Региональные Особенности Элементного Профиля Коровьего Молока Центрального Казахстана

Cow’s milk is one of the most important foods of animal origin and may simultaneously serve as a source of both essential trace elements and potentially toxic elements for humans. Despite the widespread application of modern multi-element analytical techniques, regional characteristics of the elemental profile of milk using chemometric approaches remain insufficiently investigated in Kazakhstan. The aim of this study was to determine the concentrations of As, Be, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, V, and Zn in cow’s milk marketed in the cities of Karaganda and Zhezkazgan, compare their concentrations, and identify regional differences in the elemental profile. A total of 38 milk samples were analyzed, including 16 samples from Karaganda and 22 samples from Zhezkazgan. Following microwave-assisted acid digestion, elemental concentrations were determined by inductively coupled plasma mass spectrometry. Statistical analysis included the Mann-Whitney U test with Benjamini-Hochberg correction, Spearman’s rank correlation analysis, and principal component analysis. The highest concentrations in both regions were observed for Zn, Cr, and Ni, whereas Be and Cd where not detected in any of the analyzed samples. Statistically significant regional differences were found only for Cu and Hg (p <0,001), with higher concentrations in samples from Karaganda. Exceedances of the maximum permissible levels were identified in two samples for Hg and five samples for Pb. Correlation analysis revealed a common cluster of strongly associated elements (Cr-Mn-Co-Ni) in both regions, whereas principal component analysis demonstrated regional differences in the loading patterns of Hg, Cu, Zn, As, and V, reflecting differences in the elemental profiles. The findings indicate that regional variability is expressed not only in the concentrations of individual elements but also in the structure of their interrelationships. The application of chemometric approaches enabled the identification of hidden patterns in the formation of the milk elemental profile that could not be detected by comparing mean concentrations alone. Future research should focus on an integrated investigation of the «soil-feed-water-animal-milk» continuum using chemometric techniques to identify the major factors governing the transfer of chemical elements into milk. The result may contribute to regional milk safety monitoring programs and to the improvement of quality control systems for foods of animal origin.