Objective: To investigate the occurrence and concentrations of melamine and its analogues in tainted infant formula and to identify the etiologic factors for the urinary stones epidemic in infants and young children in China in 2008.
Methods: Sanlu infant formula samples were collected from families of the affected children in Gansu province, and markets in Gansu and Hebei provinces and Beijing city. Melamine and its analogues, including cyanuric acid, ammeline, and ammelide were measured by gas chromatography/tandem mass spectrometry.
Results: High prevalence and concentrations of melamine were found in Sanlu infant formula samples, with low concentrations of cyanuric acid, ammeline and ammelide. Melamine were detected in 87 out of 111 Sanlu infant formula samples with a range of 118 to 4,700 mg/kg.
Conclusion: The results provide strong evidence for melamine as the etiological factor for the urinary stones epidemic in infants and young children in China in 2008.