EXTRACTION AND QUANTIFICATION OF BENZO[a]PYRENE IN SOIL BY REVERSED PHASE THIN LAYER CHROMATOGRAPHY

Abstract

As research on the biodegradation of benzo[a]pyrene (B[a]P) shifts from laboratory to field based studies, a need has arisen for reproducible, economical, and accurate methods for extraction and quantification of B[a]P. This study describes a method for the analysis of B[a]P using batch extraction techniques with quantification by reversed phase high performance thin layer chromatography (HPTLC) and densitometry. A loam soil was fortified with B[a]P at a level of 100 mg B[a]P kg⁻¹ soil. Several solvents were evaluated as potential soil extraction systems including: acetone, acetonitrile, ethyl acetate, methanol, and methylene chloride:acetone (1:1). Reverse phase thin layer chromatography of B[a]P was performed on hydrocarbon impregnated, C₁₈ reverse phase plates using methanol:acetonitrile (1:1) as the developing solvent. The Rf for B[a]P in this system was found to be 0.52. Recovery of B[a]P from soil ranged from 11% with methanol to 84% with ethyl acetate.