Heptachlor epoxide (Isomer B), 50mg

Atrazine-2-hydroxy, 100 µg/ml, Methanol, 1ml

3,3',4,4'-Tetrachloro[13C12]biphenyl, 1.2ml x 50ug/ml, nonane

PCB No. 21, 100µg/ml in Isooctane, 1ml