CAS 1420043-51-1 appears in our catalog under these names: Sulfapyrazole 13C6 (sulfanilamide ring 13C6), 13C6-Sulfapyrazole, Concentration: 100 µg/ml Solvent: Methanol, 13C6-Sulfapyrazole. Offered by: Dr. Ehrenstorfer, HPC Standards. Available pack sizes: 10mg, 1x1ml, 1x10mg.