## 1 Introduction  
_Folimn Artemisia argyi_ (FAA), derived from the leaves of the perennial plant _Artemisia argyi_, has been widely used as an herbal medicine for centuries from a historical perspective. It is renowned for its diverse therapeutic effects, including antibacterial, antiviral, anti-anisthmatic, antitussive, expectorant, and anticancer properties [1, 2]. Simultaneously, rich in various active compounds, such as essential oils, organic acids, flavonoids, polysaccharides, terpenoids, amino acids, coumarins, and other foodborne phytochemicals [3], FAA has been scientifically proven to offer significant health benefits, including antioxidation [4], anti-fatigue [5], and obesity prevention [6]. Given the high nutritional value and unique aroma, FAA is widely applied as a food ingredient in the fields of tea and other food products. Specifically, the tea made from FAA (called FAA tea) is highly favored in Asian countries, like China, Japan, and South Korea, for its unique flavor.  
Despite prior studies on the biochemical components and biological characteristics of FAA [1, 7], research focusing on the flavor of FAA tea is rarely reported. Key gaps include the absence of standardized harvest times and a lack of understanding regarding the variation in flavor metabolites during its growth and development. Up to now, it is generally believed that harvest times of plants have significant effects on the bioactive components and quality of plant-derived compounds. [PERSON] et al. observed higher amino acid and catechin levels in early spring tea compared to other harvest periods [8], while [PERSON] et al. found that the phenolic content of purslane in later harvests was up to 30 times higher than in earlier ones [9]. Similarly, [PERSON] et al. reported seasonal variations in volatile compounds of _Citrus reticulata 'chachi'_ peel, with green flavors dominating from July to October and fruity notes from November to December [10]. These studies suggest that harvest timing could critically affect the flavor and metabolite profile of FAA tea.  
Obviously, emerging metabolomics technologies have allowed for the simultaneous detection of hundreds of endogenous metabolites and have been widely used in plant physiology, stress tolerance, phytochemistry, and flavor studies [11; 12], as well as in food science [13]. [PERSON] et al. utilized LC/MS-based metabolomics and GC/MS analysis to improve the taste and aroma of Keemun black tea through solid-state fermentation [14]. [PERSON] et al. characterized the floral and chestnut aromas in green tea using GC-MS and HS-GC-IMS [15]. [PERSON] et al. used UPLC-MS/MS to quantify hydrated catechins, caffeine, gallic acid, theanine, and theaflavins in tea plants [16]. These references demonstrate the potential of metabolomics in flavor studies and its applicability to FAA tea.  
Based on this, ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS), and headspace solid-phase microextraction two-dimensional gas chromatography time-of-flight mass spectrometry (HS-SPME/GC\(\times\)GC-TOFMS) were employed to analyze the non-volatile and volatile compounds of FAA tea across four harvest periods (March, April, May, and June). Principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) were used to compare component differences among samples, while antioxidant assays evaluated the in vitro antioxidant capacity of FAA tea. To our knowledge, this is an important comprehensive investigation into the flavor characteristics and metabolite profiles of FAA tea at different harvest times. The findings will provide valuable data and theoretical insights for optimizing the harvest period to achieve the best flavor in FAA tea.