EPA Method 500 Series Internal Std #4

Coumaphos, 1000µg/ml in MeOH, 1ml

1-Naphthol, 1000µg/mL, Solvent-isopropanol, Unit 1mL, # of units-1, Cas.no. 90-15-3

Chlorothalonil, 100 µg/ml, Ethyl acetate, 5ml