EPA Method 525 - Internal Standard Back Catalog number: 30031 Manufacturer: ABSOLUTE STANDARDS Availability: In the manufacturer's stock Price on request - + Recommended 8483.19-100-ME Metoprolol tartrate, 100µg/mL, Solvent-methanol, Unit 1mL, # of units-1, Cas.no. 56392-17-7 Price on request 2094.10-100MG Dimethyl phthalate, neat, Solvent-neat, Unit 100mg, # of units-1, Cas.no. 131-11-3 Price on request 674688 PSA-Mix 1 Price on request