## 1 Introduction  
Flowers used as tea sources have lasted for centuries due to their unique taste and aroma. _Chrysanthemum_ tea is one of the mostly consumed flower teas, with a large family of _Chrysanthemum_ species. _Chrysanthemum morifolium_ (namely Hangbaiju in China) is one of the _Chrysanthemum_ teas with good fame. _Chrysanthemum morifolium_ planted in Tongxiang (Zhejiang Province, China) is one of the China Protected Geographical Indication Products with high commercial value. Despite its unique taste and aroma, _Chrysanthemum morifolium_ also has medical benefit such as antipyretic and sedative effects, reducing blood pressure and reducing eye strain [1].  
Chlorogenic acid, luteolin-7-\(O\)-glucoside, and 3,5-\(O\)-dicaffeoylquinic acid are the main active ingredients in _Chrysanthemum morifolium_. Medical benefits of these three ingredients have been reported in literature [2; 3; 4]. Determination of chlorogenic acid, luteolin-7-\(O\)-glucose, and 3,5-\(O\)-dicaffeoylquinic acid content is of great importance for quality monitoring of _Chrysanthemum morifolium_. Traditional methods such as high-performance liquid chromatography (HPLC) listed in the Chinese Pharmacopoeia [5] are used for chlorogenic acid, luteolin-7-\(O\)-glucose, and 3,5-\(O\)-dicaffeoylquinic acid measurement. Laboratory-based chemical methods are time-consuming, high cost, reagent-wasteful, and sample-destructive, and these techniques need complex operation skills. Although these methods can obtain accurate measurement results, they cannot be used to measure a large batch of samples in a short time. Thus, rapid, nondestructive, and accurate techniques are needed.  
Hyperspectral imaging is one of the rapid and nondestructive techniques. Hyperspectral imaging integrates imaging technique and spectroscopy technique, and it can acquire spatial and spectral information simultaneously. Due to this characteristic, hyperspectral imaging has been used in various fields, such as food [6; 7], agriculture [8; 9], medicine [10; 11], and so forth. Hyperspectral imaging can acquire spectral information of each pixel within the research samples, and hyperspectral images can be analyzed at pixelwise level [12; 13].  
Generally, dry _Chrysanthemum morifolium_ are stored and consumed in the market. The fresh _Chrysanthemum morifolium_ are harvested, undergo enzyme deactivation, and are dried. Determination of quality attributes of dry _Chrysanthemum morifolium_ is important for _Chrysanthemum morifolium_ trade and consumption. Moreover, it is important to determine quality attributes of fresh _Chrysanthemum morifolium_ during harvest. Knowing quality attributes will help to optimize the harvest time and procedure of _Chrysanthemum morifolium_, and the quality sorting can be conducted during harvest. Our previous study has proven the feasibility of using hyperspectral imaging to determine total polysaccharides and total flavonoids in dry _Chrysanthemum morifolium_[14]. The feasibility of using hyperspectral imaging to determine more chemical compositions for quality sorting and monitoring of _Chrysanthemum morifolium_ should be further studied.  
The objective of this study was to determine chlorogenic acid, luteolin-7-\(O\)-glucose, and 3,5-\(O\)-dicaffeoylquinic acid content in fresh and dry _Chrysanthemum morifolium_ using hyperspectral imaging. The specific objectives were to: (1) develop calibration models of chlorogenic acid, luteolin-7-\(O\)-glucose, and 3,5-\(O\)-dicaffeoylquinic acid content determination in fresh and dry _Chrysanthemum morifolium_ flowers; (2) compare the performances of chemical composition determinations in fresh and dry _Chrysanthemum morifolium_; (3) form distribution maps of chlorogenic acid, luteolin-7-\(O\)-glucose, and 3,5-\(O\)-dicaffeoylquinic acid.