Table 2. Method Validation for Quantitating Terpenoids in Plant Materials by Headspace GC–MS^a.

		limit (ppm)		recovery (%)			RSD (%)
ID	analyte	MDL	MRL	low (10 ppm)	mid (125 ppm)	high (350 ppm)	intraday	interday
1	α-pinene	0.95	10.0	84.2	86.4	83.3	1.34	8.70
2	camphene	0.87	10.0	83.3	86.2	85.1	0.85	7.33
3	β-myrcene	1.13	10.0	82.8	89.1	87.9	1.19	4.77
4	(−)-β-pinene	1.03	10.0	80.6	88.5	86.4	1.07	4.12
5	δ-3-carene	1.28	10.0	83.4	89.0	85.5	0.90	3.41
6	α-terpinene	1.72	10.0	99.5	93.6	84.8	1.90	11.2
7	cis-β-ocimene	1.57	10.0	74.2	97.4	88.5	1.95	7.60
8	(+)-limonene	1.37	10.0	80.4	91.5	85.2	1.25	6.38
9	p-cymene	1.19	10.0	70.2	81.8	82.8	1.30	6.92
10	trans-β-ocimene	1.36	10.0	90.5	95.6	89.3	1.07	6.36
11	8-cineole (eucalyptol)	0.93	10.0	81.8	95.1	92.7	1.39	8.71
12	γ-terpinene	0.94	10.0	84.0	101	89.1	0.90	6.02
13	terpinolene	1.39	10.0	93.4	87.5	85.9	2.11	5.77
14	cis-linalool oxide	2.10	10.0	93.3	96.9	91.6	3.65	6.76
15	trans-linalool oxide	1.32	10.0	95.3	102	102	2.32	5.76
16	linalool	1.09	10.0	97.4	103	99.0	1.24	2.29
17	(−)-isopulegol	1.19	10.0	94.9	95.0	101	1.81	4.79
18	α-terpineol	1.41	10.0	91.5	96.1	102	2.58	6.21
19	citronellol	1.30	10.0	79.5	90.4	101	1.76	4.91
20	nerol	3.15	10.0	104	98.0	96.6	2.13	9.41
21	geraniol	2.01	10.0	79.3	93.5	90.8	3.74	5.67
22	β-damascenone	1.15	10.0	96.5	95.9	91.5	2.14	3.15
23	β-caryophyllene	2.43	10.0	110	99.9	85.3	1.87	5.10
24	β-damascone	0.98	10.0	88.5	90.1	91.5	2.02	6.41
25	α-humulene	2.49	10.0	87.6	98.2	84.8	2.38	5.61
26	cis-nerolidol	2.02	10.0	86.9	86.8	94.0	2.38	8.10
27	trans-nerolidol	2.54	10.0	90.1	87.8	95.3	1.50	4.29
28	(−)-guaiol	1.77	10.0	95.0	92.5	99.4	2.20	4.75
29	(−)-caryophyllene oxide	3.10	10.0	108	104	129	3.46	6.05
30	(−)-α-bisabolol	2.42	10.0	87.5	87.1	93.0	2.83	5.80

^aConcentrations are presented based on the plant weight. MDL: method detection limit. MRL: method reporting limit. The calibration ranges were from 2.5 to 400 ppm (25–4000 ppb in the vial), except for nerol and (−)-caryophyllene oxide (5–400 ppm in samples or 50–4000 ppb in the vial).