Optimization and validation of a method using UHPLC-fluorescence for the analysis of polycyclic aromatic hydrocarbons in cold-pressed vegetable oils.

Among the different food categories, the oils and fats are important sources of exposure to polycyclic aromatic hydrocarbons (PAHs), a group of organic chemical contaminants. The use of a validated method is essential to obtain reliable analytical results since the legislation establishes maximum limits in different foods. The objective of this study was to optimize and validate a method for the quantification of four PAHs [benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(a)pyrene] in vegetable oils. The samples were submitted to liquid-liquid extraction, followed by solid-phase extraction, and analyzed by ultra-high performance liquid chromatography. Under the optimized conditions, the validation parameters were evaluated according to the INMETRO Guidelines: linearity (r2 >0.99), selectivity (no matrix interference), limits of detection (0.08-0.30μgkg-1) and quantification (0.25-1.00μgkg-1), recovery (80.13-100.04%), repeatability and intermediate precision (<10% RSD). The method was found to be adequate for routine analysis of PAHs in the vegetable oils evaluated.