Gschwend%20thesis.pdf

Short-term Temporal Studies.
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The o-xylene concentration in samples from CD acquired before, during,
and after summer weekends is shown in figure 4-1. In the first study
(May 26 .- June i, 1978), the concentration of o-xylene was greatly increased
after the weekend, relative to before the weekend, In the other 2 cases
(July 14-19, 1978; August 31 - September 6, 1978) samples were taken during
the weekend and showed that the concentration of o-xylene increased during
tha t time. Notably, the early part of these weekends did not have peak
concentrations; in July the highest concentration was found on Sunday while
in September this maximum occurred on Saturday afternoon.. This indicates
either a delay in the water response to heightened atmospheric levels or
that recreational activities on Saturday afternoon provide these aromatic
compounds. The Saturday afternoon sample on September 2 was taken while
two power boats were towing water skiers in the vicinity of CD. This was
the highest concentration ever observed and undoubtedly derived chiefly
from these motorboats.
Isomer Distributions
Isomer distributions were studied in an effort to "fingerprint" the
sources of the c2- and C3-benzenes. Interpretation of isömer distributions
in seawater is difficult due to differential effects of environmental
processes which operate on an isomer distribution. However, llyoung'! dominant
sources should leave revealing "fingerprints,"
Gasoline, gasoline/oil for outboard engines, and fuel oil were diluted
and analyzed directly by gas chromatography (GC). Auto exhaust was collected