Development of a Methodology for Determination of Dioxins and Dioxin-like PCBs in Meconium by Gas Chromatography Coupled to High-Resolution Mass Spectrometry (GC-HRMS).

An analytical strategy was applied to investigate polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (dl-PCBs) in newborn meconium samples. The methodology includes extraction by selective pressurized liquid extraction (SPLE), followed by a clean-up multicolumn step. The samples were injected by gas chromatography coupled to a high-resolution mass spectrometer (GC-HRMS). The surrogate recoveries ranged from 68% to 95%, and the average of the limit of quantification (LOQ) ranged from 0.03 to 0.08 pg g -1 wet weight (ww) for PCDD/Fs and 0.2 to 0.88 pg g -1 ww for dl-PCBs. The strategy was applied to 10 samples collected in Valencia (Spain) in 2022. In total, 18 out of 29 analysed congeners were detected in at least one sample, whereas 6 of them were detected in all the samples (OCDD, PCB-123, PCB-118, PCB-105, PCB-167, and PCB-156). The levels for the sum of the 17 congeners of PCDD/Fs and 12 congeners of dl-PCBs in the upper-bound (UB), expressed as picograms of toxic equivalency quantity (TEQ) per gram of ww, ranged from 0.19 to 0.31 pg TEQ g -1 ww.