EPA Method 8021B Internal Standard Back Catalog number: 19394 Manufacturer: ABSOLUTE STANDARDS Availability: In the manufacturer's stock Price on request - + Recommended 679879 4,4'-Diaminodiphenyl sulfide, 100 µg/ml, Acetonit Price on request 674478 2,3,4-Trichloroanisole, 100mg Price on request 51184 LUST Retention Time Standard Price on request