An Optimized and Validated QuEChERS-Based Method for the Determination of PCBs in Edible Aquatic Species

In the present research, a quick, easy, cheap, effective, rugged, and safe (QuEChERS) method was optimized and validated for the determination of 14 selected PCB congeners in mussel (Mytilus galloprovincialis) and fish samples (Sparus aurata). The optimization included the selection of different QuEChERS procedures, extraction solvent, sample weight, and suitable sorbents for the clean-up step to achieve high sensitivity and minimal matrix interferences simultaneously. The identification and quantification of the selected PCBs were carried out using GC–MS. The method was validated providing in all cases excellent linearity (r² above 0.99). Recoveries were estimated at three different fortification levels (10, 50, and 100 ng g⁻¹) and ranged from 72.5 to 109.5% and 72.1 to 88.4% for mussel and fish samples, respectively. In addition, for both matrices, the LOQs ranged from 1 to 2.5 ng g⁻¹. The matrix effect was in all cases < 29%, while the expanded uncertainty U%, which was estimated at all the fortification levels, was found below 53% in all cases. Eventually, the optimized and validated method was applied to mussel and fish samples acquired from aquacultures in NW Greece, revealing the absence of the selected congeners in all cases.