Table 4.

The chemical composition of oils extracted using the dual-function GC/MS optimized ultrasound-assisted hydrodistillation prototype (DF-GC/MS-HUD prototype), and the conventional Clevenger hydrodistillation (CCH) methods.

Composition (%)
Chemical nature/no	RT	Compounds	CCH EO	DF-GC/MS-HUD EO
Alcohols
1	5.73	1-Octanol	0.08 ± 0.01	0.15 ± 0.01*
2	6.04	Linalool	1.28 ± 0.01	2.24 ± 0.01*
3	7.27	Trans-p-Mentha-2,8-dien-1-ol	0.04 ± 0.01	1.20 ± 0.01*
4	7.44	Cis-p-Mentha-2,8-dien-1-ol	Tr	2.40 ± 0.01*
5	8.00	α-Terpineol	0.40 ± 0.01	1.10 ± 0.01*
6	8.23	(E)-Carveol	0.03 ± 0.01	2.20 ± 0.01*
7	8.29	(Z)-Carveol	0.06 ± 0.01	1.11 ± 0.01
8	8.96	p-Mentha-1,8-dien-9-ol	0.05 ± 0.01	0.33 ± 0.01
Aldehydes
9	7.08	Nonanal	0.14 ± 0.01	0.15 ± 0.01
10	5.05	Octanal	0.57 ± 0.01	Tr
11	7.54	Citronellal	0.20 ± 0.01	Tr
12	8.09	Decanal	0.55 ± 0.01	0.44 ± 0.01
13	8.42	β-Citral	0.20 ± 0.01	0.18 ± 0.01
14	8.71	α-Citral	0.25 ± 0.01	0.20 ± 0.01
15	9.12	Dodecanal	0.15 ± 0.01	Tr
16	12.96	β-Sinensal	0.13 ± 0.01	Tr
17	14.54	α-Sinensal	0.08 ± 0.01	Tr
18	8.81	Perillaldehyde	0.08 ± 0.01	0.40 ± 0.01
Ketone
19	8.49	Carvone	0.05 ± 0.01	3.40 ± 0.01*
Terpenes
20	4.34	α-Pinene	2.10 ± 0.01	4.20 ± 0.01*
21	4.75	Sabinene	1.13 ± 0.01	2.24 ± 0.01*
22	4.90	β-Myrcene	5.33 ± 0.01	7.55 ± 0.01*
23	5.13	3-Carene	0.54 ± 0.01	0.74 ± 0.01*
24	4.49	Limonene	60.23 ± 0.01	81.32 ± 0.01*
25	9.79	α-Copaene	0.11 ± 0.01	Tr
26	9.90	β-Cupepene	0.12 ± 0.01	Tr
27	9.95	Valencene	0.20 ± 0.01	0.38 ± 0.01
28	11.05	α-Farnesene	0.05 ± 0.01	0.99 ± 0.01*
Epoxide
29	7.37	Limonene 1,2-epoxide	Tr	2.88 ± 0.01*
Total			96.03 ± 0.01	97.17 ± 0.01

*Indicates a significant difference between Conventional CCH and prototype methods (p < 0.05).

“tr.” Indicates less than 0.01, RT, retention times.