Gschwend%20thesis.pdf

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were conducted. Rain samples were analyzed to indicate the potential of
the atmosphere as a source. Fresh and brackish water samples from inland
sites were investigated to test the importance of runoff. Finally,
a brief effort was made to determine the concentrations of the C2- and C3-
benzenes in air.
METHODS
Water samples were analyzed for volatile organic compounds by the
methods of Grob and ZUrcher (1976) and Schwarzenbach et al. (1978).
RESULTS AND DISCUSSION
In order to simplify discussion, only o-xylene (1,2-dimethyl benzene)
concentrations will be considered except in the isomer distribution
This is reasonable since all the C2- and C3-benzenes covary to a first
studies .
approxima tion, and since o-xylene is cleanly resolved in the chromatograms.
Year-round Chemotaxis Dock Seawater Data. .
As noted in Chapter 3J the concentrations of o-xylene in samples from
the year-round studywere higher immediately after summer weekends (figure
3-10) . This suggested an anthropogenic source related to recreational
activities at that time of year.
If the C2- and C3-benzenes were delivered to Chemotaxis Dock (CD) from
one dominant source (e.g. Woods Hole harbor), one should observe an influence
of .the tide on these aromatic compound concentrations, Accordingly, the
concentrations of these aromatic compounds in the biweekly samples from CD
in the year-round study were considered as a function of the tide at the