Abstract:
Part I - Fluorinated Compounds
A method has been developed for the extraction, concentration, and
determination of two unique fluorinated compounds from the sediments of Lake
Ontario. These compounds originated from a common industrial landfill, and
have been carried to Lake Ontario by the Niagara River. Sediment samples from
the Mississauga basin of Lake Ontario have been evaluated for these compounds
and a depositional trend was established. The sediments were extracted by
accelerated solvent extraction (ASE) and then underwent clean-up, fractionation,
solvent exchange, and were concentrated by reduction under nitrogen gas. The
concentrated extracts were analyzed by gas chromatography - electron capture
negative ionization - mass spectrometry.
The depositional profile determined here is reflective of the operation of the
landfill and shows that these compounds are still found at concentrations well
above background levels. These increased levels have been attributed to physical
disturbances of previously deposited contaminated sediments, and probable
continued leaching from the dumpsite.
Part II - Polycyclic Aromatic Hydrocarbons
Gas chromatography/mass spectrometry is the most common method for
the determination of polycyclic aromatic hydrocarbons (PAHs) from various
matrices. Mass discrimination of high-boiling compounds in gas chromatographic
methods is well known. The use of high-boiling injection solvents shows
substantial increase in the response of late-eluting peaks. These solvents have an
increased efficiently in the transfer of solutes from the injector to the analytical
column. The effect of I-butanol, I-pentanol, cyclopentanol, I-hexanol, toluene
and n-octane, as injection solvents, was studied.
Higher-boiling solvents yield increased response for all PAHs. I -Hexanol
is the best solvent, in terms of P AH response, but in this solvent P AHs were more
susceptible to chromatographic problems such as peak splitting and tailing.
Toluene was found to be the most forgiving solvent in terms of peak symmetry
and response. It offered the smallest discrepancies in response, and symmetry
over a wide range of initial column temperatures.
