EPA Method 500 Series Internal Std #4 Back Catalog number: 30003 Manufacturer: ABSOLUTE STANDARDS Availability: In the manufacturer's stock Price on request - + Recommended 70446 Phenacetin Price on request XA10333000ME Atrazine-2-hydroxy, 100µg/mL in MeOH, 1ml Price on request 90843 gamma-BHC Price on request