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

3,4-Dihydroxyphenylglycolaldehyde (Dopegal), 1mg

PCB No. 156, 10µg/ml in Isooctane, 10ml

1,2,3,4,6-Pentachloronaphthalene, 1.2ml x 50ug/ml, nonane