Methotrexate Back Catalog number: 72209 Manufacturer: ABSOLUTE STANDARDS Availability: In the manufacturer's stock Price on request - + Recommended 11706.12-100-IO 3,3',4,5'-Tetrachlorobiphenyl ,100 µg/mL,isooctane,1mL, Price on request 52069 Spiking Standard 1 Price on request 96221 Piperonyl butoxide Price on request