large enough to
weaken the warming effect of carbon dioxide. Among the cooling factors,
secondary organic aerosols (SOA) play an important role in the solar
radiation balance in the troposphere as SOA can act as cloud condensation
nuclei (CCN) and extend the lifespan of clouds because of their high
hygroscopic and water soluble nature. Oxalic acid is an important
component of SOA, and is produced via several formation pathways
in the atmosphere. However, it is not certain whether oxalic acid
exists as free oxalic acid or as metal oxalate complexes in aerosols,
although there is a marked difference in their solubility in water
and their hygroscopicity. We employed X-ray absorption fine structure
spectroscopy to characterize the calcium (Ca) and zinc (Zn) in aerosols
collected at Tsukuba in Japan. Size-fractionated aerosol samples
were collected for this purpose using an impactor aerosol sampler.
It was shown that 10–60% and 20–100% of the total Ca and Zn in the
finer particles (respectively. Oxalic acid is hygroscopic and can thus increase the
CCN activity of aerosol particles, while complexes with various polyvalent
metal ions such as Ca and Zn are not hygroscopic, which cannot contribute
to the increase of the CCN activity of aerosols. Based on the concentrations
of noncomplexed and metal-complexed oxalate species, we found that
most of the oxalic acid is present as metal oxalate complexes in
the aerosols, suggesting that oxalic acid does not always increase
the hygroscopicity of aerosols in the atmosphere. Similar results
are expected for other dicarboxylic acids, such as malonic and succinic
acids. Thus, it is advisable that the cooling effect of organic aerosols
should be estimated by including the information on metal oxalate
complexes and metal complexes with other dicarboxylic acids in aerosols.

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Get full text

Authors

  • T. Furukawa

  • Y. Takahashi

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free