Table 1 The four factors with three levels for orthogonal test.

From: Simultaneous detection of five flavoring agents in chewing gum by ultrasound-microwave synergistic extraction coupled with gas chromatography

Levels Factors
A
(Solvent)
B
(Solid-liquid ratio g:mL)
C
(Microwave power/W)
D
(Extraction time/min)
1 Ethanol 1:10 300 10
2 Ether 1:15 400 15
3 Petroleum ether 1:20 500 30