EPA Method 500 Series Internal Std #4

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

Dichlorodifluoromethane, 20mg/mL in MeOH, 1ml

Paraxanthine, neat, Solvent-neat, Unit 50mg, # of units-1, Cas.no. 611-59-6