EPA Method 507 - Performance Check Solution Back Catalog number: 19030 Manufacturer: ABSOLUTE STANDARDS Availability: In the manufacturer's stock Price on request - + Recommended 94751 3,3’-Dimethylbenzidine Price on request 10288.14-200-T 1,8-Dimethylcarbazole Price on request S-4056-250-10MX Thiophene/2-Methylthiophene (2:1) in isooctane/Toluene(3:1); Units: 5x1mL ampoules, 1x10mL screw-capped bottle Chiron No. Concentration µgS/g (ppm) Wt.% S-4056-0 Blank 0 S-4056-5 5 Price on request