A rapid method is proposed for the determination of selected H₂SO₄ stable organic compounds-eight organochlorines (OCs; hexachloro-1,3-butadiene, pentachlorobenzene, hexachlorobenzene, hexachlorocyclohexane-HCH-isomers, heptachlor) and six polybrominated diphenyl ethers (PBDEs; BDE-28, 47, 99, 100, 153, 154)-in fish samples. In the method, a modified QuEChERS (quick, easy, cheap, effective, rugged and safe) sample preparation using pH-tuned dispersive liquid⁻liquid microextraction (DLLME) and H₂SO₄ digestion fish extract clean-up is followed by gas chromatography⁻triple quadrupole tandem mass spectrometry (GC⁻QqQ-MS/MS) analysis. The method was validated in terms of linearity, limits of the method, recovery, accuracy, analysis of standard reference material (NIST SRM 1946), and estimation of combined uncertainty of the measurement (top-down approach). For validation, chub composite samples were used, and subsequently, the method was successfully applied to analysis of real samples of eight fish species. Finally, the method passed the analytical Eco-Scale evaluation as "an acceptable green analysis method", and showed its advantages (simplicity, rapidity, low cost, high extract clean-up efficiency, good sensitivity) when compared to other reported QuEChERS based methods.
Keywords: QuEChERS; dispersive liquid–liquid microextraction; fish samples; gas chromatography; priority substances; sulfuric acid treatment; tandem mass spectrometry.