Integrated Elemental Profiling and Fourier Transform Infrared Spectroscopy (FTIR) Fingerprinting for Geographical Origin Discrimination of Larimichthys crocea with Chemometrics

This study established an integrated analytical strategy combining elemental profiling via inductively coupled plasma mass spectrometry (ICP-MS) and spectral fingerprinting via Fourier transform infrared spectroscopy (FTIR) to discriminate geographical origins of Larimichthys crocea (L. crocea) from five coastal Chinese cities: Zhoushan, Taizhou, Wenzhou, Ningde, and Zhanjiang. Significant inter-origin variations (P<0.05) were observed in the mass fractions of 13 key elements: aluminium (Al), titanium (Ti), chromium (Cr), manganese (Mn), arsenic (As), selenium (Se), strontium (Sr), barium (Ba), mercury (Hg), lead (Pb), iron (Fe), nickel (Ni), and tin (Sn). Region-specific elemental signatures were identified: Taizhou samples demonstrated maximal Al, Se, and Hg content with minimal As levels; Zhoushan samples contained peak Ni concentrations; Wenzhou samples exhibited significantly elevated Ti, Cr, Mn, and Sr alongside minimal Se; whereas Zhanjiang samples showed maximal As levels with suppressed Al, Ti, Cr, Mn, Fe, Ni, Ba, and Pb.Multivariate chemometric analysis of the integrated ICP-MS/FTIR dataset, incorporating principal component analysis (PCA), cluster analysis (CA), and linear discriminant analysis (LDA), achieved precise discrimination among the five geographical origins. PCA revealed five distinct, non-overlapping clusters in the score plot (PC1/PC2 cumulative variance=74.7%). CA further confirmed independent clustering by origin. The LDA model achieved 100% accuracy in re-substitution validation and 97.3% in cross-validation. This work demonstrates that ICP-MS/FTIR integration augmented by chemometrics establishes a rapid, highly accurate platform for authenticating L. crocea geographical origin, providing a robust framework for safeguarding aquatic geographical indications.