pH 4.01 buffer solution (box of 25x20mL sachet)

Trimethoprim, >99%, 1g

4-Hydroxyisophthalic acid (4-Hydroxybenzene-1,3-dicarboxylic acid), neat, Solvent-neat, Unit 100mg, # of units-1, Cas.no. 636-46-4

EPA Method 525 - PAH Standard