Interference Standard 4

p-Xylene, 1000µg/mL, Solvent-methanol, Unit 1mL, # of units-1, Cas.no. 106-42-3

EPA Method 624 Internal / Surrogate Standard

2-Hydroxy-4-methoxybenzophenone-5-sulfonic acid hydrate (contains 5-10% isopropyl alcohol), neat, Solvent-neat, Unit 100mg, # of units-1, Cas.no. 4065-45-6