Tetramethylurea

2,3,7,8-Tetrachloro[13C12]dibenzo-p-dioxin, 1.2ml x 50ug/ml, toluene

2-tert-Butylphenol

2,2',3,3',4,4',5-Heptabromodiphenyl ether, 1.2ml x 50ug/ml, nonane