Table 3.
Retention time (RT), limit of detection (LOD) and of quantitation (LOQ), linearity range, determination coefficient (R 2), and regression equation of metabolites tested.
| Metabolitesa | RT | LOD | LOQ | Linearity range | R 2 | Regression equation |
|---|---|---|---|---|---|---|
| avg ± SD | ng/mL | ng/mL | ng/mL | |||
| 5-CQA | 1.62 ± 0.010 | 8.1 | 8.5 | 8.5–42,000 | 0.9993 | y = 1E + 07x |
| DHLc | 2.01 ± 0.009 | 2 | 5.7 | 5.7–35,000 | 0.9930 | y = 4E + 07x |
| Lc | 2.29 ± 0.007 | 6.4 | 13.7 | 13.7–70,000 | 0.9954 | y = 3E + 07x |
| 3,5-diCQA | 5.11 ± 0.033 | 9.3 | 66.5 | 66.5–62,000 | 0.9986 | y = 2E + 07x |
| DHdLc | 5.41 ± 0.023 | 9.5 | 18.1 | 18.1–50,000 | 0.9954 | y = 3E + 07x |
| dLc | 5.59 ± 0.023 | 4.1 | 11.4 | 11.4–10,000 | 0.9903 | y = 6E + 07x |
| DHLp | 8.74 ± 0.037 | 2.5 | 3.3 | 3.3–2,000 | 0.9645 | y = 4E + 07x |
| Lp | 8.88 ± 0.041 | 5.9 | 20.5 | 20.5–12,000 | 0.9910 | y = 3E + 07x |
a5-CQA: 5-mono-O-caffeoylquinic acid; DHLc: 11(S),13-dihydrolactucin; Lc: lactucin; 3,5-diCQA: 3,5-di-O-caffeoylquinic acid; DHdLc: 11(S),13-dihydro-8-deoxylactucin; dLc: 8-deoxylactucin; DHLp: 11(S),13-dihydrolactucopicrin; Lp: lactucopicrin.