EPA Method 507 - Internal Standard Back Catalog number: 19031 Manufacturer: ABSOLUTE STANDARDS Availability: In the manufacturer's stock Price on request - + Recommended L-PFOS Sodium perfluoro-1-octanesulfonate, 1.2ml x 50ug/ml, methanol Price on request 10890.12-100-T 3-Nitrobiphenyl,100 µg/mL,toluene,1mL, Price on request 676747 Sodium perchlorate monohydrate, 100 µg/ml, Water, Price on request