EPA Method 509 Internal Standard Back Catalog number: 30097 Manufacturer: ABSOLUTE STANDARDS Availability: In the manufacturer's stock Price on request - + Recommended 674874 Difloxacin hydrochloride, 100mg Price on request DF-1478-S 1,4,7,8-Tetrachlorodibenzofuran, 1.2ml x 50ug/ml, nonane Price on request 50063 Potassium Nitrate as N Price on request