1-(3,4-Dichlorophenyl)urea, 10 µg/ml, Acetonitril

delta-HCH, 10.0 µg/ml, Ethyl acetate, 10ml

Perfluoro-n-[13C8]octanoic acid, 50µg/ml in MeOH, 1,2ml

2,4-Dihydroxybenzophenone-13C6, 50µg/mL, Solvent-methanol, Unit 1mL, # of units-1, Cas.no. 131-56-6 (unlabelled)