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Abstract
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In this study, a simultaneous derivatization/air-assisted liquid–liquid microextraction
method has been developed for sample preparation of some phenolic compounds in fuels
and engine oil. Analytes are transferred by back liquid–liquid extraction into NaOH solution
and then are derivatized with butyl chloroformate and extracted simultaneously into carbon
tetrachloride. The extracted derivatized analytes are analyzed using gas chromatography
with flame ionization detection. The effect of extracting solvent type, derivatization agent
and extraction solvent volumes, ionic strength of the aqueous solution, number of extraction
cycles, etc., on the extraction efficiency is investigated. The calibration graphs are linear
in the range of 3–10 000 g/L. Enhancement factors, enrichment factors, and extraction
recoveries are in the ranges of 497 to 1471, 571 to 991, and 60 to 109%, respectively. Detection
limits are obtained in the range of 0.8 to 2.0 g/L. Relative standard deviations for
the extraction of each selected phenols are in the ranges of 2–4% for intraday (n = 6) and
3–6% (n = 5) for interday precisions for 200 g/L. This technique is successfully applied
for the extraction, preconcentration, and determination of the selected phenols in gasoline,
kerosene, gas oil, and engine oil.
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