EPA Method 551.1 Internal Standard Back Catalog number: 32103 Manufacturer: ABSOLUTE STANDARDS Availability: In the manufacturer's stock Price on request - + Recommended A10946020AL-1000 Cannabidiolic acid (CBDA), 1000µg/mL in Acetonitrile, 1ml Price on request HPCHLOR-XEP Heptachlor-exo-epoxide (isomer B), 1.2mL x 100ug/mL, nonane Price on request 71570 p-Cresol-PFB derivative Price on request