Dionex Application Note 266: Determination of Sialic Acids

Dionex has released a method for simple determination of sialic acids that are present in infant formula in the pmol range. Application Note 266: Determination of Sialic Acids Using UHPLC with Fluorescence Detection demonstrates that N-acetylated sialic acids can be determined and O-acetylated sialic acids can be identified in infant formula samples using high-performance liquid chromatography (HPLC) with fluorescence detection following acid hydrolysis and 1,2-diamino-4,5-methylenedioxybenzene dihydrochloride (DMB) derivatisation. By using a water:acetonitrile gradient, high resolution of the sialic acids can be obtained in a 20 min analysis time, compared to the common 40 min isocratic method. The described assay uses a short-format Acclaim RSLC 120 C18 column that allows fast run times. The lower flow rate and shorter run time requires less acetonitrile than other published methods. The sensitivity of the Dionex FLD-3400RS fluorescence detector easily allows determination of sialic acids in the infant formula that are present in the pmol range. The sensitivity provides for simple determination of Neu5Ac, Neu5Gc, and O-acetylated sialic acids in the derivatised samples.