Simultaneous measurement of diazolidinyl urea, urea, and allantoin in cosmetic samples by hydrophilic interaction chromatography

A new HPLC method for simultaneous measurement of diazolidinyl urea (DU), urea, and allantoin by hydrophilic interaction chromatography using a column packed with triazol-bonded silica particles is described. The calibration curves of DU, urea, and allantoin were linear over the ranges 2.5–125.0, 30–1250, and 0.25–18.75 mg/L, respectively. The recoveries of DU, urea, and allantoin from homemade cosmetic samples ranged from 92.84% to 101.69%, 98.19% to 103.22%, and 95.75% to 102.09%, respectively. The peak relative standard deviation (RSD) values for the recovery tests of 3 concentrations/5 replicates were 3.03% for all compounds. In day-to-day measurement of recovery tests from homemade lotions over 3 consecutive days, the RSDs were less than 2.5% in all cases. This method was well validated and would be helpful for quickly analyzing these compounds in cosmetic samples.