The attraction of using an immunoaffinity column with HPLC was first recognised in 2011, when AOAC adopted this procedure as a First Action Method.

In the September/October issue of the Journal of AOAC International, Esther Campos Giménez from the Nestlé Research Center in Switzerland has made improvements to the original procedure and provided further in-house validation data for additional infant formulas and adult/paediatric nutritionals.

The improved method uses UHPLC, giving an impressively sharp peak with a three and a half minute elution time for vitamin B12. The method has been shown to be applicable for the determination of vitamin B12 in all forms of infant, adult, and/or pediatric formula (powders, ready-to-feed liquids, and liquid concentrates), made from any combination of milk, soya, rice, whey, hydrolysed protein, starch, and amino acids, with and without intact protein.