13C3-Caffeine, 100 µg/ml, Methanol, 1ml

Diclofenac, 1000µg/ml in MeOH, 1ml

2,2',3,3',4,5,5',6,6'-Nonachlorobiphenyl (208)

1,2,3,7,8,9-Hexachloro[13C12]dibenzo-p-dioxin, 1.2ml x 50ug/ml, toluene