Gschwend%20thesis.pdf

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hydrogens of the C2- and C3-benzenes, are very reactive with atmospheric
free radicals (e.g~ OH'). Darnall et al. (1976) report that terpenes
(limonene and beta-pinene) are attacked by OH' 1~3 times faster than the
most reactive C3~benzene. Therefore, decomposition of individual terpenes
is faster than that for C2- and C3-benzenes during atmospheric transport.
Relative transfer into seawater may be described by consideration of the
relative partition coefficients, Solubility data for terpenes are not
available, but an estimate of these values may be made using an empirical
+
relationship 'of molar volume and log solubility (McAuliffe, 1966). Utilizing
this approach, one finds that terpenes are about an order of magnitude
less soluble than Cz- and C3-benzenes. Thus since vapor pressures for
terpenes are similar to those of Cz - and C3-benzenes, one may conclude
that the terpenes will partition between air and seawater such that the
proportion of a terpene compound dissolved in seawater will be .about an
order of magnitude less than that for C2- and C3-benzenes. If atmospheric
contributions to the C2- and C)-benzenes in coastal seawater at CD
support the observed background levels of 1-IO ng/kg (chapter 4), then
terpenes could well be present at less than O.L-L ng/kg, hence escaping
detection.
Future Work
While this thesis adds to our knowledge of the spectrum of low-polarity
organic compounds in the analytical window from n-octane to n-pentadecane,
additional work is still required to determine the volatile organic fraction
boiling between n-pentane and n-octane. This unstudied fraction contains
many of the compounds used as solvents and consequently may reveal strong