EPA Method 525 Internals & Surrogates Back Catalog number: 91161 Manufacturer: ABSOLUTE STANDARDS Availability: In the manufacturer's stock Price on request - + Recommended 1733.18-K-IO 1,2-Benz[a]anthraquinone, 1000µg/mL, Solvent-isooctane, Unit 1mL, # of units-1, Cas.no. 2498-66-0 Price on request 675651 Pyridalyl, 100 µg/ml, Ethyl acetate, 5ml Price on request 33005 EPA Method 502/524 Fortification Solution Price on request