EPA Method 507 - Internal Standard Back Catalog number: 19031 Manufacturer: ABSOLUTE STANDARDS Availability: In the manufacturer's stock Price on request - + Recommended 66129 2,2’,3,3’,4,5-Hexachlorobiphenyl (129) Price on request 32951 1,4-Difluorobenzene Price on request BDF-138 1,3,8-Tribromodibenzofuran, 1.2ml x 50ug/ml, toluene Price on request