Prepared for the DIN/CEN draft method on PCBs in Waste Oil 10 μg/mL of each analyte in n-Hexane. PCB 18. 2,2',5-Trichlorobiphenyl PCB 20. 2,3,3'-Trichlorobiphenyl PCB 28. 2,4,4'-Trichlorobiphenyl PCB 31. 2,4',5-TrichlorobiphenylPCB 44. 2,2',3,5'-Tetrachlo