1-sulfomethyltetrazole-5-thiol disodium salt (SMT-DS) Chemical name: 1-sulfomethyltetrazole-5-thiol disodium salt Molecular formula: C2H2N4O3S2Na2 Molecular weight: 240.17 CAS NO.: 66242-82-8 Appearance: white crystalline powder Assay: not less than 97% Usage: cefonicid intermediate. 25kg/drum