Joint International Conference on Long-term Experiments ...

DETERMINATION OF NITROGEN-CONTAINING POLYNUCLEAR AROMATIC
HYDROCARBONS IN SMOKED FOODS BY LIQUID CHROMATOGRAPHY
Lucian Bara
University of Oradea, Faculty of Environmental Protection
26, General Magheru Street, Oradea
ABSTRACT
Several smoked foods were analyzed for basic nitrogen-containing polynuclear aromatic
hydrocarbon (NPAH) content by a relatively rapid liquid chromatographic (LC) technique.
The analyzed products included both domestic and imported market basket commodities.
Nanogram quantities of NPAH standards were detected by UV and fluorescence detectors
connected in series. The NPAHs were extracted from basic aqueous ethanolic solution into
cyclohexane, extracted from cyclohexane into 6N HCl, and extracted back into cyclohexane
after neutralization of the acid.
The NPAHs were then purified by filtering the extract through deactivated basic
alumina. The eluate from this step was concentrated to dryness, and the residue was
dissolved in 95% ethanol and analyzed by LC, using a Vydac C-18 column and acetonitrilewater
(9 + 1) as the mobile phase. Recoveries of 3 NPAHs, 5,7-dimethylbenz acridine,
dibenz acridine, and dibenz acridine, each added to salmon and sausage at the 5 ppb level,
ranged from 62 to 101% by fluorescence measurement and from 64 to 106% by UV
measurement. None of the NPAHs used, as standards were found by either fluorescence or
UV detection at levels greater than or equal to 5 ppb in any of the foods analyzed.
INTRODUCTION
Interest in the production of petroleum substitutes from shale oil and coal has increased. The
increasing use of coal and synthetic fuels may significantly increase the levels of
heterocyclic nitrogen compounds in the environment because of the charasterically higher
level of organic nitrogen in coal and its by-products, compared to other fossil fuels. Many
nitrogen bases, thought to be products of incomplete combustion of organic matter that
contains nitrogen or to be derived from hydrolytic processes similar to those producing
polynuclear aromatic hydrocarbons, have been shown by various types of skin tests to be
toxic, carcinogenic, and mutagenic to terrestrial and aquatic organisms.
Many azaarenes have been identified in sources such as tobacco, automobile exhaust,
high boiling petroleum distillates, crude oil, shale oil, and lake sediments.
The purpose of our investigation was to develop an analytical method for the
extraction, cleanup, and LC analysis of the basic NPAH fractions obtained from some
smoked foods. The foods analyzed included both domestic and imported products.
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