EPA Method 551.1 Internal Standard Back Catalog number: 30103 Manufacturer: ABSOLUTE STANDARDS Availability: In the manufacturer's stock Price on request - + Recommended 59284 Potassium (K) Price on request 1028.16-500-IO 9-Ethylphenanthrene,500µg/mL,isooctane,1mL, Price on request 681777 Monomethyl phthalate, 250mg Price on request