The partitioning of ketones between the gas and aqueous phases

Research output: Contribution to journalArticle

38 Scopus citations

Abstract

Most ketones are not significantly hydrated; they therefore retain their chromophore and they could be photolytically degraded in solution yielding a variety of products including carboxylic acids, aldehydes and radicals. It is difficult to accurately model the partitioning of ketones between the gas phase and aqueous phase because of the lack suitable estimates of the Henry's Law constants; consequently the fate and environmental effects of ketones cannot be confidently predicted. Here we report the experimental determination of the Henry's Law constants of a series of ketones that has yielded a simple straight line equation to predict the Henry's Law constants of simple aliphatic ketones: log H* =0.23Σσ* + 1.51; where H* is the effective Henry's Law constant (M atm-1, and Σσ* is the Taft polar substituents constants. The results for 25°C are (M atm-1) CH3COCH3, 32; C6H5COCH3, 110; CH2ClCOCH3, 59; CH3COCOCH3, 74; CF3COCH3, 138. Acetophenone appears to have an abnormally high H*. Most low molecular weight aliphatic ketones are predicted to characterized by H*≥30 M atm-1 and therefore they are expected to be found in the aqueous phase at concentrations of ≥5 - 0.5 μM (given a typical gas-phase concentration range of 1-10 ppbv). The expected rate of decomposition of ketones due to photolysis in hydrometers is briefly discussed.

Original languageEnglish (US)
Pages (from-to)1473-1477
Number of pages5
JournalAtmospheric Environment Part A, General Topics
Volume25
Issue number8
DOIs
StatePublished - 1991

Keywords

  • 2-methyl ketone
  • Henry's Law
  • carbonyl
  • ketone
  • partition
  • partition coefficient
  • photolysis

ASJC Scopus subject areas

  • Pollution

Fingerprint Dive into the research topics of 'The partitioning of ketones between the gas and aqueous phases'. Together they form a unique fingerprint.

  • Cite this