44    A COMPARISON OF SPECTROPHOTOMETRIC
AND GAS CHROMATOGRAPHIC MEASUREMENTS
OF HEAVY PETROLEUM PRODUCTS IN SOIL AND
AQUEOUS SAMPLES
Farhad Nadim, Shili Liu, George E. Hoag, Jiang Ping Chen,
and Robert J. Carley
Environmental Research Institute, Box U-210
Storrs, Connecticut 06269
Orest P. Polishchuk
Dept. of Chemistry
I. Franko State University of Lviv
6 Kyrylo and Methodiy St.
290005, Lviv, Ukraine
I tid mi la V. Sidorova
State University "Lvivska Polytechnica"
POB 7346, 11/55 Dovzendo St.
290070, Lviv, Ukraine
INTRODUCTION
Petroleum hydrocarbons originate from liquid fossil fuels called oil, or more properly, petroleum. Petroleum is a naturally occurring liquid with widely different composition and complexity. Except for a few surface seepages, the vast portion of petroleum is located well below the
surface of the earth and it is extracted only by drilling. Crude oil is a complex mixture of hydrocarbons. Its elemental composition is carbon-hydrogen, with variable quantities of oxygen and
sulfur, and trace amounts of nitrogen, metals, and other elements. Refining of crude oil usually
begins with washing with water to remove salt and other inorganic impurities, followed by distillation to separate the various fractions ranging from methane to asphalt. Fuel oil such as gasoline
and diesel are separated during this procedure. Modern refineries use a procedure called "cracking" to fractionate unused cuts. In this process the material is heated to temperatures above
230°C at different pressures with or without a catalyst. Cracking converts heavy and complex
hydrocarbons to more simple molecules with lower boiling points with the loss of hydrogen (J.
A. Plambeck, 1995).
Being a major industrial nation, the United States uses over 250 billion gallons of oil and petroleum products each year on average. At every point in the oil production, distribution, and
consumption process, oil is invariably stored in storage tanks. The potential for an oil spill is significant, and the effects of spilled oil many times pose serious threats to the environment.
Protecting the ecological system and water resources from petroleum contamination are of
main concern.
PURPOSE OF THIS STUDY
EPA method-418.1, known as TPH-IR is based upon a methodology developed to determine
the oil and grease content of industrial wastewaters, sewage, and sludges. The source methodology is presently documented as Standard Method 5520 in Standard Methods for the Examination
of Water and Wastewater, Seventeenth Edition (1989), jointly published by the American Public
52nd Purdue Industrial Waste Conference Proceedings, 1997, Ann Arbor Press, Chelsea, Michigan 48118. Printed in
U.S.A.
441