Application of the method of infrared spectrometry in the middle range for the determination of melamine in milk

Abstract

Currently, cases of sale of counterfeit dairy products in the retail network have become more frequent, including those containing melamine, which contributes to an increase in protein content. To assess melamine content and detect adulteration in milk and dairy products, accredited laboratories use the method of high-performance liquid chromatography, which is not used in production laboratories due to factors such as auxiliary equipment and chemical reagents. In accordance with TR CU "On the Safety of Milk and Dairy Products", the maximum permissible amount of melamine in milk should not exceed 1 mg/kg. The aim of the study was to identify melamine using infrared spectrometry in the mid-range. The research was carried out in stages at the educational and research center for Food and Animal Feed at St. Petersburg State University of Veterinary Medicine in 2024. The objects of research were raw milk samples without melamine, raw milk samples with different concentrations of melamine and a standard melamine sample. As a result of the studies, a correlation between the intensity of absorption bands in IR spectra of melaminecontaining milk and its concentration was established. Additionally, an absorption band that allows identifying the presence of melamine was found in the IR spectrum.