13760.12 1,2,3,4-Tetrachlorodibenzo-p-dioxin-13C12 [114423-99-3] 8 ng/ml 13759.12 1,2,3,7,8,9-Hexachlorodibenzo-p-dioxin-13C12 [109719-82-6] 8 ng/ml 13758.12 '2,2',4,5,5'-Pentachlorobiphenyl-13C12 [104130-39-4] 20 ng/ml