Abstract
Commercially available aqueous solutions of glutaraldehyde (GA) sometimes contain GA polymers as impurities which can cause undesirable effects. We found new type oligomers present in a GA solution as impurities and isolated them by reverse-phase high performance liquid chromatography. These compounds were identified as GA trimer, pentamer and heptamer having a 1, 3, 5-trioxane skeleton. In particular, GA trimer, 2, 4, 6-tris (4-oxobutyl) -1, 3, 5-trioxane, was named “paraglutaraldehyde” (para-GA). These compounds showed absorption maxima at 280 nm (the same position as GA), and hence could not be distinguished from GA itself by the conventional ultraviolet absorption method. These impurities were not detected in highly purified GA solution after storage under the conditions of practical use. Accordingly, these oligomers seemed to be formed by the intermolecular cyclization of GA monomer during the processes of synthesis.
