EPA Method 500 Series Internal Std #4 Back Catalog number: 32003 Manufacturer: ABSOLUTE STANDARDS Availability: In the manufacturer's stock Price on request - + Recommended 73326 S-Metolachlor, 1000μg/mL in Acetone, 1ml Price on request 675159 Chlorthal-dimethyl, 250mg Price on request C11020500 Carbophenothion-methyl, 10mg Price on request