Development of a certified reference material for the accurate analysis of the acrylamide content in infant formula

A certified reference material (CRM), KRISS CRM 108-02-006, was developed for the accurate analysis of low levels of acrylamide in infant formula matrices. The CRM is an infant formula fortified with acrylamide at a similar level as that stipulated by the European Union regulation for baby food. Commercially available infant formulas were processed by freeze-drying, and the subsequent homogenization of the fortified material to produce 961 bottles of the CRM in one batch. The CRM bottles containing approximately 15 g of the material in each unit were stored in a storage room at  - 70 ℃. High-purity acrylamide was used as the primary reference material, and its purity was assessed using an in-house mass-balance method to obtain results metrologically traceable to the International System of Units. The acrylamide content of the infant formula CRM was evaluated using isotope dilution-liquid chromatography/mass spectrometry as a reference method, which was established by our research group. An acrylamide content of 55.7 ± 2.1 μg/kg was assigned as the certified value of the CRM with the expanded uncertainty at a 95% confidence level. The homogeneity study showed good uniformity of the acrylamide content among units, providing a relative standard deviation of 1.2% of the mean value. A stability study was also performed by monitoring the CRM under different temperature conditions and periods. The stability results indicated that the acrylamide content in the CRM under the storage conditions of  - 70 ℃ remained stable for up to 10 months.