Table 2 Recovery (R), recovery relative standard deviation (RSD) and limit of quantiﬁcation (LOQ) of individual PAHs from vegetable oil spiked samples (n = 3) Concentrations of the analyzed compounds in spiked samples were 25 pg g-1 Table 3 Recovery (R), recovery relative standard deviation (RSD), limits of quantiﬁcation (LOQ) and ionization parameters for the studied PBDE congeners Excitation energy [V] R (n = 9) [%] RSD (n = 9) [%] LOQ (S/N = 10) [pg g-1] R (%) 64.0 71.3 84.2 95.7 92.2 78.6 94.0 100.8 RSD (%) 12 8 6 8 10 9 6 6 LOQ (pg/ll) 1 0.5 0.5 0.1 0.1 0.1 0.1 0.1 kex (nm) 270 270 270 274 260 260 254 254 kem (nm) 340 340 340 375 420 420 390 390 PAHs (Abbrev.) Chry B[b]F B[k]F B[a]P DB[ah]A B[ghi]P IndP Precursor ion [m/z] 246 ± 4 326 ± 4 Product ion [m/z] 139 ? 167 217 ? 219 ? 245 ? 247 404 ± 4 295 ? 297 ? 325 ? 327 484 ± 4 375 ? 377 ? 403 ? 405 565 ± 4 799 ± 8 455 ? 457 638 ? 640 ? 642 ? 718 ? 720 ? 722 3.3 3.8 4.1 4.3 5.5 6.9 392 PAHs (Abbrev.) Naf Acy&Ace Fluo Phe Ant Flua Pyr B[a]A Congener 17 28 71 47 66 100 99 85 154 153 138 183 190 209a a At 2.5 ml min-1 dumping gas ﬂow rate R and RSD given as a mean value of three replicated at three concentration levels (3,60 and 240 pg g-1 congener-1, n = 3 9 3 = 9) prepared by mixing concentrated sulfuric acid 96% with silica gel, while basic (KOH impregnated) silica gel was prepared by mixing a methanol solution of KOH with silica gel and drying the obtained mixture for 30 min at 130 C. Sodium sulfate was heated for 4 h at 450 C before use and stored in an desiccator over a silica-based moisture absor- ber. Laboratory-made semi-permeable membranes were prepared from a 80 mm thick low-density polyethylene (LDPE) walls of 250 9 25 mm lay ﬂat tubing obtained from Artfolie (Bielsko-Biala, Poland). LDPE was extracted for 7 days with n-hexane before use. High purity ([97%) native PCB standards (IUPAC 28, 43, 52, 77, 81, 101, 105, 114, 118, 123, 126, 138, 146, 153, 156, 157, 167, 169, 180, 189, 194, and 209) and PAH standards (Naf, Acy, Ace, Fluo, Phe, Ant, Flua, Pyr, B[a]A, Chry, B[b]F, B[k]F, 123 B[a]P, DB[ah]A, B[ghi]P, IndP) were supplied by Dr Ehrenstorfer (Augsburg, Germany). 13C12-labelled standards (IUPAC 77, 81, 105, 114, 118, 123, 126, 156, 157, 167, 169, 189) and native polybrominated biphenyl ethers standards (IUPAC 17, 28, 47, 66, 71, 85, 99, 100, 138, 153, 154, 183, 190, 209) were obtained from Cambridge Isotope Laboratories (Andover, MA, USA). Silica gel Discovery DSC-Si SPE cartridges (5 g) and Superclean Envicarb-PSA cartridges (1 g) were obtained from Supelco (Bellefonte, PA, USA). Determination of Pesticides Determinations were conducted on a Thermo-Finnigan Trace GC Ultra gas chromatograph (Austin, TX, USA) R (%) 93.5 92.5 87.8 94.2 98.9 92.8 92.5 111.11 104.53 84.56 93.54 78.72 85.28 106.23 112.20 70.61 79.20 75.11 81.13 74.13 63.52 J Am Oil Chem Soc (2012) 89:389–400 RSD (%) 7 13 11 8 6 11 9 LOQ (pg/ll) 0.1 0.1 0.1 0.1 0.3 0.1 0.3 kex (nm) 254 260 260 260 260 260 293 kem (nm) 390 420 420 420 420 420 498 5.68 11.93 13.33 13.26 12.87 10.06 13.73 15.06 13.55 12.08 5.57 11.41 6.26 12.15 0.9 1.0 0.6 0.8 0.6 1.1 0.8 0.6 2.1 1.2 2.3 2.2 3.1 120.0