Comprehensive volatile profiling and origin authentication of sandalwood via a dual-mode HS-SPME-arrow-GC-MS strategy

Sandalwood (Santalum spp.) is highly valued for its timber, medicinal properties, and fragrance. The complexity of commercially available sandalwood varieties, coupled with increasing resource scarcity and market demand, has greatly complicated its quality control. In this study, headspace solid-phase microextraction arrow coupled with gas chromatography-mass spectrometry (HS-SPME-Arrow-GC-MS) was utilized to characterize volatile profiles and to explore the feasibility of discriminating the geographical origin of sandalwood. Specifically, the characteristic volatiles of sandalwood samples from diverse regions were profiled using a dual-mode strategy. Data acquisition was performed in full scan (SCAN) mode for non-targeted characterization and multiple reaction monitoring (MRM) mode for reference-free targeted analysis. This integrated method facilitated the detection of 51 and 90 volatile compounds in SCAN and MRM modes, respectively, thereby broadening the chemical characterization of the sandalwood volatile profile. Through multivariate statistical models (PLS-DA), 21 differential markers were identified based on their discriminative potential. Furthermore, quantitative analysis of key characteristic markers was performed using standard calibration curves, revealing significant concentration variations among samples from different geographical origins. In summary, this study presents a rapid, solvent-free, and highly sensitive analytical framework based on HS-SPME-Arrow-GC-MS coupled with dual-acquisition and multivariate modeling. By enabling broader chemical coverage, efficient targeted detection, and externally validated origin prediction, this approach offers improvements over conventional methods and provides a practical, reliable solution for the geographical authentication and quality control of sandalwood.