Evaluation and optimization of extraction and clean-up methods for the analysis of polycyclic aromatic hydrocarbons in peat samples

Abstract

The analysis of PAH in peat samples is complicated by the high content of organic matter in peat which affects both extraction efficiency and analytical quality. Therefore, we evaluated the efficiencies of three extraction methods (accelerated solvent extraction (ASE), fluidized bed extraction, ultrasonic extraction) and several clean-up techniques in order to find the best set of methods. ASE proved to be the best extraction method. For clean-up, a procedure using aluminium oxide and silica gel showed the highest efficiency, whereas a method originally developed for soil samples failed to remove the peat matrix satisfactorily. With the optimized extraction and clean-up procedure, 170 samples from Canadian bogs were analysed for PAH. With overall recovery rates between 69 ± 14 and 89 ± 16% and an inaccuracy of ≤20%, the optimized method was a well suitable tool for the analysis of PAH in peat samples.

Keywords:

• ASE
• Ultrasonic extraction
• Fluidized bed extraction
• Column chromatography
• PAH

Acknowledgement

We thank the Department of Soil Science and Soil Geography, University of Bayreuth, Germany, for giving us access to the GC-MS instrument.