Determination of Sialic Acid in Milk and Products Using High Performance Anion-Exchange Chromatography Coupled with Pulsed Amperometric Detection

A resolved succinct environmental-friendly chromatographic method was developed for the determination of N-acetylneuraminic acid ( Neu5AC ) and N-glycolylneuraminic acid ( Neu5Gc ) in bovine milk and products using high-performance anion exchange chromatography coupled with pulsed amperometric detection. The conditions affecting the separation, detection and sialic acid release from milk were optimized. The separation was carried out on CarboPac PA20 anion-exchange column using 100 mmol/L NaOH, 20 - 300 mmol/L NaAc gradient eluting in 20 min at the flow rate of 0. 5 mL/min. The separation and detection temperature were both at 30 degrees C. The detection was carried out on a gold working electrode. The detection limits were 3. 0 and 1. 8 mu g/L and the linear range of 5 to 500 mu g/L was obtained (25. 0 mu L injection, three times of the baseline noise). The spiked recovery of Neu5AC and Neu5Gc in milk was 88% - 115%.