Multidimensional validation of elemental fingerprint performance for small-scale rice geographic origin traceability and efficiency enhancement by multi-technology integration

This study systematically explored the application potential of rice elemental fingerprints in small-scale geographical origin tracing from the perspectives of spatial heterogeneity, temporal stability, and cross-cultivar applicability, and evaluated the enhancement effect of combining elemental fingerprints with stable isotopes on tracing accuracy. Analysis of 20 elements in 189 rice samples from nine production areas in Liaoning Province revealed significant spatial variations in the contents of Mn, Zn, Rb, Cu, and Ba. Chemometric analysis including PCA and PLS-DA revealed that the model based on 20 elements showed limited effectiveness in tracing the geographical origin of rice with complex varietal backgrounds. However, a two-year fixed-site trial of a single variety in Panjin, Dandong, and Yingkou demonstrated good temporal stability of Mn, Zn, Rb, and Ba. Further validation demonstrated that elements Mn, Rb, and Ba exhibited certain universality across tested varieties, whereas Sr and Zn showed varietal specificity. Moreover, the combination of characteristic elements with stable isotopes ( δ 15 N and δ 2 H) significantly enhanced the tracing effectiveness, exhibiting superior explanatory and predictive powers compared to models based solely on characteristic elements. These findings provide a scientific basis for the identification of rice geographical origins within small-scale geographical ranges.