Determination of urea, allantoin and lysine pyroglutamate in cosmetic samples by hydrophilic interaction chromatography

A new HPLC method using a Polyhydroxyethyl A column involving hydrophilic i nteraction chromatography (HILIC) is described for the simultaneous determi nation of urea, allantoin and lysine pyroglutamate in a cosmetic cream. Val idation of the method was accomplished with respect to linearity, repeatabi lity and Limits of detection/quantification. Compound recoveries approach 1 00% with acceptable RSD values. The method is very simple since no derivati sation is necessary. Furthermore, it allows the rapid and direct chromatogr aphic analysis of urea and hence could provide an alternative to other meth ods used to determine this compound in biological or cosmetic samples. (C) 2000 Elsevier Science B.V. All rights reserved.