Clavulanic acid dimer impurity1260617-10-4100 % similar Clavulanic acid58001-44-878 % similar Potassium clavulanate61177-45-553 % similar 1,2,3,4-Butanetetracarboxylic acid1703-58-831 % similar Propane-1,2,3-tricarboxylic acid99-14-931 % similar Ethylenediamine-N,N'-disuccinic acid20846-91-730 % similar