EPA Method 502.2 Internal Standard Back Catalog number: 91703 Manufacturer: ABSOLUTE STANDARDS Availability: In the manufacturer's stock Price on request - + Recommended 1281.30-10MG Betulinic Acid, neat, Solvent-neat, Unit 10mg, # of units-1, Cas.no. 472-15-1 Price on request 51096 8015AZ Calibration Standard Price on request 80601 EPA Method 8061 - Analytes Price on request