Automated pressurized liquid extraction (PLE) and automated power-prep™ clean-up for the analysis of polycyclic aromatic hydrocarbons, organo-chlorinated pesticides and polychlorinated biphenyls in marine samples

Abstract

An accurate and precise analytical method for the determination of polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and organo-chlorinated pesticides (OCPs) in fish and shellfish based on automated pressurized liquid extraction (PLE) and automated power-prep™ clean-up has been developed. After extraction, the extract was passed through gel permeation chromatography (GPC) using 12 g of Bio-beads SX-3 for fat removal. GC/MS (NCI) was selected for OCPs and PCBs due to its high sensitivity and selectivity of NCI to chlorinated compounds and GC/MS (EI) for PAHs. The method was validated using spiked surrogates of ¹³C-PCBs, deuterated PAH (d-PAHs) and fish reference material (EDF-2525). All of the recoveries are within the acceptance levels and in accordance with the US-EPA standard methods. The calibration ranges for most of the compounds were from 50 to 1000 ng ml⁻¹ for PAHs, 10 to 103 ng ml⁻¹ for PCBs and 10 to 200 ng ml⁻¹ for OCPs. The limits of detection ranged between 0.01 and 0.28 ng g⁻¹ (w/w) for PCBs, 0.03–2.48 ng g⁻¹ (w/w) for OCPs and 0.1 to 1.0 ng g⁻¹ (w/w) for PAHs. Analytical criteria, such as repeatability and reproducibility were evaluated through a range of biological matrices and fish reference material analysis. The feasibility of extraction using a power-prep™/PLE system combined with power-prep™ automated clean-up demonstrated a validated method for the analysis of biota samples.