Simultaneous determination of PAHs, hetero-PAHs (N, S, O), and their degradation products in creosote-contaminated soils. Method development, validation, and application to hazardous waste sites

A simple and reproducible method which provides the simultaneous determination of PAHs and hetero-PAHs (N,S,O) and their metabolites in contaminated soils has been developed, Contaminants extracted from the soil sample were separated by polarity and acid-base characteristics using solid phase extraction (SPE) on silica gel and a strong basic anion exchange material. A subfraction containing PANHs and neutral metabolites was subsequently fractionated into neutral and basic compounds using a strong acidic cation exchange material. The identification and quantification was performed using different GC and HPLC methods. A method validation was carried out for 21 PAHs, 22 hetero-PAHs, and 19 metabolites in a five-level matrix calibration. Uncontaminated soil (AhA1-layer/compost mixture) was spiked with the chosen standard compounds. The method showed good linearity (coefficient of correlation) and high precision (coefficient of variation) for major and minor compounds over a wide range of concentration as well as high sensitivity (limit of detection). The method was successfully applied to different authentic tar oil contaminated sites. Aside from the typical tar oil PAHs, hetero-PAHs and metabolites predominantly with ketonic or quinonic structure were identified on a mg/kg concentration level.