Oxalic acid, neat, Solvent-neat, Unit 1g, # of units-1, Cas.no. 144-62-7

Ibuprofen, 100 µg/ml, Methanol, 1ml

1,8-Naphthalic anhydride, neat, Solvent-neat, Unit 1g, # of units-1, Cas.no. 81-84-5

EPA Method 500 Series Internal Standard