EPA Method 552,552.1,552.2 Internal Std Back Catalog number: 30105 Manufacturer: ABSOLUTE STANDARDS Availability: In the manufacturer's stock Price on request - + Recommended 71783 N-Phenyl-N’-cyclohexyl-p-phenylenediamine Price on request 91819 Quinoxaline-2-carboxylic acid Price on request S-4053-20K-TX5 Thiophene in Toluene Units: 5x1mL ampoule, 1x10mL screw-capped bottle Chiron No. Concentration µgS/g (ppm) Wt.% S-4053-0 Blank 0 S-4053-K 1 000 0.1000 S-4053-2.5K 2 500 0.2500 S-4053-5K Price on request