Triflumizole, 100 µg/ml, Cyclohexane, 5ml

N-(4-chloro[13C6]phenyl)-N'-(3,4-dichloro[13C6]phenyl)[13C]urea , 1.2ml x 50ug/ml, methanol

Sildenafil citrate,1000 µg base/mL,MeOH,1mL

Formaldehyde