Elemental analysis of mulberry leaves from the Chongqing three gorges reservoir area by inductively coupled plasma-mass spectrometry

Background Elemental composition is an informative component of mulberry-leaf characterization because macro-and trace-element patterns reflect mineral accumulation and may complement profiling of organic constituents. However, published mineral data for mulberry le aves are derived mainly from other species or regions, and directly comparable multi-element data for Morus . alba L., Morus . cathayana Hemsl., and Morus . australis Poir. within the Chongqing Three Gorges Reservoir area remain limited. Establishing a regional elemental baseline is therefore useful for describing resource heterogeneity, while recognizing that elemental composition alone does not establish comprehensive medicinal, nutritional, or safety quality. Methods Seventeen batches of mulberry leaves representing three Morus species were collected from the Chongqing Three Gorges Reservoir area. Twenty-two inorganic elements were quantified by microwave digestion coupled with inductively coupled plasma-mass spectrometry (ICP-MS). Analytical performance was assessed using precision, repeatability, and spike-recovery tests. Pearson correlation analysis, principal component analysis (PCA), and hierarchical clustering were used as exploratory tools to characterize elemental covariation and sample-level mineral profiles. Results Potassium (K), calcium (Ca), magnesium (Mg), and phosphorus (P) were the most abundant measured elements, with mean concentrations of 17.653, 7.761, 4.012, and 2.489 mg/g, respectively. M . alba showed the highest mean K concentration (25.712 mg/g) and lower mean Ca and Mg concentrations than M . cathayana and M . australis. K was negatively correlated with Ca, Mg, and Ti ( P < 0.01), whereas Fe-Zn and V-Fe/Zn showed significant positive associations. Six principal components with eigenvalues > 1 explained 89.711% of the total variance; the leading loading sets included Al/Fe/V, Ca/Mg/Ti, and Ba/Mn/Se. Hierarchical clustering separated the 17 batches into six descriptive mineral-profile groups. Conclusion Microwave digestion-ICP-MS combined with exploratory multivariate analysis provides a useful preliminary elemental profile of mulberry leaves from the Chongqing Three Gorges Reservoir area. The observed differences among species and batches support further investigation of mineral accumulation, but the present sample size, absence of paired environmental measurements, and lack of external validation preclude claims of mechanistic ion interactions, comprehensive quality grading, or geographical authentication. Larger, multi-season studies integrating soil and cultivation variables are needed to validate the observed patterns.