Extraction of polycyclic aromatic hydrocarbons from smoked fish using pressurized liquid extraction with integrated fat removal

Quantification of polycyclic aromatic hydrocarbons (PAHs) in smoked fish products often requires multiple clean-up steps to remove fat and other compounds that may interfere with the chemical analysis. We present a novel pressurized liquid extraction (PLE) method that integrates exhaustive extraction with fat retention in one single analytical step. The PLE parameters: type of fat retainer, flush volume, solvent composition, fat-to-fat retainer ratio (FFR), and the dimensions of the extraction cells were the most important factors for obtaining fat-free extracts with high recoveries of PAHs. A 100 mL extraction cell filled with 18 g activated silica gel, dichloromethane:hexane (15:85, v/v) as extraction solvent, FFR of 0.025 and 100% flush volume was the best analytical setup for integrated extraction and fat retention. The one-step procedure provided a more rapid and cost-efficient alternative with minimization of waste generation compared to the standard reference method that is based on a multi-step procedure. Furthermore, the analytical quality of the two methods are comparable, while the new integrated approach for extraction and cleanup is less prone to analytical errors (random and systematic) because of fewer analytical steps.