Table 2.

The different ultrasonic bath extraction conditions (see Figure 3).

Number	Individual experiments	Extraction conditions
(1)	Effect of extraction solvent	Methanol concentration (30%, 50%, 70%, and 100% aqueous methanol), solvent volume 100 mL, and extraction time 30 min
(2)	Effect of ultrasonic time	Extraction time (10, 20, 30, and 40 min), extraction solvent 70% aqueous methanol, and the ratio sample/extraction solvent 3/100 (g/mL)
(3)	Effect of solvent volumes	The ratio sample/extraction solvent (3/50, 3/100, and 3/150 g/mL), extraction solvent 70% aqueous methanol, and extraction time 30 min