Spectrum-Effect Relationship between HPLC Fingerprints and Antioxidant Activity of Yangyin Tongnao Prescription

Table 2

Independent variables and their levels.

Factors	Levels
	1	2	3
Temperature (°C)	50	60	70
Extraction time (min)	40	50	60
Solvent-to-material ratio (mL/g)	6	7	8
Deviation	1	2	3