EPA Method 507 - Internal Standard Back Catalog number: 19031 Manufacturer: ABSOLUTE STANDARDS Availability: In the manufacturer's stock Price on request - + Recommended S-4011-SET Whole Oil Quantitative Control Standards Set (S-4012+S-4013) Price on request 676233 Endosulfan-sulfate, 100 µg/ml, Cyclohexane, 1ml Price on request 10956.5-100-ME 3-Methyl-d3-2-buten-4,4,4-d3-1-thiol,100 µg/mL,MeOH,1mL Price on request